9129767 WBZK3IXM 1 apa 50 date desc year Severinghaus 18 https://jseveringhaus.scrippsprofiles.ucsd.edu/wp-content/plugins/zotpress/
%7B%22status%22%3A%22success%22%2C%22updateneeded%22%3Afalse%2C%22instance%22%3Afalse%2C%22meta%22%3A%7B%22request_last%22%3A150%2C%22request_next%22%3A50%2C%22used_cache%22%3Atrue%7D%2C%22data%22%3A%5B%7B%22key%22%3A%22M94XZK6X%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Grimmer%20et%20al.%22%2C%22parsedDate%22%3A%222025-03-28%22%2C%22numChildren%22%3A0%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EGrimmer%2C%20M.%2C%20Baggenstos%2C%20D.%2C%20Schmitt%2C%20J.%2C%20Krauss%2C%20F.%2C%20Shackleton%2C%20S.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20%26amp%3B%20Fischer%2C%20H.%20%282025%29.%20AMOC%20Modulates%20Ocean%20Heat%20Content%20During%20Deglaciations.%20%3Ci%3EGeophysical%20Research%20Letters%3C%5C%2Fi%3E%2C%20%3Ci%3E52%3C%5C%2Fi%3E%286%29%2C%20e2024GL114415.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1029%5C%2F2024GL114415%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1029%5C%2F2024GL114415%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22AMOC%20Modulates%20Ocean%20Heat%20Content%20During%20Deglaciations%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Markus%22%2C%22lastName%22%3A%22Grimmer%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Daniel%22%2C%22lastName%22%3A%22Baggenstos%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jochen%22%2C%22lastName%22%3A%22Schmitt%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Florian%22%2C%22lastName%22%3A%22Krauss%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Sarah%22%2C%22lastName%22%3A%22Shackleton%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jeffrey%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Hubertus%22%2C%22lastName%22%3A%22Fischer%22%7D%5D%2C%22abstractNote%22%3A%22Abstract%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20During%20deglaciations%2C%20Earth%20takes%20up%20vast%20amounts%20of%20energy%2C%20about%20half%20of%20which%20heats%20the%20global%20ocean.%20Thus%2C%20ocean%20heat%20content%20%28OHC%29%20is%20a%20key%20metric%20to%20assess%20Earth%27s%20energy%20budget.%20Recent%20modeling%20studies%20suggest%20that%20OHC%20changes%20not%20only%20in%20response%20to%20orbitally%20driven%20climate%20change%20but%20is%20also%20modulated%20on%20millennial%20timescales%20by%20the%20Atlantic%20Meridional%20Overturning%20Circulation%20%28AMOC%29.%20Here%2C%20we%20present%20the%20first%20OHC%20record%20for%20the%20last%20four%20deglaciations%20using%20noble%5Cu2010gas%20ratios%20in%20the%20EPICA%20Dome%20C%20ice%20core.%20The%20record%20reveals%20millennial%5Cu2010scale%20OHC%20variability%20in%20all%20studied%20deglaciations%2C%20most%20prominently%20as%20OHC%20maxima%20at%20the%20end%20of%20Terminations%20II%2C%20III%2C%20and%20IV.%20These%20millennial%5Cu2010scale%20OHC%20changes%20are%20anti%5Cu2010correlated%20with%20AMOC%20strength%2C%20suggesting%20that%20the%20AMOC%20modulates%20OHC%20across%20different%20climate%20states.%20Furthermore%2C%20given%20the%20magnitude%20of%20the%20end%5Cu2010of%5Cu2010termination%20OHC%20maxima%2C%20AMOC%5Cu2010induced%20OHC%20changes%20may%20be%20an%20important%20control%20of%20early%20interglacial%20atmospheric%20CO%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%202%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%2C%20sea%20level%2C%20and%20climate.%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%5Cn%20%20%20%20%20%20%20%20%20%20%2C%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20Plain%20Language%20Summary%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20Earth%27s%20energy%20balance%20determines%20whether%20the%20planet%20experiences%20a%20net%20gain%20or%20loss%20of%20energy.%20Due%20to%20its%20high%20heat%20capacity%2C%20the%20ocean%20is%20one%20of%20Earth%27s%20dominant%20energy%20reservoirs%20and%20ocean%20heat%20content%20%28OHC%29%20therefore%20a%20key%20metric%20to%20assess%20the%20global%20energy%20balance.%20Recently%2C%20OHC%20has%20been%20suggested%20to%20not%20only%20change%20on%20glacial%5Cu2013interglacial%20timescales%2C%20but%20to%20also%20be%20affected%20by%20ocean%20circulation%20on%20millennial%20timescales.%20Our%20OHC%20record%20reveals%20that%20millennial%5Cu2010scale%20OHC%20changes%20occur%20concomitantly%20with%20changes%20in%20ocean%20circulation%20across%20different%20climate%20states%20during%20the%20last%20four%20glacial%5Cu2013interglacial%20transitions.%20This%20suggests%20that%20ocean%20circulation%20plays%20a%20crucial%20role%20controlling%20millennial%5Cu2010scale%20ocean%20heat%20uptake%2C%20which%20has%20consequences%20for%20atmospheric%20CO%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%202%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%2C%20sea%20level%2C%20and%20climate.%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%5Cn%20%20%20%20%20%20%20%20%20%20%2C%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20Key%20Points%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20First%20ocean%20heat%20content%20%28OHC%29%20record%20covering%20the%20last%20four%20deglaciations%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20All%20studied%20deglaciations%20show%20millennial%20OHC%20variability%20anti%5Cu2010correlated%20with%20Atlantic%20meridional%20overturning%20circulation%20%28AMOC%29%20strength%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20Prominent%20OHC%20maxima%20at%20the%20ends%20of%20Termination%20II%5Cu2013IV%20point%20to%20AMOC%5Cu2010induced%20OHC%20changes%20as%20important%20control%20of%20early%20interglacial%20climate%22%2C%22date%22%3A%222025-03-28%22%2C%22language%22%3A%22en%22%2C%22DOI%22%3A%2210.1029%5C%2F2024GL114415%22%2C%22ISSN%22%3A%220094-8276%2C%201944-8007%22%2C%22url%22%3A%22https%3A%5C%2F%5C%2Fagupubs.onlinelibrary.wiley.com%5C%2Fdoi%5C%2F10.1029%5C%2F2024GL114415%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222025-04-17T18%3A43%3A50Z%22%7D%7D%2C%7B%22key%22%3A%228UXYP58T%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Martin%20et%20al.%22%2C%22parsedDate%22%3A%222024-12-28%22%2C%22numChildren%22%3A0%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EMartin%2C%20K.%20C.%2C%20Buizert%2C%20C.%2C%20Brook%2C%20E.%2C%20Williams%2C%20O.%20L.%2C%20Edwards%2C%20J.%20S.%2C%20Riddell%26%23x2010%3BYoung%2C%20B.%2C%20Fudge%2C%20T.%20J.%2C%20Mederbel%2C%20F.%2C%20Beaudette%2C%20R.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%2C%20Oyabu%2C%20I.%2C%20Kawamura%2C%20K.%2C%20Kirk%2C%20M.%2C%20Koldtoft%2C%20I.%2C%20Steffensen%2C%20J.%20P.%2C%20%26amp%3B%20Blunier%2C%20T.%20%282024%29.%20Greenland%20Ice%20Cores%20Reveal%20a%20South%26%23x2010%3BTo%26%23x2010%3BNorth%20Difference%20in%20Holocene%20Thermal%20Maximum%20Timings.%20%3Ci%3EGeophysical%20Research%20Letters%3C%5C%2Fi%3E%2C%20%3Ci%3E51%3C%5C%2Fi%3E%2824%29%2C%20e2024GL111405.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1029%5C%2F2024GL111405%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1029%5C%2F2024GL111405%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Greenland%20Ice%20Cores%20Reveal%20a%20South%5Cu2010To%5Cu2010North%20Difference%20in%20Holocene%20Thermal%20Maximum%20Timings%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Kaden%20C.%22%2C%22lastName%22%3A%22Martin%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Christo%22%2C%22lastName%22%3A%22Buizert%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ed%22%2C%22lastName%22%3A%22Brook%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Olivia%20L.%22%2C%22lastName%22%3A%22Williams%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jon%20S.%22%2C%22lastName%22%3A%22Edwards%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ben%22%2C%22lastName%22%3A%22Riddell%5Cu2010Young%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%20J.%22%2C%22lastName%22%3A%22Fudge%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Farhana%22%2C%22lastName%22%3A%22Mederbel%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ross%22%2C%22lastName%22%3A%22Beaudette%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jeff%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ikumi%22%2C%22lastName%22%3A%22Oyabu%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Kenji%22%2C%22lastName%22%3A%22Kawamura%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Marie%22%2C%22lastName%22%3A%22Kirk%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Iben%22%2C%22lastName%22%3A%22Koldtoft%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Steffensen%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Thomas%22%2C%22lastName%22%3A%22Blunier%22%7D%5D%2C%22abstractNote%22%3A%22Abstract%5Cn%20%20%20%20%20%20%20%20%20%20%20%20Holocene%20temperature%20evolution%20remains%20poorly%20understood.%20Proxies%20in%20the%20early%20and%20mid%5Cu2010Holocene%20suggest%20a%20Holocene%20Thermal%20Maximum%20%28HTM%29%20where%20temperatures%20exceed%20the%20pre%5Cu2010industrial%2C%20whereas%20climate%20models%20generally%20simulate%20monotonic%20warming.%20This%20discrepancy%20may%20reflect%20proxy%20seasonality%20biases%20or%20errors%20in%20climate%20model%20internal%20feedbacks%20or%20dynamics.%20Using%20seasonally%20unbiased%20ice%20core%20reconstructions%20at%20NEEM%2C%20NGRIP%2C%20and%20Greenland%20Ice%20Sheet%20Project%202%2C%20we%20identify%20a%20Greenland%20HTM%20of%20%5Cu223c2%5Cu00b0C%20above%20pre%5Cu2010industrial%2C%20in%20agreement%20with%20other%20Northern%20Hemisphere%20proxy%20reconstructions.%20The%20firn%5Cu2010based%20reconstructions%20are%20verified%20through%20borehole%20thermometry%2C%20producing%20a%20multi%5Cu2010core%2C%20multi%5Cu2010proxy%20reconstruction%20of%20Greenland%20climate%20from%20the%20last%20glacial%20to%20pre%5Cu2010industrial.%20HTM%20timing%20across%20Greenland%20is%20heterogenous%2C%20occurring%20earlier%20at%20high%20elevations.%20Total%20air%20content%20measurements%20suggest%20a%20temperature%20contribution%20from%20elevation%20changes%3B%20regional%20oceanographic%20conditions%2C%20a%20weakened%20polar%20lapse%20rate%2C%20or%20variable%20near%5Cu2010surface%20inversions%20may%20also%20be%20important%20sensitivities.%20Our%20reconstructions%20support%20climate%20simulations%20with%20dynamic%20Holocene%20vegetation%2C%20highlighting%20the%20importance%20of%20vegetation%20feedbacks.%5Cn%20%20%20%20%20%20%20%20%20%20%2C%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20Plain%20Language%20Summary%5Cn%20%20%20%20%20%20%20%20%20%20%20%20Climate%20change%20during%20the%20Holocene%2C%20the%20current%20geological%20time%20period%2C%20is%20important%20to%20understand.%20This%20period%20began%20%5Cu223c11.7%20thousand%20years%20ago%20and%20contains%20the%20transition%20from%20the%20last%20ice%20age%20to%20today.%20Simulations%20of%20this%20transition%20suggest%20that%20global%20climate%20continued%20to%20warm%20across%20this%20whole%20period.%20Proxy%20evidence%2C%20however%2C%20tends%20to%20suggest%20that%20warmer%5Cu2010than%5Cu2010modern%20temperatures%20were%20reached%20at%20the%20start%20of%20the%20Holocene%2C%20followed%20by%20gradual%20cooling.%20Resolving%20this%20dispute%20in%20our%20recent%20climatological%20past%20is%20important%20to%20verify%20climate%20model%20behavior%2C%20and%20understand%20nuances%20in%20proxy%20records.%20Using%20ice%20core%20reconstructions%20of%20Greenland%20climate%2C%20which%20broadly%20follows%20northern%20high%5Cu2010latitude%20climate%2C%20we%20lend%20further%20support%20to%20a%20warm%20period%20in%20the%20early%20Holocene.%20These%20new%20records%20are%20spread%20across%20Greenland%2C%20allowing%20for%20the%20spatial%20fingerprint%20of%20this%20warm%20period%20to%20be%20identified.%5Cn%20%20%20%20%20%20%20%20%20%20%2C%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20Key%20Points%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20We%20identify%20a%20Holocene%20Thermal%20Maximum%20%28HTM%29%20across%20three%20Greenland%20ice%20cores%20of%201.6%5Cu20132.6%5Cu00b0C%20above%20pre%5Cu2010industrial%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20The%20HTM%20has%20a%20south%5Cu2010to%5Cu2010north%20difference%20in%20timing%2C%20beginning%20earlier%20at%20Greenland%20Ice%20Sheet%20Project%202%20in%20the%20south%20%289.9%20ka%29%20and%20later%20at%20NEEM%20in%20the%20north%20%286.85%20ka%29%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20%20Total%20air%20content%20suggests%20that%20deglacial%20elevation%20change%20contributes%20to%20this%20timing%20difference%2C%20but%20cannot%20fully%20explain%20observed%20trends%22%2C%22date%22%3A%222024-12-28%22%2C%22language%22%3A%22en%22%2C%22DOI%22%3A%2210.1029%5C%2F2024GL111405%22%2C%22ISSN%22%3A%220094-8276%2C%201944-8007%22%2C%22url%22%3A%22https%3A%5C%2F%5C%2Fagupubs.onlinelibrary.wiley.com%5C%2Fdoi%5C%2F10.1029%5C%2F2024GL111405%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222025-01-14T22%3A05%3A31Z%22%7D%7D%2C%7B%22key%22%3A%22CATPPXZK%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Harris%20Stuart%20et%20al.%22%2C%22parsedDate%22%3A%222024-08-22%22%2C%22numChildren%22%3A0%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EHarris%20Stuart%2C%20R.%2C%20Landais%2C%20A.%2C%20Arnaud%2C%20L.%2C%20Buizert%2C%20C.%2C%20Capron%2C%20E.%2C%20Dumont%2C%20M.%2C%20Libois%2C%20Q.%2C%20Mulvaney%2C%20R.%2C%20Orsi%2C%20A.%2C%20Picard%2C%20G.%2C%20Pri%26%23xE9%3B%2C%20F.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%2C%20Stenni%2C%20B.%2C%20%26amp%3B%20Martinerie%2C%20P.%20%282024%29.%20On%20the%20relationship%20between%20%3Ci%3E%26%23x3B4%3B%3C%5C%2Fi%3E%20O%20%3Csub%3E2%3C%5C%2Fsub%3E%20%26%23x2215%3BN%20%3Csub%3E2%3C%5C%2Fsub%3E%20variability%20and%20ice%20sheet%20surface%20conditions%20in%20Antarctica.%20%3Ci%3EThe%20Cryosphere%3C%5C%2Fi%3E%2C%20%3Ci%3E18%3C%5C%2Fi%3E%288%29%2C%203741%26%23x2013%3B3763.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Ftc-18-3741-2024%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Ftc-18-3741-2024%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22On%20the%20relationship%20between%20%3Ci%3E%5Cu03b4%3C%5C%2Fi%3E%20O%20%3Csub%3E2%3C%5C%2Fsub%3E%20%5Cu2215N%20%3Csub%3E2%3C%5C%2Fsub%3E%20variability%20and%20ice%20sheet%20surface%20conditions%20in%20Antarctica%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Romilly%22%2C%22lastName%22%3A%22Harris%20Stuart%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ama%5Cu00eblle%22%2C%22lastName%22%3A%22Landais%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Laurent%22%2C%22lastName%22%3A%22Arnaud%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Christo%22%2C%22lastName%22%3A%22Buizert%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Emilie%22%2C%22lastName%22%3A%22Capron%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Marie%22%2C%22lastName%22%3A%22Dumont%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Quentin%22%2C%22lastName%22%3A%22Libois%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Robert%22%2C%22lastName%22%3A%22Mulvaney%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ana%5Cu00efs%22%2C%22lastName%22%3A%22Orsi%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ghislain%22%2C%22lastName%22%3A%22Picard%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Fr%5Cu00e9d%5Cu00e9ric%22%2C%22lastName%22%3A%22Pri%5Cu00e9%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jeffrey%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Barbara%22%2C%22lastName%22%3A%22Stenni%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Patricia%22%2C%22lastName%22%3A%22Martinerie%22%7D%5D%2C%22abstractNote%22%3A%22Abstract.%20While%20the%20processes%20controlling%20pore%20closure%20are%20broadly%20understood%2C%20the%20physical%20mechanisms%20driving%20the%20associated%20elemental%20fractionation%20remains%20ambiguous.%20Previous%20studies%20have%20shown%20that%20the%20pore%20closure%20process%20leads%20to%20a%20depletion%20in%20small-sized%20molecules%20%28e.g.%20H2%2C%20O2%2C%20Ar%2C%20Ne%2C%20He%29%20in%20ice%20core%20bubbles%20relative%20to%20larger-sized%20molecules%20like%20N2.%20This%20size-dependent%20fractionation%2C%20identified%20using%20ice%20core%20%5Cu03b4%28O2%5C%2FN2%29%20records%2C%20exhibits%20a%20clear%20anti-correlation%20with%20local%20summer%20solstice%20insolation%2C%20making%20%5Cu03b4%28O2%5C%2FN2%29%20a%20valuable%20ice%20core%20dating%20tool.%20Mechanisms%20controlling%20this%20relationship%20are%20attributed%20to%20the%20physical%20properties%20of%20deep%20firn.%20In%20this%20study%2C%20we%20compile%20%5Cu03b4%28O2%5C%2FN2%29%20records%20from%2015%20polar%20ice%20cores%20and%20show%20a%20new%20additional%20link%20between%20%5Cu03b4%28O2%5C%2FN2%29%20and%20local%20surface%20temperature%20and%5C%2For%20accumulation%20rate.%20Using%20the%20Crocus%20snowpack%20model%2C%20we%20perform%20sensitivity%20tests%20to%20identify%20the%20response%20of%20near-surface%20snow%20properties%20to%20changes%20in%20insolation%20intensity%2C%20accumulation%20rate%2C%20and%20air%20temperature.%20These%20tests%20support%20a%20mechanism%20linked%20to%20firn%20grain%20size%2C%20such%20that%20the%20larger%20the%20grain%20size%20for%20a%20given%20density%2C%20the%20stronger%20the%20pore%20closure%20fractionation%20and%2C%20hence%2C%20the%20lower%20the%20%5Cu03b4%28O2%5C%2FN2%29%20values%20archived%20in%20the%20ice.%20Based%20on%20both%20snowpack%20model%20outputs%20and%20data%20compilation%2C%20our%20findings%20suggest%20that%20local%20accumulation%20rate%20and%20temperature%20should%20be%20considered%20when%20interpreting%20%5Cu03b4%28O2%5C%2FN2%29%20as%20a%20local%20insolation%20proxy.%22%2C%22date%22%3A%222024-08-22%22%2C%22language%22%3A%22en%22%2C%22DOI%22%3A%2210.5194%5C%2Ftc-18-3741-2024%22%2C%22ISSN%22%3A%221994-0424%22%2C%22url%22%3A%22https%3A%5C%2F%5C%2Ftc.copernicus.org%5C%2Farticles%5C%2F18%5C%2F3741%5C%2F2024%5C%2F%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222024-10-14T17%3A10%3A40Z%22%7D%7D%2C%7B%22key%22%3A%22C3DMSPXP%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Hmiel%20et%20al.%22%2C%22parsedDate%22%3A%222024-07-25%22%2C%22numChildren%22%3A0%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EHmiel%2C%20B.%2C%20Petrenko%2C%20V.%20V.%2C%20Buizert%2C%20C.%2C%20Smith%2C%20A.%20M.%2C%20Dyonisius%2C%20M.%20N.%2C%20Place%2C%20P.%2C%20Yang%2C%20B.%2C%20Hua%2C%20Q.%2C%20Beaudette%2C%20R.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20Harth%2C%20C.%2C%20Weiss%2C%20R.%20F.%2C%20Davidge%2C%20L.%2C%20Diaz%2C%20M.%2C%20Pacicco%2C%20M.%2C%20Menking%2C%20J.%20A.%2C%20Kalk%2C%20M.%2C%20Fa%26%23xEF%3Bn%2C%20X.%2C%20Adolph%2C%20A.%2C%20%26%23x2026%3B%20Murray%2C%20L.%20T.%20%282024%29.%20Characterization%20of%20in%20situ%20cosmogenic%20%3Csup%3E14%3C%5C%2Fsup%3E%20CO%20production%2C%20retention%20and%20loss%20in%20firn%20and%20shallow%20ice%20at%20Summit%2C%20Greenland.%20%3Ci%3EThe%20Cryosphere%3C%5C%2Fi%3E%2C%20%3Ci%3E18%3C%5C%2Fi%3E%287%29%2C%203363%26%23x2013%3B3382.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Ftc-18-3363-2024%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Ftc-18-3363-2024%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Characterization%20of%20in%20situ%20cosmogenic%20%3Csup%3E14%3C%5C%2Fsup%3E%20CO%20production%2C%20retention%20and%20loss%20in%20firn%20and%20shallow%20ice%20at%20Summit%2C%20Greenland%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Benjamin%22%2C%22lastName%22%3A%22Hmiel%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Vasilii%20V.%22%2C%22lastName%22%3A%22Petrenko%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Christo%22%2C%22lastName%22%3A%22Buizert%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Andrew%20M.%22%2C%22lastName%22%3A%22Smith%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Michael%20N.%22%2C%22lastName%22%3A%22Dyonisius%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Philip%22%2C%22lastName%22%3A%22Place%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Bin%22%2C%22lastName%22%3A%22Yang%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Quan%22%2C%22lastName%22%3A%22Hua%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ross%22%2C%22lastName%22%3A%22Beaudette%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jeffrey%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Christina%22%2C%22lastName%22%3A%22Harth%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ray%20F.%22%2C%22lastName%22%3A%22Weiss%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Lindsey%22%2C%22lastName%22%3A%22Davidge%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Melisa%22%2C%22lastName%22%3A%22Diaz%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Matthew%22%2C%22lastName%22%3A%22Pacicco%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22James%20A.%22%2C%22lastName%22%3A%22Menking%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Michael%22%2C%22lastName%22%3A%22Kalk%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Xavier%22%2C%22lastName%22%3A%22Fa%5Cu00efn%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Alden%22%2C%22lastName%22%3A%22Adolph%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Isaac%22%2C%22lastName%22%3A%22Vimont%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Lee%20T.%22%2C%22lastName%22%3A%22Murray%22%7D%5D%2C%22abstractNote%22%3A%22Abstract.%20Measurements%20of%20carbon-14-containing%20carbon%20monoxide%20%2814CO%29%20in%20glacial%20ice%20are%20useful%20for%20studies%20of%20the%20past%20oxidative%20capacity%20of%20the%20atmosphere%20as%20well%20as%20for%20reconstructing%20the%20past%20cosmic%20ray%20flux.%20The%2014CO%20abundance%20in%20glacial%20ice%20represents%20the%20combination%20of%20trapped%20atmospheric%2014CO%20and%20in%20situ%20cosmogenic%2014CO.%20The%20systematics%20of%20in%20situ%20cosmogenic%2014CO%20production%20and%20retention%20in%20ice%20are%20not%20fully%20quantified%2C%20posing%20an%20obstacle%20to%20interpretation%20of%20ice%20core%2014CO%20measurements.%20Here%20we%20provide%20the%20first%20comprehensive%20characterization%20of%2014CO%20at%20an%20ice%20accumulation%20site%20%28Summit%2C%20Greenland%29%2C%20including%20measurements%20in%20the%20ice%20grains%20of%20the%20firn%20matrix%2C%20firn%20air%20and%20bubbly%20ice%20below%20the%20firn%20zone.%20The%20results%20are%20interpreted%20with%20the%20aid%20of%20a%20firn%20gas%20transport%20model%20into%20which%20we%20implemented%20in%20situ%20cosmogenic%2014C.%20We%20find%20that%20almost%20all%20%28%5Cu2248%5Cu200999.5%5Cu2009%25%29%20of%20in%20situ%2014CO%20that%20is%20produced%20in%20the%20ice%20grains%20in%20firn%20is%20very%20rapidly%20%28in%20%3C1%5Cu00a0year%29%20lost%20to%20the%20open%20porosity%20and%20from%20there%20mostly%20vented%20to%20the%20atmosphere.%20The%20timescale%20of%20this%20rapid%20loss%20is%20consistent%20with%20what%20is%20expected%20from%20gas%20diffusion%20through%20ice.%20The%20small%20fraction%20of%20in%20situ%2014CO%20that%20initially%20stays%20in%20the%20ice%20grains%20continues%20to%20slowly%20leak%20out%20to%20the%20open%20porosity%20at%20a%20rate%20of%20%5Cu2248%5Cu20090.6%5Cu2009%25%5Cu2009yr%5Cu22121.%20Below%20the%20firn%20zone%20we%20observe%20an%20increase%20in%2014CO%20content%20with%20depth%20that%20is%20due%20to%20in%20situ%2014CO%20production%20by%20deep-penetrating%20muons%2C%20confirming%20recent%20estimates%20of%2014CO%20production%20rates%20in%20ice%20via%20the%20muon%20mechanisms%20and%20allowing%20for%20narrowing%20constraints%20on%20these%20production%20rates.%22%2C%22date%22%3A%222024-07-25%22%2C%22language%22%3A%22en%22%2C%22DOI%22%3A%2210.5194%5C%2Ftc-18-3363-2024%22%2C%22ISSN%22%3A%221994-0424%22%2C%22url%22%3A%22https%3A%5C%2F%5C%2Ftc.copernicus.org%5C%2Farticles%5C%2F18%5C%2F3363%5C%2F2024%5C%2F%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%2C%225NFTUH6D%22%5D%2C%22dateModified%22%3A%222024-08-29T22%3A33%3A58Z%22%7D%7D%2C%7B%22key%22%3A%22G3TWH2JM%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Ng%20et%20al.%22%2C%22parsedDate%22%3A%222024-07-08%22%2C%22numChildren%22%3A0%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3ENg%2C%20J.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%2C%20Bay%2C%20R.%2C%20%26amp%3B%20Tosi%2C%20D.%20%282024%29.%20Evaluating%20marine%20dust%20records%20as%20templates%20for%20optical%20dating%20of%20Oldest%20Ice.%20%3Ci%3EClimate%20of%20the%20Past%3C%5C%2Fi%3E%2C%20%3Ci%3E20%3C%5C%2Fi%3E%287%29%2C%201437%26%23x2013%3B1449.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Fcp-20-1437-2024%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Fcp-20-1437-2024%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Evaluating%20marine%20dust%20records%20as%20templates%20for%20optical%20dating%20of%20Oldest%20Ice%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jessica%22%2C%22lastName%22%3A%22Ng%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jeffrey%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ryan%22%2C%22lastName%22%3A%22Bay%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Delia%22%2C%22lastName%22%3A%22Tosi%22%7D%5D%2C%22abstractNote%22%3A%22Abstract.%20The%20continuous%20ice%20core%20record%20extends%20800%5Cu2009000%5Cu00a0years%20into%20the%20past%2C%20covering%20the%20period%20of%20100%5Cu2009000-year%20glacial%20cycles%20but%20not%20the%20transition%20from%2040%5Cu2009000-year%20glacial%20cycles%20%28the%20mid-Pleistocene%20transition%2C%201.2%5Cu20130.7%5Cu00a0million%20years%20ago%29.%20A%20primary%20goal%20of%20the%20International%20Partnerships%20in%20Ice%20Core%20Sciences%20is%20therefore%20to%20retrieve%20a%201.5-million-year-old%20continuous%20ice%20core%2C%20increasing%20our%20understanding%20of%20this%20major%20change%20in%20the%20climate%20system%20and%20thus%20of%20fundamental%20climate%20forcings%20and%20feedbacks.%20However%2C%20complex%20glacial%20processes%2C%20limited%20bedrock%20data%2C%20and%20young%20basal%20ice%20in%20previous%20cores%20necessitate%20careful%20reconnaissance%20studies%20before%20extracting%20a%20full%20core.%20Ice%20borehole%20optical%20logging%20reflects%20the%20ice%20dust%20content%20and%20may%20be%20used%20to%20date%20ice%20quickly%20and%20inexpensively%20if%20a%20reference%20record%20is%20known.%20Here%20we%20explore%20the%20relationship%20between%20ice%20dust%20records%20and%20well-dated%20marine%20dust%20records%20from%20sediment%20cores%20in%20the%20southern%20Atlantic%20and%20Pacific%20oceans%2C%20which%20lie%20along%20paths%20of%20dust%20sources%20to%20Antarctica.%20We%20evaluate%20how%20representative%20these%20records%20are%20of%20Antarctic%20dust%20both%20through%20the%20existing%20ice%20core%20record%20and%20during%20the%20older%20target%20age%20range%2C%20suggesting%20that%20a%20newly%20published%201.5-million-year%20record%20from%20Site%20U1537%20near%20South%20America%20is%20likely%20the%20most%20robust%20predictor%20of%20the%20Oldest%20Ice%20dust%20signal.%20We%20then%20assess%20procedures%20for%20rapid%20dating%20of%20potential%20Oldest%20Ice%20sites%2C%20noting%20that%20the%20ability%20to%20detect%20dating%20errors%20is%20an%20essential%20feature.%20We%20emphasize%20that%20ongoing%20efforts%20to%20identify%2C%20recover%2C%20date%2C%20and%20interpret%20an%20Oldest%20Ice%20core%20should%20use%20care%20to%20avoid%20unfounded%20assumptions%20about%20the%2040%5Cu2009kyr%20world%20based%20on%20the%20100%5Cu2009kyr%20world.%22%2C%22date%22%3A%222024-07-08%22%2C%22language%22%3A%22en%22%2C%22DOI%22%3A%2210.5194%5C%2Fcp-20-1437-2024%22%2C%22ISSN%22%3A%221814-9332%22%2C%22url%22%3A%22https%3A%5C%2F%5C%2Fcp.copernicus.org%5C%2Farticles%5C%2F20%5C%2F1437%5C%2F2024%5C%2F%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222024-07-30T21%3A16%3A25Z%22%7D%7D%2C%7B%22key%22%3A%22CVLFP9IV%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Holliday%20et%20al.%22%2C%22parsedDate%22%3A%222024%22%2C%22numChildren%22%3A0%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EHolliday%2C%20Vance.%20T.%2C%20Daulton%2C%20T.%20L.%2C%20Bartlein%2C%20P.%20J.%2C%20Boslough%2C%20M.%20B.%2C%20Breslawski%2C%20R.%20P.%2C%20Fisher%2C%20A.%20E.%2C%20Jorgeson%2C%20I.%20A.%2C%20Scott%2C%20A.%20C.%2C%20Koeberl%2C%20C.%2C%20Marlon%2C%20J.%20R.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%2C%20Petaev%2C%20M.%20I.%2C%20%26amp%3B%20Claeys%2C%20P.%20%282024%29.%20Rebuttal%20of%20Sweatman%2C%20Powell%2C%20and%20West%26%23x2019%3Bs%20%26%23x201C%3BRejection%20of%20Holliday%20et%20al.%26%23x2019%3Bs%20alleged%20refutation%20of%20the%20Younger%20Dryas%20Impact%20Hypothesis.%26%23x201D%3B%20%3Ci%3EEarth-Science%20Reviews%3C%5C%2Fi%3E%2C%20%3Ci%3E258%3C%5C%2Fi%3E%2C%20104961.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1016%5C%2Fj.earscirev.2024.104961%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1016%5C%2Fj.earscirev.2024.104961%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Rebuttal%20of%20Sweatman%2C%20Powell%2C%20and%20West%27s%20%5Cu201cRejection%20of%20Holliday%20et%20al.%27s%20alleged%20refutation%20of%20the%20Younger%20Dryas%20Impact%20Hypothesis%5Cu201d%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Vance.T.%22%2C%22lastName%22%3A%22Holliday%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Tyrone%20L.%22%2C%22lastName%22%3A%22Daulton%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Patrick%20J.%22%2C%22lastName%22%3A%22Bartlein%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Mark%20B.%22%2C%22lastName%22%3A%22Boslough%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ryan%20P.%22%2C%22lastName%22%3A%22Breslawski%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Abigail%20E.%22%2C%22lastName%22%3A%22Fisher%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ian%20A.%22%2C%22lastName%22%3A%22Jorgeson%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Andrew%20C.%22%2C%22lastName%22%3A%22Scott%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Christian%22%2C%22lastName%22%3A%22Koeberl%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jennifer%20R.%22%2C%22lastName%22%3A%22Marlon%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jeffrey%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Michail%20I.%22%2C%22lastName%22%3A%22Petaev%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Philippe%22%2C%22lastName%22%3A%22Claeys%22%7D%5D%2C%22abstractNote%22%3A%22%22%2C%22date%22%3A%2211%5C%2F2024%22%2C%22language%22%3A%22en%22%2C%22DOI%22%3A%2210.1016%5C%2Fj.earscirev.2024.104961%22%2C%22ISSN%22%3A%2200128252%22%2C%22url%22%3A%22https%3A%5C%2F%5C%2Flinkinghub.elsevier.com%5C%2Fretrieve%5C%2Fpii%5C%2FS0012825224002897%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222024-12-23T17%3A42%3A11Z%22%7D%7D%2C%7B%22key%22%3A%22HFQKB98W%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Patterson%20et%20al.%22%2C%22parsedDate%22%3A%222023-12-12%22%2C%22numChildren%22%3A0%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EPatterson%2C%20J.%20D.%2C%20Aydin%2C%20M.%2C%20Crotwell%2C%20A.%20M.%2C%20P%26%23xE9%3Btron%2C%20G.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20Krummel%2C%20P.%20B.%2C%20Langenfelds%2C%20R.%20L.%2C%20Petrenko%2C%20V.%20V.%2C%20%26amp%3B%20Saltzman%2C%20E.%20S.%20%282023%29.%20Reconstructing%20atmospheric%20H%20%3Csub%3E2%3C%5C%2Fsub%3E%20over%20the%20past%20century%20from%20bi-polar%20firn%20air%20records.%20%3Ci%3EClimate%20of%20the%20Past%3C%5C%2Fi%3E%2C%20%3Ci%3E19%3C%5C%2Fi%3E%2812%29%2C%202535%26%23x2013%3B2550.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Fcp-19-2535-2023%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Fcp-19-2535-2023%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Reconstructing%20atmospheric%20H%20%3Csub%3E2%3C%5C%2Fsub%3E%20over%20the%20past%20century%20from%20bi-polar%20firn%20air%20records%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22John%20D.%22%2C%22lastName%22%3A%22Patterson%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Murat%22%2C%22lastName%22%3A%22Aydin%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Andrew%20M.%22%2C%22lastName%22%3A%22Crotwell%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Gabrielle%22%2C%22lastName%22%3A%22P%5Cu00e9tron%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jeffery%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Paul%20B.%22%2C%22lastName%22%3A%22Krummel%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ray%20L.%22%2C%22lastName%22%3A%22Langenfelds%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Vasilii%20V.%22%2C%22lastName%22%3A%22Petrenko%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Eric%20S.%22%2C%22lastName%22%3A%22Saltzman%22%7D%5D%2C%22abstractNote%22%3A%22Abstract.%20Historical%20atmospheric%20H2%20levels%20were%20reconstructed%20using%20firn%20air%20measurements%20from%20two%20sites%20in%20Greenland%20%28NEEM%20and%20Summit%29%20and%20two%20sites%20in%20Antarctica%20%28South%20Pole%20and%20Megadunes%29.%20A%20joint%20reconstruction%20based%20on%20the%20two%20Antarctic%20sites%20yields%20H2%20levels%20monotonically%20increasing%20from%20about%20330%5Cu2009ppb%20in%201900%20to%20550%5Cu2009ppb%20in%20the%20late%201990s%2C%20leveling%20off%20thereafter.%20These%20results%20are%20similar%20to%20individual%20reconstructions%20published%20previously%20%28Patterson%20et%20al.%2C%202020%2C%202021%29.%20Interpretation%20of%20the%20Greenland%20firn%20air%20measurements%20is%20complicated%20by%20challenges%20in%20modeling%20enrichment%20induced%20by%20pore%20close-off%20at%20these%20sites.%20We%20used%20observations%20of%20neon%20enrichment%20at%20NEEM%20and%20Summit%20to%20tune%20the%20parameterization%20of%20enrichment%20induced%20by%20pore%20close-off%20in%20our%20firn%20air%20model.%20The%20joint%20reconstruction%20from%20the%20Greenland%20data%20shows%20H2%20levels%20rising%2030%5Cu2009%25%20between%201950%20and%20the%20late%201980s%2C%20reaching%20a%20maximum%20of%20530%5Cu2009ppb.%20After%201990%2C%20reconstructed%20atmospheric%20H2%20levels%20over%20Greenland%20are%20roughly%20constant%2C%20with%20a%20small%20decline%20of%203%5Cu2009%25%20over%20the%20next%2025%5Cu00a0years.%20The%20reconstruction%20shows%20good%20agreement%20with%20the%20available%20flask%20measurements%20of%20H2%20at%20high%20northern%20latitudes.%22%2C%22date%22%3A%222023-12-12%22%2C%22language%22%3A%22en%22%2C%22DOI%22%3A%2210.5194%5C%2Fcp-19-2535-2023%22%2C%22ISSN%22%3A%221814-9332%22%2C%22url%22%3A%22https%3A%5C%2F%5C%2Fcp.copernicus.org%5C%2Farticles%5C%2F19%5C%2F2535%5C%2F2023%5C%2F%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222024-03-22T16%3A51%3A47Z%22%7D%7D%2C%7B%22key%22%3A%2296EQVMV6%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Epifanio%20et%20al.%22%2C%22parsedDate%22%3A%222023-11-15%22%2C%22numChildren%22%3A0%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EEpifanio%2C%20J.%20A.%2C%20Brook%2C%20E.%20J.%2C%20Buizert%2C%20C.%2C%20Pettit%2C%20E.%20C.%2C%20Edwards%2C%20J.%20S.%2C%20Fegyveresi%2C%20J.%20M.%2C%20Sowers%2C%20T.%20A.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20%26amp%3B%20Kahle%2C%20E.%20C.%20%282023%29.%20Millennial%20and%20orbital-scale%20variability%20in%20a%2054%20000-year%20record%20of%20total%20air%20content%20from%20the%20South%20Pole%20ice%20core.%20%3Ci%3EThe%20Cryosphere%3C%5C%2Fi%3E%2C%20%3Ci%3E17%3C%5C%2Fi%3E%2811%29%2C%204837%26%23x2013%3B4851.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Ftc-17-4837-2023%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Ftc-17-4837-2023%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Millennial%20and%20orbital-scale%20variability%20in%20a%2054%20000-year%20record%20of%20total%20air%20content%20from%20the%20South%20Pole%20ice%20core%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jenna%20A.%22%2C%22lastName%22%3A%22Epifanio%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Edward%20J.%22%2C%22lastName%22%3A%22Brook%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Christo%22%2C%22lastName%22%3A%22Buizert%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Erin%20C.%22%2C%22lastName%22%3A%22Pettit%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jon%20S.%22%2C%22lastName%22%3A%22Edwards%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22John%20M.%22%2C%22lastName%22%3A%22Fegyveresi%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Todd%20A.%22%2C%22lastName%22%3A%22Sowers%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jeffrey%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Emma%20C.%22%2C%22lastName%22%3A%22Kahle%22%7D%5D%2C%22abstractNote%22%3A%22Abstract.%20The%20total%20air%20content%20%28TAC%29%20of%20polar%20ice%20cores%20has%20long%20been%20considered%20a%20potential%20proxy%20for%20past%20ice%20sheet%20elevation.%20Recent%20work%2C%20however%2C%20has%20shown%20that%20a%20variety%20of%20other%20factors%20also%20influence%20this%20parameter.%20In%20this%20paper%20we%20present%20a%20high-resolution%20TAC%20record%20from%20the%20South%20Pole%20ice%20core%20%28SPC14%29%20covering%20the%20last%2054%5Cu2009000%5Cu00a0years%20and%20discuss%20the%20implications%20of%20the%20data%20for%20interpreting%20TAC%20from%20ice%20cores.%20The%20SPC14%20TAC%20record%20shows%20multiple%20features%20of%20interest%2C%20including%20%281%29%5Cu00a0long-term%20orbital-scale%20variability%2C%20%282%29%5Cu00a0millennial-scale%20variability%20in%20the%20Holocene%20and%20last%20glacial%20period%2C%20and%20%283%29%5Cu00a0a%20period%20of%20stability%20from%2035%20to%2025%5Cu2009ka.%20The%20longer%2C%20orbital-scale%20variations%20in%20TAC%20are%20highly%20correlated%20with%20integrated%20summer%20insolation%20%28ISI%29%2C%20corroborating%20the%20potential%20of%20TAC%20to%20provide%20an%20independent%20dating%20tool%20via%20orbital%20tuning.%20Large%20millennial-scale%20variability%20in%20TAC%20during%20the%20last%20glacial%20period%20is%20positively%20correlated%20with%20past%20accumulation%20rate%20reconstructions%20as%20well%20as%20%5Cu03b415N-N2%2C%20a%20firn%20thickness%20proxy.%20These%20TAC%20variations%20are%20too%20large%20to%20be%20controlled%20by%20direct%20effects%20of%20temperature%20and%20too%20rapid%20to%20be%20tied%20to%20elevation%20changes.%20We%20propose%20that%20grain%20size%20metamorphism%20near%20the%20firn%20surface%20explains%20these%20changes.%20We%20note%2C%20however%2C%20that%20at%20sites%20with%20different%20climate%20histories%20than%20the%20South%20Pole%2C%20TAC%20variations%20may%20be%20dominated%20by%20other%20processes.%20Our%20observations%20of%20millennial-scale%20variations%20in%20TAC%20show%20a%20different%20relationship%20with%20accumulation%20rate%20than%20observed%20at%20sites%20in%20Greenland.%22%2C%22date%22%3A%222023-11-15%22%2C%22language%22%3A%22en%22%2C%22DOI%22%3A%2210.5194%5C%2Ftc-17-4837-2023%22%2C%22ISSN%22%3A%221994-0424%22%2C%22url%22%3A%22https%3A%5C%2F%5C%2Ftc.copernicus.org%5C%2Farticles%5C%2F17%5C%2F4837%5C%2F2023%5C%2F%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222024-03-22T16%3A30%3A16Z%22%7D%7D%2C%7B%22key%22%3A%22VUHFHZSF%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Venugopal%20et%20al.%22%2C%22parsedDate%22%3A%222023-09-05%22%2C%22numChildren%22%3A0%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EVenugopal%2C%20A.%20U.%2C%20Bertler%2C%20N.%20A.%20N.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20Brook%2C%20E.%20J.%2C%20Cortese%2C%20G.%2C%20Lee%2C%20J.%20E.%2C%20Blunier%2C%20T.%2C%20Mayewski%2C%20P.%20A.%2C%20Kj%26%23xE6%3Br%2C%20H.%20A.%2C%20Carter%2C%20L.%2C%20Weber%2C%20M.%20E.%2C%20Levy%2C%20R.%20H.%2C%20Pyne%2C%20R.%20L.%2C%20%26amp%3B%20Vandergoes%2C%20M.%20J.%20%282023%29.%20Antarctic%20evidence%20for%20an%20abrupt%20northward%20shift%20of%20the%20Southern%20Hemisphere%20westerlies%20at%2032%20ka%20BP.%20%3Ci%3ENature%20Communications%3C%5C%2Fi%3E%2C%20%3Ci%3E14%3C%5C%2Fi%3E%281%29%2C%205432.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1038%5C%2Fs41467-023-40951-1%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1038%5C%2Fs41467-023-40951-1%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Antarctic%20evidence%20for%20an%20abrupt%20northward%20shift%20of%20the%20Southern%20Hemisphere%20westerlies%20at%2032%20ka%20BP%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Abhijith%20U.%22%2C%22lastName%22%3A%22Venugopal%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Nancy%20A.%20N.%22%2C%22lastName%22%3A%22Bertler%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jeffrey%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Edward%20J.%22%2C%22lastName%22%3A%22Brook%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Giuseppe%22%2C%22lastName%22%3A%22Cortese%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22James%20E.%22%2C%22lastName%22%3A%22Lee%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Thomas%22%2C%22lastName%22%3A%22Blunier%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Paul%20A.%22%2C%22lastName%22%3A%22Mayewski%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Helle%20A.%22%2C%22lastName%22%3A%22Kj%5Cu00e6r%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Lionel%22%2C%22lastName%22%3A%22Carter%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Michael%20E.%22%2C%22lastName%22%3A%22Weber%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Richard%20H.%22%2C%22lastName%22%3A%22Levy%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Rebecca%20L.%22%2C%22lastName%22%3A%22Pyne%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Marcus%20J.%22%2C%22lastName%22%3A%22Vandergoes%22%7D%5D%2C%22abstractNote%22%3A%22Abstract%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20High-resolution%20ice%20core%20records%20from%20coastal%20Antarctica%20are%20particularly%20useful%20to%20inform%20our%20understanding%20of%20environmental%20changes%20and%20their%20drivers.%20Here%2C%20we%20present%20a%20decadally%20resolved%20record%20of%20sea-salt%20sodium%20%28a%20proxy%20for%20open-ocean%20area%29%20and%20non-sea%20salt%20calcium%20%28a%20proxy%20for%20continental%20dust%29%20from%20the%20well-dated%20Roosevelt%20Island%20Climate%20Evolution%20%28RICE%29%20core%2C%20focusing%20on%5Cu00a0the%20time%20period%20between%2040%5Cu201326%5Cu2009ka%20BP.%20The%20RICE%20dust%20record%20exhibits%20an%20abrupt%20shift%20towards%20a%20higher%20mean%20dust%20concentration%20at%2032%5Cu2009ka%20BP.%20Investigating%20existing%20ice-core%20records%2C%20we%20find%20this%20shift%20is%20a%20prominent%20feature%20across%20Antarctica.%20We%20propose%20that%20this%20shift%20is%20linked%20to%20an%20equatorward%20displacement%20of%20Southern%20Hemisphere%20westerly%20winds.%20Subsequent%20to%20the%20wind%20shift%2C%20data%20suggest%20a%20weakening%20of%20Southern%20Ocean%20upwelling%20and%20a%20decline%20of%20atmospheric%20CO%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%202%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20to%20lower%20glacial%20values%2C%20hence%20making%20this%20shift%20an%20important%20glacial%20climate%20event%20with%20potentially%20important%20insights%20for%20future%20projections.%22%2C%22date%22%3A%222023-09-05%22%2C%22language%22%3A%22en%22%2C%22DOI%22%3A%2210.1038%5C%2Fs41467-023-40951-1%22%2C%22ISSN%22%3A%222041-1723%22%2C%22url%22%3A%22https%3A%5C%2F%5C%2Fwww.nature.com%5C%2Farticles%5C%2Fs41467-023-40951-1%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222023-10-20T17%3A42%3A11Z%22%7D%7D%2C%7B%22key%22%3A%222GMGXBKE%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Martin%20et%20al.%22%2C%22parsedDate%22%3A%222023-05-04%22%2C%22numChildren%22%3A0%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EMartin%2C%20K.%20C.%2C%20Buizert%2C%20C.%2C%20Edwards%2C%20J.%20S.%2C%20Kalk%2C%20M.%20L.%2C%20Riddell-Young%2C%20B.%2C%20Brook%2C%20E.%20J.%2C%20Beaudette%2C%20R.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20%26amp%3B%20Sowers%2C%20T.%20A.%20%282023%29.%20Bipolar%20impact%20and%20phasing%20of%20Heinrich-type%20climate%20variability.%20%3Ci%3ENature%3C%5C%2Fi%3E%2C%20%3Ci%3E617%3C%5C%2Fi%3E%287959%29%2C%20100%26%23x2013%3B104.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1038%5C%2Fs41586-023-05875-2%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1038%5C%2Fs41586-023-05875-2%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Bipolar%20impact%20and%20phasing%20of%20Heinrich-type%20climate%20variability%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Kaden%20C.%22%2C%22lastName%22%3A%22Martin%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Christo%22%2C%22lastName%22%3A%22Buizert%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jon%20S.%22%2C%22lastName%22%3A%22Edwards%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Michael%20L.%22%2C%22lastName%22%3A%22Kalk%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ben%22%2C%22lastName%22%3A%22Riddell-Young%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Edward%20J.%22%2C%22lastName%22%3A%22Brook%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ross%22%2C%22lastName%22%3A%22Beaudette%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jeffrey%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Todd%20A.%22%2C%22lastName%22%3A%22Sowers%22%7D%5D%2C%22abstractNote%22%3A%22%22%2C%22date%22%3A%222023-05-04%22%2C%22language%22%3A%22en%22%2C%22DOI%22%3A%2210.1038%5C%2Fs41586-023-05875-2%22%2C%22ISSN%22%3A%220028-0836%2C%201476-4687%22%2C%22url%22%3A%22https%3A%5C%2F%5C%2Fwww.nature.com%5C%2Farticles%5C%2Fs41586-023-05875-2%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222023-05-22T23%3A42%3A20Z%22%7D%7D%2C%7B%22key%22%3A%22DNY46WBZ%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Ng%20et%20al.%22%2C%22parsedDate%22%3A%222023-04-15%22%2C%22numChildren%22%3A0%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3ENg%2C%20J.%2C%20Tyne%2C%20R.%2C%20Seltzer%2C%20A.%2C%20Noyes%2C%20C.%2C%20McIntosh%2C%20J.%2C%20%26amp%3B%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20%282023%29.%20A%20new%20large%26%23x2010%3Bvolume%20equilibration%20method%20for%20high%26%23x2010%3Bprecision%20measurements%20of%20dissolved%20noble%20gas%20stable%20isotopes.%20%3Ci%3ERapid%20Communications%20in%20Mass%20Spectrometry%3C%5C%2Fi%3E%2C%20%3Ci%3E37%3C%5C%2Fi%3E%287%29.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1002%5C%2Frcm.9471%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1002%5C%2Frcm.9471%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22A%20new%20large%5Cu2010volume%20equilibration%20method%20for%20high%5Cu2010precision%20measurements%20of%20dissolved%20noble%20gas%20stable%20isotopes%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jessica%22%2C%22lastName%22%3A%22Ng%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Rebecca%22%2C%22lastName%22%3A%22Tyne%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Alan%22%2C%22lastName%22%3A%22Seltzer%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Chandler%22%2C%22lastName%22%3A%22Noyes%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jennifer%22%2C%22lastName%22%3A%22McIntosh%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jeffrey%22%2C%22lastName%22%3A%22Severinghaus%22%7D%5D%2C%22abstractNote%22%3A%22%22%2C%22date%22%3A%222023-04-15%22%2C%22language%22%3A%22en%22%2C%22DOI%22%3A%2210.1002%5C%2Frcm.9471%22%2C%22ISSN%22%3A%220951-4198%2C%201097-0231%22%2C%22url%22%3A%22https%3A%5C%2F%5C%2Fonlinelibrary.wiley.com%5C%2Fdoi%5C%2F10.1002%5C%2Frcm.9471%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222023-02-17T00%3A25%3A43Z%22%7D%7D%2C%7B%22key%22%3A%22DDKKF6IR%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Buizert%20et%20al.%22%2C%22parsedDate%22%3A%222023-03-15%22%2C%22numChildren%22%3A0%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EBuizert%2C%20C.%2C%20Shackleton%2C%20S.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20Roberts%2C%20W.%20H.%20G.%2C%20Seltzer%2C%20A.%2C%20Bereiter%2C%20B.%2C%20Kawamura%2C%20K.%2C%20Baggenstos%2C%20D.%2C%20Orsi%2C%20A.%20J.%2C%20Oyabu%2C%20I.%2C%20Birner%2C%20B.%2C%20Morgan%2C%20J.%20D.%2C%20Brook%2C%20E.%20J.%2C%20Etheridge%2C%20D.%20M.%2C%20Thornton%2C%20D.%2C%20Bertler%2C%20N.%2C%20Pyne%2C%20R.%20L.%2C%20Mulvaney%2C%20R.%2C%20Mosley-Thompson%2C%20E.%2C%20%26%23x2026%3B%20Petrenko%2C%20V.%20V.%20%282023%29.%20The%20new%20Kr-86%20excess%20ice%20core%20proxy%20for%20synoptic%20activity%3A%20West%20Antarctic%20storminess%20possibly%20linked%20to%20Intertropical%20Convergence%20Zone%20%28ITCZ%29%20movement%20through%20the%20last%20deglaciation.%20%3Ci%3EClimate%20of%20the%20Past%3C%5C%2Fi%3E%2C%20%3Ci%3E19%3C%5C%2Fi%3E%283%29%2C%20579%26%23x2013%3B606.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Fcp-19-579-2023%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Fcp-19-579-2023%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22The%20new%20Kr-86%20excess%20ice%20core%20proxy%20for%20synoptic%20activity%3A%20West%20Antarctic%20storminess%20possibly%20linked%20to%20Intertropical%20Convergence%20Zone%20%28ITCZ%29%20movement%20through%20the%20last%20deglaciation%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Christo%22%2C%22lastName%22%3A%22Buizert%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Sarah%22%2C%22lastName%22%3A%22Shackleton%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jeffrey%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22William%20H.%20G.%22%2C%22lastName%22%3A%22Roberts%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Alan%22%2C%22lastName%22%3A%22Seltzer%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Bernhard%22%2C%22lastName%22%3A%22Bereiter%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Kenji%22%2C%22lastName%22%3A%22Kawamura%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Daniel%22%2C%22lastName%22%3A%22Baggenstos%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ana%5Cu00efs%20J.%22%2C%22lastName%22%3A%22Orsi%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ikumi%22%2C%22lastName%22%3A%22Oyabu%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Benjamin%22%2C%22lastName%22%3A%22Birner%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jacob%20D.%22%2C%22lastName%22%3A%22Morgan%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Edward%20J.%22%2C%22lastName%22%3A%22Brook%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22David%20M.%22%2C%22lastName%22%3A%22Etheridge%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22David%22%2C%22lastName%22%3A%22Thornton%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Nancy%22%2C%22lastName%22%3A%22Bertler%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Rebecca%20L.%22%2C%22lastName%22%3A%22Pyne%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Robert%22%2C%22lastName%22%3A%22Mulvaney%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ellen%22%2C%22lastName%22%3A%22Mosley-Thompson%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Peter%20D.%22%2C%22lastName%22%3A%22Neff%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Vasilii%20V.%22%2C%22lastName%22%3A%22Petrenko%22%7D%5D%2C%22abstractNote%22%3A%22Abstract.%20Here%20we%20present%20a%20newly%20developed%20ice%20core%20gas-phase%20proxy%20that%20directly%5Cnsamples%20a%20component%20of%20the%20large-scale%20atmospheric%20circulation%3A%5Cnsynoptic-scale%20pressure%20variability.%20Surface%20pressure%20changes%20weakly%20disrupt%20gravitational%20isotopic%20settling%20in%20the%20firn%20layer%2C%20which%20is%20recorded%20in%20krypton-86%20excess%5Cu00a0%2886Krxs%29.%20The%2086Krxs%20may%20therefore%20reflect%20the%20time-averaged%20synoptic%20pressure%20variability%20over%20several%20years%20%28site%20%5Cu201cstorminess%5Cu201d%29%2C%20but%20it%20likely%20cannot%20record%20individual%20synoptic%20events%20as%20ice%20core%20gas%20samples%20typically%20average%20over%20several%20years.%20We%20validate%2086Krxs%20using%20late%20Holocene%20ice%20samples%20from%2011%20Antarctic%20ice%20cores%20and%201%20Greenland%20ice%20core%20that%20collectively%20represent%20a%20wide%20range%20of%20surface%20pressure%20variability%20in%20the%20modern%20climate.%20We%20find%20a%20strong%20spatial%20correlation%20%28r%3D-0.94%2C%20p%3C0.01%29%20between%20site%20average%2086Krxs%20and%20time-averaged%20synoptic%20variability%20from%20reanalysis%20data.%20The%20main%20uncertainties%20in%20the%20analysis%20are%20the%20corrections%20for%20gas%20loss%20and%20thermal%20fractionation%20and%20the%20relatively%20large%20scatter%20in%20the%20data.%20Limited%20scientific%20understanding%20of%20the%20firn%20physics%20and%20potential%20biases%20of%2086Krxs%20require%20caution%20in%20interpreting%20this%20proxy%20at%20present.%20We%20show%20that%20Antarctic%2086Krxs%20appears%20to%20be%20linked%20to%20the%20position%20of%20the%20Southern%20Hemisphere%20eddy-driven%20subpolar%20jet%5Cu00a0%28SPJ%29%2C%20with%20a%20southern%20position%20enhancing%20pressure%20variability.%20We%20present%20a%2086Krxs%20record%20covering%20the%20last%2024%5Cu2009kyr%20from%20the%20West%20Antarctic%20Ice%20Sheet%20%28WAIS%29%20Divide%20ice%20core.%20Based%20on%20the%20empirical%20spatial%20correlation%20of%20synoptic%20activity%20and%2086Krxs%20at%20various%20Antarctic%20sites%2C%20we%20interpret%20this%20record%20to%20show%20that%20West%20Antarctic%20synoptic%20activity%20is%20slightly%20below%20modern%20levels%20during%20the%20Last%20Glacial%20Maximum%5Cu00a0%28LGM%29%2C%20increases%20during%20the%20Heinrich%20Stadial%5Cu00a01%20and%20Younger%20Dryas%20North%20Atlantic%20cold%20periods%2C%20weakens%20abruptly%20at%20the%20Holocene%20onset%2C%20remains%20low%20during%20the%20early%20and%20mid-Holocene%2C%20and%20gradually%20increases%20to%20its%20modern%20value.%20The%20WAIS%20Divide%2086Krxs%20record%20resembles%20records%20of%20monsoon%20intensity%20thought%20to%20reflect%20changes%20in%20the%20meridional%20position%20of%20the%20Intertropical%20Convergence%20Zone%5Cu00a0%28ITCZ%29%20on%20orbital%20and%20millennial%20timescales%20such%20that%20West%20Antarctic%20storminess%20is%20weaker%20when%20the%20ITCZ%20is%20displaced%20northward%20and%20stronger%20when%20it%20is%20displaced%20southward.%20We%20interpret%20variations%20in%20synoptic%20activity%20as%20reflecting%20movement%20of%20the%20South%20Pacific%20SPJ%20in%20parallel%20to%20the%20ITCZ%20migrations%2C%20which%20is%20the%20expected%20zonal%20mean%20response%20of%20the%20eddy-driven%20jet%20in%20models%20and%20proxy%20data.%20Past%20changes%20to%20Pacific%20climate%20and%20the%20El%5Cu00a0Ni%5Cu00f1o%5Cu2013Southern%20Oscillation%20%28ENSO%29%20may%20amplify%20the%20signal%20of%20the%20SPJ%20migration.%20Our%20interpretation%20is%20broadly%20consistent%20with%20opal%20flux%20records%20from%20the%20Pacific%20Antarctic%20zone%20thought%20to%20reflect%20wind-driven%20upwelling.%20We%20emphasize%20that%2086Krxs%20is%20a%20new%20proxy%2C%20and%20more%20work%20is%20called%20for%20to%20confirm%2C%20replicate%2C%20and%20better%20understand%20these%20results%3B%20until%20such%20time%2C%20our%20conclusions%20regarding%20past%20atmospheric%20dynamics%20remain%5Cnspeculative.%20Current%20scientific%20understanding%20of%20firn%20air%20transport%20and%5Cntrapping%20is%20insufficient%20to%20explain%20all%20the%20observed%20variations%20in%5Cn86Krxs.%20A%20list%20of%20suggested%20future%20studies%20is%20provided.%22%2C%22date%22%3A%222023-03-15%22%2C%22language%22%3A%22en%22%2C%22DOI%22%3A%2210.5194%5C%2Fcp-19-579-2023%22%2C%22ISSN%22%3A%221814-9332%22%2C%22url%22%3A%22https%3A%5C%2F%5C%2Fcp.copernicus.org%5C%2Farticles%5C%2F19%5C%2F579%5C%2F2023%5C%2F%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222023-04-17T22%3A27%3A04Z%22%7D%7D%2C%7B%22key%22%3A%22TBIZC4EJ%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Dyonisius%20et%20al.%22%2C%22parsedDate%22%3A%222023-02-20%22%2C%22numChildren%22%3A0%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EDyonisius%2C%20M.%20N.%2C%20Petrenko%2C%20V.%20V.%2C%20Smith%2C%20A.%20M.%2C%20Hmiel%2C%20B.%2C%20Neff%2C%20P.%20D.%2C%20Yang%2C%20B.%2C%20Hua%2C%20Q.%2C%20Schmitt%2C%20J.%2C%20Shackleton%2C%20S.%20A.%2C%20Buizert%2C%20C.%2C%20Place%2C%20P.%20F.%2C%20Menking%2C%20J.%20A.%2C%20Beaudette%2C%20R.%2C%20Harth%2C%20C.%2C%20Kalk%2C%20M.%2C%20Roop%2C%20H.%20A.%2C%20Bereiter%2C%20B.%2C%20Armanetti%2C%20C.%2C%20Vimont%2C%20I.%2C%20%26%23x2026%3B%20McConnell%2C%20J.%20R.%20%282023%29.%20Using%20ice%20core%20measurements%20from%20Taylor%20Glacier%2C%20Antarctica%2C%20to%20calibrate%20in%20situ%20cosmogenic%20%3Csup%3E14%3C%5C%2Fsup%3E%20C%20production%20rates%20by%20muons.%20%3Ci%3EThe%20Cryosphere%3C%5C%2Fi%3E%2C%20%3Ci%3E17%3C%5C%2Fi%3E%282%29%2C%20843%26%23x2013%3B863.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Ftc-17-843-2023%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Ftc-17-843-2023%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Using%20ice%20core%20measurements%20from%20Taylor%20Glacier%2C%20Antarctica%2C%20to%20calibrate%20in%20situ%20cosmogenic%20%3Csup%3E14%3C%5C%2Fsup%3E%20C%20production%20rates%20by%20muons%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Michael%20N.%22%2C%22lastName%22%3A%22Dyonisius%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Vasilii%20V.%22%2C%22lastName%22%3A%22Petrenko%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Andrew%20M.%22%2C%22lastName%22%3A%22Smith%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Benjamin%22%2C%22lastName%22%3A%22Hmiel%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Peter%20D.%22%2C%22lastName%22%3A%22Neff%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Bin%22%2C%22lastName%22%3A%22Yang%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Quan%22%2C%22lastName%22%3A%22Hua%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jochen%22%2C%22lastName%22%3A%22Schmitt%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Sarah%20A.%22%2C%22lastName%22%3A%22Shackleton%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Christo%22%2C%22lastName%22%3A%22Buizert%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Philip%20F.%22%2C%22lastName%22%3A%22Place%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22James%20A.%22%2C%22lastName%22%3A%22Menking%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ross%22%2C%22lastName%22%3A%22Beaudette%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Christina%22%2C%22lastName%22%3A%22Harth%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Michael%22%2C%22lastName%22%3A%22Kalk%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Heidi%20A.%22%2C%22lastName%22%3A%22Roop%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Bernhard%22%2C%22lastName%22%3A%22Bereiter%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Casey%22%2C%22lastName%22%3A%22Armanetti%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Isaac%22%2C%22lastName%22%3A%22Vimont%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Sylvia%22%2C%22lastName%22%3A%22Englund%20Michel%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Edward%20J.%22%2C%22lastName%22%3A%22Brook%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jeffrey%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ray%20F.%22%2C%22lastName%22%3A%22Weiss%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Joseph%20R.%22%2C%22lastName%22%3A%22McConnell%22%7D%5D%2C%22abstractNote%22%3A%22Abstract.%20Cosmic%20rays%20entering%20the%20Earth%27s%20atmosphere%20produce%20showers%20of%20secondary%20particles%20such%20as%20protons%2C%20neutrons%2C%20and%20muons.%20The%20interaction%20of%20these%20particles%20with%20oxygen-16%20%2816O%29%20in%20minerals%20such%20as%20ice%20and%20quartz%20can%20produce%20carbon-14%20%2814C%29.%20In%20glacial%20ice%2C%2014C%20is%20also%20incorporated%20through%20trapping%20of%2014C-containing%20atmospheric%20gases%20%2814CO2%2C%2014CO%2C%20and%2014CH4%29.%20Understanding%20the%20production%20rates%20of%20in%20situ%20cosmogenic%2014C%20is%20important%20to%20deconvolve%20the%20in%20situ%20cosmogenic%20and%20atmospheric%2014C%20signals%20in%20ice%2C%20both%20of%20which%20contain%20valuable%20paleoenvironmental%20information.%20Unfortunately%2C%20the%20in%20situ%2014C%20production%20rates%20by%20muons%20%28which%20are%20the%20dominant%20production%20mechanism%20at%20depths%20of%20%3E6%5Cu2009m%20solid%20ice%20equivalent%29%20are%20uncertain.%20In%20this%20study%2C%20we%20use%20measurements%20of%20in%20situ%2014C%20in%20ancient%20ice%20%28%3E50%5Cu2009ka%29%20from%20the%20Taylor%20Glacier%2C%20an%20ablation%20site%20in%20Antarctica%2C%20in%20combination%20with%20a%202D%20ice%20flow%20model%20to%20better%20constrain%20the%20compound-specific%20rates%20of%2014C%20production%20by%20muons%20and%20the%20partitioning%20of%20in%20situ%2014C%20between%20CO2%2C%20CO%2C%20and%20CH4.%20Our%20measurements%20show%20that%2033.7%5Cu2009%25%20%28%5Cu00b111.4%5Cu2009%25%3B%2095%5Cu2009%25%20confidence%20interval%29%20of%20the%20produced%20cosmogenic%2014C%20forms%2014CO%20and%2066.1%5Cu2009%25%20%28%5Cu00b111.5%5Cu2009%25%3B%2095%5Cu2009%25%20confidence%20interval%29%20of%20the%20produced%20cosmogenic%2014C%20forms%2014CO2.%2014CH4%20represents%20a%20very%20small%20fraction%20%28%3C0.3%5Cu2009%25%29%20of%20the%20total.%20Assuming%20that%20the%20majority%20of%20in%20situ%20muogenic%2014C%20in%20ice%20forms%2014CO2%2C%2014CO%2C%20and%2014CH4%2C%20we%20also%20calculated%20muogenic%2014C%20production%20rates%20that%20are%20lower%20by%20factors%20of%205.7%20%283.6%5Cu201313.9%3B%2095%5Cu2009%25%20confidence%20interval%29%20and%203.7%20%282.0%5Cu201311.9%3B%2095%5Cu2009%25%20confidence%20interval%29%20for%20negative%20muon%20capture%20and%20fast%20muon%20interactions%2C%20respectively%2C%20when%20compared%20to%20values%20determined%20in%20quartz%20from%20laboratory%20studies%20%28Heisinger%20et%20al.%2C%202002a%2C%20b%29%20and%20in%20a%20natural%20setting%20%28Lupker%20et%20al.%2C%202015%29.%20This%20apparent%20discrepancy%20in%20muogenic%2014C%20production%20rates%20in%20ice%20and%20quartz%20currently%20lacks%20a%20good%20explanation%20and%20requires%20further%20investigation.%22%2C%22date%22%3A%222023-02-20%22%2C%22language%22%3A%22en%22%2C%22DOI%22%3A%2210.5194%5C%2Ftc-17-843-2023%22%2C%22ISSN%22%3A%221994-0424%22%2C%22url%22%3A%22https%3A%5C%2F%5C%2Ftc.copernicus.org%5C%2Farticles%5C%2F17%5C%2F843%5C%2F2023%5C%2F%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%2C%225NFTUH6D%22%5D%2C%22dateModified%22%3A%222023-04-17T22%3A33%3A52Z%22%7D%7D%2C%7B%22key%22%3A%22ZQDARFGT%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Holliday%20et%20al.%22%2C%22parsedDate%22%3A%222023%22%2C%22numChildren%22%3A0%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EHolliday%2C%20V.%20T.%2C%20Daulton%2C%20T.%20L.%2C%20Bartlein%2C%20P.%20J.%2C%20Boslough%2C%20M.%20B.%2C%20Breslawski%2C%20R.%20P.%2C%20Fisher%2C%20A.%20E.%2C%20Jorgeson%2C%20I.%20A.%2C%20Scott%2C%20A.%20C.%2C%20Koeberl%2C%20C.%2C%20Marlon%2C%20J.%20R.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%2C%20Petaev%2C%20M.%20I.%2C%20%26amp%3B%20Claeys%2C%20P.%20%282023%29.%20Comprehensive%20refutation%20of%20the%20Younger%20Dryas%20Impact%20Hypothesis%20%28YDIH%29.%20%3Ci%3EEarth-Science%20Reviews%3C%5C%2Fi%3E%2C%20%3Ci%3E247%3C%5C%2Fi%3E%2C%20104502.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1016%5C%2Fj.earscirev.2023.104502%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1016%5C%2Fj.earscirev.2023.104502%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Comprehensive%20refutation%20of%20the%20Younger%20Dryas%20Impact%20Hypothesis%20%28YDIH%29%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Vance%20T.%22%2C%22lastName%22%3A%22Holliday%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Tyrone%20L.%22%2C%22lastName%22%3A%22Daulton%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Patrick%20J.%22%2C%22lastName%22%3A%22Bartlein%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Mark%20B.%22%2C%22lastName%22%3A%22Boslough%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ryan%20P.%22%2C%22lastName%22%3A%22Breslawski%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Abigail%20E.%22%2C%22lastName%22%3A%22Fisher%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ian%20A.%22%2C%22lastName%22%3A%22Jorgeson%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Andrew%20C.%22%2C%22lastName%22%3A%22Scott%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Christian%22%2C%22lastName%22%3A%22Koeberl%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jennifer%20R.%22%2C%22lastName%22%3A%22Marlon%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jeffrey%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Michail%20I.%22%2C%22lastName%22%3A%22Petaev%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Philippe%22%2C%22lastName%22%3A%22Claeys%22%7D%5D%2C%22abstractNote%22%3A%22%22%2C%22date%22%3A%2212%5C%2F2023%22%2C%22language%22%3A%22en%22%2C%22DOI%22%3A%2210.1016%5C%2Fj.earscirev.2023.104502%22%2C%22ISSN%22%3A%2200128252%22%2C%22url%22%3A%22https%3A%5C%2F%5C%2Flinkinghub.elsevier.com%5C%2Fretrieve%5C%2Fpii%5C%2FS0012825223001915%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222023-12-18T17%3A57%3A21Z%22%7D%7D%2C%7B%22key%22%3A%22SUD3XV4K%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Thompson%20et%20al.%22%2C%22parsedDate%22%3A%222022-11-08%22%2C%22numChildren%22%3A0%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EThompson%2C%20L.%20G.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20Yao%2C%20T.%2C%20Davis%2C%20M.%20E.%2C%20Mosley-Thompson%2C%20E.%2C%20Beaudon%2C%20E.%2C%20Sierra-Hern%26%23xE1%3Bndez%2C%20M.%20R.%2C%20%26amp%3B%20Porter%2C%20S.%20E.%20%282022%29.%20Use%20of%20%26%23x3B4%3B%20%3Csup%3E18%3C%5C%2Fsup%3E%20O%20%3Csub%3Eatm%3C%5C%2Fsub%3E%20in%20dating%20a%20Tibetan%20ice%20core%20record%20of%20Holocene%5C%2FLate%20Glacial%20climate.%20%3Ci%3EProceedings%20of%20the%20National%20Academy%20of%20Sciences%3C%5C%2Fi%3E%2C%20%3Ci%3E119%3C%5C%2Fi%3E%2845%29%2C%20e2205545119.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1073%5C%2Fpnas.2205545119%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1073%5C%2Fpnas.2205545119%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Use%20of%20%5Cu03b4%20%3Csup%3E18%3C%5C%2Fsup%3E%20O%20%3Csub%3Eatm%3C%5C%2Fsub%3E%20in%20dating%20a%20Tibetan%20ice%20core%20record%20of%20Holocene%5C%2FLate%20Glacial%20climate%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Lonnie%20G.%22%2C%22lastName%22%3A%22Thompson%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jeffrey%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Tandong%22%2C%22lastName%22%3A%22Yao%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Mary%20E.%22%2C%22lastName%22%3A%22Davis%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Ellen%22%2C%22lastName%22%3A%22Mosley-Thompson%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Emilie%22%2C%22lastName%22%3A%22Beaudon%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%20Roxana%22%2C%22lastName%22%3A%22Sierra-Hern%5Cu00e1ndez%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Stacy%20E.%22%2C%22lastName%22%3A%22Porter%22%7D%5D%2C%22abstractNote%22%3A%22Ice%20cores%20from%20the%20northwestern%20Tibetan%20Plateau%20%28NWTP%29%20contain%20long%20records%20of%20regional%20climate%20variability%2C%20but%20refrozen%20meltwater%20and%20dust%20in%20these%20cores%20has%20hampered%20development%20of%20robust%20timescales.%20Here%2C%20we%20introduce%20an%20approach%20to%20dating%20the%20ice%20via%20the%20isotopic%20composition%20of%20atmospheric%20O%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%202%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20in%20air%20bubbles%20%28%5Cu03b4%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%2018%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20O%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20atm%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%29%2C%20along%20with%20annual%20layer%20counting%20and%20radiocarbon%20dating.%20We%20provide%20a%20robust%20chronology%20for%20water%20isotope%20records%20%28%5Cu03b4%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%2018%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20O%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20ice%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20and%20d-excess%29%20from%20three%20ice%20cores%20from%20the%20Guliya%20ice%20cap%20in%20the%20NWTP.%20The%20measurement%20of%20%5Cu03b4%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%2018%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20O%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20atm%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%2C%20although%20common%20in%20polar%20ice%20core%20timescales%2C%20has%20rarely%20been%20used%20on%20ice%20cores%20from%20low-latitude%2C%20high-altitude%20glaciers%20due%20to%20%281%29%20low%20air%20pressure%2C%20%282%29%20the%20common%20presence%20of%20refrozen%20melt%20that%20adds%20dissolved%20gases%20and%20reduces%20the%20amount%20of%20air%20available%20for%20analysis%2C%20and%20%283%29%20the%20respiratory%20consumption%20of%20molecular%20oxygen%20%28O%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%202%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%29%20by%20micro-organisms%20in%20the%20ice%2C%20which%20fractionates%20the%20%5Cu03b4%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%2018%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20O%20of%20O%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%202%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20from%20the%20atmospheric%20value.%20Here%2C%20we%20make%20corrections%20for%20melt%20and%20respiration%20to%20address%20these%20complications.%20The%20resulting%20records%20of%20water%20isotopes%20from%20the%20Guliya%20ice%20cores%20reveal%20climatic%20variations%20over%20the%20last%2015%2C000%20y%2C%20the%20timings%20of%20which%20correspond%20to%20those%20observed%20in%20independently%20dated%20lake%20and%20speleothem%20records%20and%20confirm%20that%20the%20Guliya%20ice%20cap%20existed%20before%20the%20Holocene.%20The%20millennial-scale%20drivers%20of%20%5Cu03b4%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%2018%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20O%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20ice%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20are%20complex%20and%20temporally%20variable%3B%20however%2C%20Guliya%20%5Cu03b4%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%2018%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20O%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20ice%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20values%20since%20the%20mid-20th%20century%20are%20the%20highest%20since%20the%20beginning%20of%20the%20Holocene%20and%20have%20increased%20with%20regional%20air%20temperature.%22%2C%22date%22%3A%222022-11-08%22%2C%22language%22%3A%22en%22%2C%22DOI%22%3A%2210.1073%5C%2Fpnas.2205545119%22%2C%22ISSN%22%3A%220027-8424%2C%201091-6490%22%2C%22url%22%3A%22https%3A%5C%2F%5C%2Fpnas.org%5C%2Fdoi%5C%2F10.1073%5C%2Fpnas.2205545119%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222023-02-17T16%3A59%3A00Z%22%7D%7D%2C%7B%22key%22%3A%22NXXLFDZZ%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Dong%20et%20al.%22%2C%22parsedDate%22%3A%222022-10%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EDong%2C%20X.%20Y.%2C%20Kathayat%2C%20G.%2C%20Rasmussen%2C%20S.%20O.%2C%20Svensson%2C%20A.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20Li%2C%20H.%20Y.%2C%20Sinha%2C%20A.%2C%20Xu%2C%20Y.%2C%20Zhang%2C%20H.%20W.%2C%20Shi%2C%20Z.%20G.%2C%20Cai%2C%20Y.%20J.%2C%20Perez-Mejias%2C%20C.%2C%20Baker%2C%20J.%2C%20Zhao%2C%20J.%20Y.%2C%20Spotl%2C%20C.%2C%20Columbu%2C%20A.%2C%20Ning%2C%20Y.%20F.%2C%20Strikis%2C%20N.%20M.%2C%20Chen%2C%20S.%20T.%2C%20%26%23x2026%3B%20Cheng%2C%20H.%20%282022%29.%20Coupled%20atmosphere-ice-ocean%20dynamics%20during%20Heinrich%20Stadial%202.%20%3Ci%3ENature%20Communications%3C%5C%2Fi%3E%2C%20%3Ci%3E13%3C%5C%2Fi%3E%281%29%2C%2014.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1038%5C%2Fs41467-022-33583-4%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1038%5C%2Fs41467-022-33583-4%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Coupled%20atmosphere-ice-ocean%20dynamics%20during%20Heinrich%20Stadial%202%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22X.%20Y.%22%2C%22lastName%22%3A%22Dong%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22G.%22%2C%22lastName%22%3A%22Kathayat%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%20O.%22%2C%22lastName%22%3A%22Rasmussen%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%22%2C%22lastName%22%3A%22Svensson%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22H.%20Y.%22%2C%22lastName%22%3A%22Li%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%22%2C%22lastName%22%3A%22Sinha%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Y.%22%2C%22lastName%22%3A%22Xu%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22H.%20W.%22%2C%22lastName%22%3A%22Zhang%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Z.%20G.%22%2C%22lastName%22%3A%22Shi%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Y.%20J.%22%2C%22lastName%22%3A%22Cai%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%22%2C%22lastName%22%3A%22Perez-Mejias%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Baker%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20Y.%22%2C%22lastName%22%3A%22Zhao%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%22%2C%22lastName%22%3A%22Spotl%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%22%2C%22lastName%22%3A%22Columbu%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Y.%20F.%22%2C%22lastName%22%3A%22Ning%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22N.%20M.%22%2C%22lastName%22%3A%22Strikis%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%20T.%22%2C%22lastName%22%3A%22Chen%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22X.%20F.%22%2C%22lastName%22%3A%22Wang%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%20K.%22%2C%22lastName%22%3A%22Gupta%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%22%2C%22lastName%22%3A%22Dutt%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22F.%22%2C%22lastName%22%3A%22Zhang%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22F.%20W.%22%2C%22lastName%22%3A%22Cruz%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Z.%20S.%22%2C%22lastName%22%3A%22An%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%20L.%22%2C%22lastName%22%3A%22Edwards%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22H.%22%2C%22lastName%22%3A%22Cheng%22%7D%5D%2C%22abstractNote%22%3A%22Our%20understanding%20of%20climate%20dynamics%20during%20millennial-scale%20events%20is%20incomplete%2C%20partially%20due%20to%20the%20lack%20of%20their%20precise%20phase%20analyses%20under%20various%20boundary%20conditions.%20Here%20we%20present%20nine%20speleothem%20oxygen-isotope%20records%20from%20mid-to-low-latitude%20monsoon%20regimes%20with%20subcentennial%20age%20precision%20and%20multi-annual%20resolution%2C%20spanning%20the%20Heinrich%20Stadial%202%20%28HS2%29%20-%20a%20millennial-scale%20event%20that%20occurred%20at%20the%20Last%20Glacial%20Maximum.%20Our%20data%20suggests%20that%20the%20Greenland%20and%20Antarctic%20ice-core%20chronologies%20require%20%2B320-%20and%20%2B400-year%20adjustments%2C%20respectively%2C%20supported%20by%20extant%20volcanic%20evidence%20and%20radiocarbon%20ages.%20Our%20chronological%20framework%20shows%20a%20synchronous%20HS2%20onset%20globally.%20Our%20records%20precisely%20characterize%20a%20centennial-scale%20abrupt%20%5C%22tropical%20atmospheric%20seesaw%5C%22%20superimposed%20on%20the%20conventional%20%5C%22bipolar%20seesaw%5C%22%20at%20the%20beginning%20of%20HS2%2C%20implying%20a%20unique%20response%5C%2Ffeedback%20from%20low-latitude%20hydroclimate.%20Together%20with%20our%20observation%20of%20an%20early%20South%20American%20monsoon%20shift%20at%20the%20HS2%20termination%2C%20we%20suggest%20a%20more%20active%20role%20of%20low-latitude%20hydroclimate%20dynamics%20underlying%20millennial%20events%20than%20previously%20thought.%22%2C%22date%22%3A%22Oct%202022%22%2C%22language%22%3A%22English%22%2C%22DOI%22%3A%2210.1038%5C%2Fs41467-022-33583-4%22%2C%22ISSN%22%3A%22%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-10-26T23%3A06%3A16Z%22%7D%7D%2C%7B%22key%22%3A%22M4TYAZEC%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Menking%20et%20al.%22%2C%22parsedDate%22%3A%222022-09-16%22%2C%22numChildren%22%3A0%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EMenking%2C%20J.%20A.%2C%20Shackleton%2C%20S.%20A.%2C%20Bauska%2C%20T.%20K.%2C%20Buffen%2C%20A.%20M.%2C%20Brook%2C%20E.%20J.%2C%20Barker%2C%20S.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20Dyonisius%2C%20M.%20N.%2C%20%26amp%3B%20Petrenko%2C%20V.%20V.%20%282022%29.%20Multiple%20carbon%20cycle%20mechanisms%20associated%20with%20the%20glaciation%20of%20Marine%20Isotope%20Stage%204.%20%3Ci%3ENature%20Communications%3C%5C%2Fi%3E%2C%20%3Ci%3E13%3C%5C%2Fi%3E%281%29%2C%205443.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1038%5C%2Fs41467-022-33166-3%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1038%5C%2Fs41467-022-33166-3%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Multiple%20carbon%20cycle%20mechanisms%20associated%20with%20the%20glaciation%20of%20Marine%20Isotope%20Stage%204%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22James%20A.%22%2C%22lastName%22%3A%22Menking%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Sarah%20A.%22%2C%22lastName%22%3A%22Shackleton%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Thomas%20K.%22%2C%22lastName%22%3A%22Bauska%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Aron%20M.%22%2C%22lastName%22%3A%22Buffen%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Edward%20J.%22%2C%22lastName%22%3A%22Brook%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Stephen%22%2C%22lastName%22%3A%22Barker%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jeffrey%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Michael%20N.%22%2C%22lastName%22%3A%22Dyonisius%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Vasilii%20V.%22%2C%22lastName%22%3A%22Petrenko%22%7D%5D%2C%22abstractNote%22%3A%22Abstract%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20Here%20we%20use%20high-precision%20carbon%20isotope%20data%20%28%5Cu03b4%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%2013%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20C-CO%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%202%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20%29%20to%20show%20atmospheric%20CO%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%202%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20during%20Marine%20Isotope%20Stage%204%20%28MIS%204%2C%20~70.5-59%20ka%29%20was%20controlled%20by%20a%20succession%20of%20millennial-scale%20processes.%20Enriched%20%5Cu03b4%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%2013%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20C-CO%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%202%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20during%20peak%20glaciation%20suggests%20increased%20ocean%20carbon%20storage.%20Variations%20in%20%5Cu03b4%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%2013%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20C-CO%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%202%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20in%20early%20MIS%204%20suggest%20multiple%20processes%20were%20active%20during%20CO%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%202%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20drawdown%2C%20potentially%20including%20decreased%20land%20carbon%20and%20decreased%20Southern%20Ocean%20air-sea%20gas%20exchange%20superposed%20on%20increased%20ocean%20carbon%20storage.%20CO%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%202%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20remained%20low%20during%20MIS%204%20while%20%5Cu03b4%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%2013%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20C-CO%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%202%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20fluctuations%20suggest%20changes%20in%20Southern%20Ocean%20and%20North%20Atlantic%20air-sea%20gas%20exchange.%20A%207%20ppm%20increase%20in%20CO%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%202%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20at%20the%20onset%20of%20Dansgaard-Oeschger%20event%2019%20%2872.1%20ka%29%20and%2027%20ppm%20increase%20in%20CO%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%202%5Cn%20%20%20%20%20%20%20%20%20%20%20%20%20%20during%20late%20MIS%204%20%28Heinrich%20Stadial%206%2C%20~63.5-60%20ka%29%20involved%20additions%20of%20isotopically%20light%20carbon%20to%20the%20atmosphere.%20The%20terrestrial%20biosphere%20and%20Southern%20Ocean%20air-sea%20gas%20exchange%20are%20possible%20sources%2C%20with%20the%20latter%20event%20also%20involving%20decreased%20ocean%20carbon%20storage.%22%2C%22date%22%3A%222022-09-16%22%2C%22language%22%3A%22en%22%2C%22DOI%22%3A%2210.1038%5C%2Fs41467-022-33166-3%22%2C%22ISSN%22%3A%222041-1723%22%2C%22url%22%3A%22https%3A%5C%2F%5C%2Fwww.nature.com%5C%2Farticles%5C%2Fs41467-022-33166-3%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-10-11T18%3A10%3A06Z%22%7D%7D%2C%7B%22key%22%3A%2236VFQV3D%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Morgan%20et%20al.%22%2C%22parsedDate%22%3A%222022-07-22%22%2C%22numChildren%22%3A0%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EMorgan%2C%20J.%20D.%2C%20Buizert%2C%20C.%2C%20Fudge%2C%20T.%20J.%2C%20Kawamura%2C%20K.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20%26amp%3B%20Trudinger%2C%20C.%20M.%20%282022%29.%20Gas%20isotope%20thermometry%20in%20the%20South%20Pole%20and%20Dome%20Fuji%20ice%20cores%20provides%20evidence%20for%20seasonal%20rectification%20of%20ice%20core%20gas%20records.%20%3Ci%3EThe%20Cryosphere%3C%5C%2Fi%3E%2C%20%3Ci%3E16%3C%5C%2Fi%3E%287%29%2C%202947%26%23x2013%3B2966.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Ftc-16-2947-2022%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Ftc-16-2947-2022%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Gas%20isotope%20thermometry%20in%20the%20South%20Pole%20and%20Dome%20Fuji%20ice%20cores%20provides%20evidence%20for%20seasonal%20rectification%20of%20ice%20core%20gas%20records%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jacob%20D.%22%2C%22lastName%22%3A%22Morgan%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Christo%22%2C%22lastName%22%3A%22Buizert%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Tyler%20J.%22%2C%22lastName%22%3A%22Fudge%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Kenji%22%2C%22lastName%22%3A%22Kawamura%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Jeffrey%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Cathy%20M.%22%2C%22lastName%22%3A%22Trudinger%22%7D%5D%2C%22abstractNote%22%3A%22Abstract.%20Gas%20isotope%20thermometry%20using%20the%20isotopes%20of%20molecular%20nitrogen%20and%20argon%5Cnhas%20been%20used%20extensively%20to%20reconstruct%20past%20surface%20temperature%20change%5Cnfrom%20Greenland%20ice%20cores.%20The%20gas%20isotope%20ratios%20%5Cu03b415N%20and%5Cn%5Cu03b440Ar%20in%20the%20ice%20core%20are%20each%20set%20by%20the%20amount%20of%5Cngravitational%20and%20thermal%20fractionation%20in%20the%20firn.%20The%20gravitational%5Cncomponent%20of%20fractionation%20is%20proportional%20to%20the%20firn%20thickness%2C%20and%20the%5Cnthermal%20component%20is%20proportional%20to%20the%20temperature%20difference%20between%20the%5Cntop%20and%20bottom%20of%20the%20firn%20column%2C%20which%20can%20be%20related%20to%20surface%5Cntemperature%20change.%20Compared%20to%20Greenland%2C%20Antarctic%20climate%20change%20is%5Cntypically%20more%20gradual%20and%20smaller%20in%20magnitude%2C%20which%20results%20in%20smaller%5Cnthermal%20fractionation%20signals%20that%20are%20harder%20to%20detect.%20This%20has%20hampered%5Cnapplication%20of%20gas%20isotope%20thermometry%20to%20Antarctic%20ice%20cores.%20Here%2C%20we%20present%20an%20analytical%20method%20for%20measuring%20%5Cu03b415N%20and%5Cn%5Cu03b440Ar%20with%20a%20precision%20of%200.002%5Cu2009%5Cu2030%20per%20atomic%5Cnmass%20unit%2C%20a%20two-fold%20improvement%20on%20previous%20work.%20This%20allows%20us%20to%5Cnreconstruct%20changes%20in%20firn%20thickness%20and%20temperature%20difference%20at%20the%20South%5CnPole%20between%2030%20and%205%5Cu2009kyr%5Cu2009BP.%20We%20find%20that%20variability%20in%20firn%20thickness%20is%5Cncontrolled%20in%20part%20by%20changes%20in%20snow%20accumulation%20rate%2C%20which%20is%2C%20in%20turn%2C%5Cninfluenced%20strongly%20by%20the%20along-flowline%20topography%20upstream%20of%20the%20ice%5Cncore%20site.%20Variability%20in%20our%20firn%20temperature%20difference%20record%20cannot%20be%5Cnexplained%20by%20annual-mean%20processes.%20We%20therefore%20propose%20that%20the%20ice%20core%5Cngas%20isotopes%20contain%20a%20seasonal%20bias%20due%20to%20rectification%20of%20seasonal%5Cnsignals%20in%20the%20upper%20firn.%20The%20strength%20of%20the%20rectification%20also%20appears%20to%5Cnbe%20linked%20to%20fluctuations%20in%20the%20upstream%20topography.%20As%20further%20evidence%5Cnfor%20the%20existence%20of%20rectification%2C%20we%20present%20new%20data%20from%20the%20Dome%20Fuji%5Cnice%20core%20that%20are%20also%20consistent%20with%20a%20seasonal%20bias%20throughout%20the%5CnHolocene.%20Our%20findings%20have%20important%20implications%20for%20the%20interpretation%20of%20ice%20core%5Cngas%20records.%20For%20example%2C%20we%20show%20that%20the%20effects%20of%20upstream%20topography%20on%5Cnice%20core%20records%20can%20be%20significant%20at%20flank%20sites%20like%20the%20South%20Pole%20%5Cu2013%20they%5Cnare%20responsible%20for%20some%20of%20the%20largest%20signals%20in%20our%20record.%20Presumably%5Cnupstream%20signals%20impact%20other%20flank-flow%20ice%20cores%20such%20as%20EDML%2C%20Vostok%2C%20and%5CnEGRIP%20similarly.%20Additionally%2C%20future%20work%20is%20required%20to%20confirm%20the%5Cnexistence%20of%20seasonal%20rectification%20in%20polar%20firn%2C%20to%20determine%20how%20spatially%5Cnand%20temporally%20widespread%20rectifier%20effects%20are%2C%20and%20to%20incorporate%20the%5Cnrelevant%20physics%20into%20firn%20air%20models.%22%2C%22date%22%3A%222022-07-22%22%2C%22language%22%3A%22en%22%2C%22DOI%22%3A%2210.5194%5C%2Ftc-16-2947-2022%22%2C%22ISSN%22%3A%221994-0424%22%2C%22url%22%3A%22https%3A%5C%2F%5C%2Ftc.copernicus.org%5C%2Farticles%5C%2F16%5C%2F2947%5C%2F2022%5C%2F%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-08-15T20%3A23%3A34Z%22%7D%7D%2C%7B%22key%22%3A%22JBV3PVUJ%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Birner%20et%20al.%22%2C%22parsedDate%22%3A%222022-05%22%2C%22numChildren%22%3A4%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EBirner%2C%20B.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%2C%20Paplawsky%2C%20B.%2C%20%26amp%3B%20Keeling%2C%20R.%20F.%20%282022%29.%20Increasing%20atmospheric%20helium%20due%20to%20fossil%20fuel%20exploitation.%20%3Ci%3ENature%20Geoscience%3C%5C%2Fi%3E%2C%20%3Ci%3E15%3C%5C%2Fi%3E%285%29%2C%20346-%2B.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1038%5C%2Fs41561-022-00932-3%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1038%5C%2Fs41561-022-00932-3%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Increasing%20atmospheric%20helium%20due%20to%20fossil%20fuel%20exploitation%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22B.%22%2C%22lastName%22%3A%22Birner%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22B.%22%2C%22lastName%22%3A%22Paplawsky%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%20F.%22%2C%22lastName%22%3A%22Keeling%22%7D%5D%2C%22abstractNote%22%3A%22Fossil%20fuels%20contain%20small%20amounts%20of%20helium%2C%20which%20are%20co-released%20into%20the%20atmosphere%20together%20with%20carbon%20dioxide.%20However%2C%20a%20clear%20build-up%20of%20helium%20in%20the%20atmosphere%20has%20not%20previously%20been%20detected.%20Using%20a%20high-precision%20mass%20spectrometry%20technique%20to%20determine%20the%20atmospheric%20ratio%20of%20helium-4%20to%20nitrogen%2C%20we%20show%20that%20helium-4%20concentrations%20have%20increased%20significantly%20over%20the%20past%20five%20decades.%20Obtaining%20a%20direct%20measure%20of%20the%20rise%20in%20atmospheric%20helium-4%20is%20possible%20because%20changes%20in%20nitrogen%20are%20negligible.%20Using%2046%20air%20samples%20acquired%20between%201974%20and%202020%2C%20we%20find%20that%20the%20helium-4%20concentration%20increased%20at%20an%20average%20rate%20of%2039%20%2B%5C%2F-%203%20billion%20mol%20per%20year%20%282%20sigma%29.%20Given%20that%20previous%20observations%20have%20shown%20that%20the%20ratio%20between%20helium-3%20and%20helium-4%20in%20the%20atmosphere%20has%20remained%20constant%2C%20our%20results%20also%20imply%20that%20the%20concentration%20of%20helium-3%20is%20increasing.%20The%20inferred%20rise%20in%20atmospheric%20helium-3%20greatly%20exceeds%20estimates%20of%20anthropogenic%20emissions%20from%20natural%20gas%2C%20nuclear%20weapons%20and%20nuclear%20power%20generation%2C%20suggesting%20potential%20problems%20with%20previous%20isotope%20measurements%20or%20an%20incorrect%20assessment%20of%20known%20sources.%20Mass%20spectrometry%20measurements%20show%20that%20the%20concentration%20of%20helium%20in%20the%20atmosphere%20has%20risen%20over%20the%20past%20five%20decades%20due%20to%20fossil%20fuel%20emissions.%22%2C%22date%22%3A%222022%5C%2F05%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.1038%5C%2Fs41561-022-00932-3%22%2C%22ISSN%22%3A%221752-0894%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22EU5YC9TT%22%2C%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-07-12T21%3A01%3A34Z%22%7D%7D%2C%7B%22key%22%3A%226HVN3JZD%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Yan%20et%20al.%22%2C%22parsedDate%22%3A%222021-12%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EYan%2C%20Y.%20Z.%2C%20Brook%2C%20E.%20J.%2C%20Kurbatov%2C%20A.%20V.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20%26amp%3B%20Higgins%2C%20J.%20A.%20%282021%29.%20Ice%20core%20evidence%20for%20atmospheric%20oxygen%20decline%20since%20the%20Mid-Pleistocene%20transition.%20%3Ci%3EScience%20Advances%3C%5C%2Fi%3E%2C%20%3Ci%3E7%3C%5C%2Fi%3E%2851%29%2C%2011.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1126%5C%2Fsciadv.abj9341%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1126%5C%2Fsciadv.abj9341%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Ice%20core%20evidence%20for%20atmospheric%20oxygen%20decline%20since%20the%20Mid-Pleistocene%20transition%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Y.%20Z.%22%2C%22lastName%22%3A%22Yan%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20J.%22%2C%22lastName%22%3A%22Brook%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%20V.%22%2C%22lastName%22%3A%22Kurbatov%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20A.%22%2C%22lastName%22%3A%22Higgins%22%7D%5D%2C%22abstractNote%22%3A%22The%20history%20of%20atmospheric%20oxygen%20%28PO2%29%20and%20the%20processes%20that%20act%20to%20regulate%20it%20remain%20enigmatic%20because%20of%20difficulties%20in%20quantitative%20reconstructions%20using%20indirect%20proxies.%20Here%2C%20we%20extend%20the%20ice-core%20record%20of%20PO2%20using%201.5-million-year-old%20%28Ma%29%20discontinuous%20ice%20samples%20drilled%20from%20Allan%20Hills%20Blue%20Ice%20Area%2C%20East%20Antarctica.%20No%20statistically%20significant%20difference%20exists%20in%20PO2%20between%20samples%20at%201.5%20Ma%20and%20810%20thousand%20years%20%28ka%29%2C%20suggesting%20that%20the%20Late-Pleistocene%20imbalance%20in%20O-2%20sources%20and%20sinks%20began%20around%20the%20time%20of%20the%20transition%20from%2040-%20to%20100-ka%20glacial%20cycles%20in%20the%20Mid-Pleistocene%20between%20-1.2%20Ma%20and%20700%20ka.%20The%20absence%20of%20a%20coeval%20secular%20increase%20in%20atmospheric%20CO2%20over%20the%20past%20similar%20to%201%20Ma%20requires%20negative%20feedback%20mechanisms%20such%20as%20Pco%282%29-dependent%20silicate%20weathering.%20Fast%20processes%20must%20also%20act%20to%20suppress%20the%20immediate%20Pco%282%29%20increase%20because%20of%20the%20imbalance%20in%20O-2%20sinks%20over%20sources%20beginning%20in%20the%20Mid-Pleistocene.%22%2C%22date%22%3A%222021%5C%2F12%22%2C%22language%22%3A%22English%22%2C%22DOI%22%3A%2210.1126%5C%2Fsciadv.abj9341%22%2C%22ISSN%22%3A%222375-2548%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A18Z%22%7D%7D%2C%7B%22key%22%3A%22J4EDNLCJ%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Oyabu%20et%20al.%22%2C%22parsedDate%22%3A%222021-12%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EOyabu%2C%20I.%2C%20Kawamura%2C%20K.%2C%20Uchida%2C%20T.%2C%20Fujita%2C%20S.%2C%20Kitamura%2C%20K.%2C%20Hirabayashi%2C%20M.%2C%20Aoki%2C%20S.%2C%20Morimoto%2C%20S.%2C%20Nakazawa%2C%20T.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20%26amp%3B%20Morgan%2C%20J.%20D.%20%282021%29.%20Fractionation%20of%20O-2%5C%2FN-2%20and%20Ar%5C%2FN-2%20in%20the%20Antarctic%20ice%20sheet%20during%20bubble%20formation%20and%20bubble-clathrate%20hydrate%20transition%20from%20precise%20gas%20measurements%20of%20the%20Dome%20Fuji%20ice%20core.%20%3Ci%3ECryosphere%3C%5C%2Fi%3E%2C%20%3Ci%3E15%3C%5C%2Fi%3E%2812%29%2C%205529%26%23x2013%3B5555.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Ftc-15-5529-2021%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Ftc-15-5529-2021%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Fractionation%20of%20O-2%5C%2FN-2%20and%20Ar%5C%2FN-2%20in%20the%20Antarctic%20ice%20sheet%20during%20bubble%20formation%20and%20bubble-clathrate%20hydrate%20transition%20from%20precise%20gas%20measurements%20of%20the%20Dome%20Fuji%20ice%20core%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22I.%22%2C%22lastName%22%3A%22Oyabu%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22K.%22%2C%22lastName%22%3A%22Kawamura%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%22%2C%22lastName%22%3A%22Uchida%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%22%2C%22lastName%22%3A%22Fujita%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22K.%22%2C%22lastName%22%3A%22Kitamura%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Hirabayashi%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%22%2C%22lastName%22%3A%22Aoki%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%22%2C%22lastName%22%3A%22Morimoto%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%22%2C%22lastName%22%3A%22Nakazawa%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20D.%22%2C%22lastName%22%3A%22Morgan%22%7D%5D%2C%22abstractNote%22%3A%22The%20variations%20of%20delta%20O-2%5C%2FN-2%20and%20delta%20Ar%5C%2FN-2%20in%20the%20Dome%20Fuji%20ice%20core%20were%20measured%20from%20112%20m%20%28bubbly%20ice%29%20to%202001%20m%20%28clathrate%20hydrate%20ice%29.%20Our%20method%2C%20combined%20with%20the%20low%20storage%20temperature%20of%20the%20samples%20%28-50%20degrees%20C%29%2C%20successfully%20excludes%20post-coring%20gas-loss%20fractionation%20signals%20from%20our%20data.%20From%20the%20bubbly%20ice%20to%20the%20middle%20of%20the%20bubble-clathrate%20transition%20zone%20%28BCTZ%29%20%28112-800m%29%20and%20below%20the%20BCTZ%20%28%3E%201200%20m%29%2C%20the%20delta%20O-2%5C%2FN-2%20and%20delta%20Ar%5C%2FN-2%20data%20exhibit%20orbital-scale%20variations%20similar%20to%20local%20summer%20insolation.%20The%20data%20in%20the%20lower%20BCTZ%20%28800-1200%20m%29%20have%20large%20scatter%2C%20which%20may%20be%20caused%20by%20millimeter-scale%20inhomogeneity%20of%20air%20composition%20combined%20with%20finite%20sample%20lengths.%20The%20insolation%20signal%20originally%20recorded%20at%20the%20bubble%20close-off%20remains%20through%20the%20BCTZ%2C%20and%20the%20insolation%20signal%20may%20be%20reconstructed%20by%20analyzing%20long%20ice%20samples%20%28more%20than%2050%20cm%20for%20the%20Dome%20Fuji%20core%29.%20In%20the%20clathrate%20hydrate%20zone%2C%20the%20scatter%20around%20the%20orbital-scale%20variability%20decreases%20with%20depth%2C%20indicating%20diffusive%20smoothing%20of%20delta%20O-2%5C%2FN-2%20and%20delta%20Ar%5C%2FN-2.%20A%20simple%20gas%20diffusion%20model%20was%20used%20to%20reproduce%20the%20smoothing%20and%20thus%20constrain%20their%20permeation%20coefficients.%20The%20relationship%20between%20delta%20Ar%5C%2FN-2%20and%20delta%20O-2%5C%2FN-2%20is%20markedly%20different%20for%20the%20datasets%20representing%20bubble%20close-off%20%28slope%20similar%20to%200.5%29%2C%20bubble-clathrate%20hydrate%20transformation%20%28similar%20to%201%29%2C%20and%20post-coring%20gas%20loss%20%28similar%20to%200.2%29%2C%20suggesting%20that%20the%20contributions%20of%20the%20mass-independent%20and%20mass-dependent%20fractionation%20processes%20are%20different%20for%20those%20cases.%20The%20method%20and%20data%20presented%20here%20may%20be%20useful%20for%20improving%20the%20orbital%20dating%20of%20deep%20ice%20cores%20over%20the%20multiple%20glacial%20cycles%20and%20further%20studying%20non-insolation-driven%20signals%20%28e.g.%2C%20atmospheric%20composition%29%20of%20these%20gases.%22%2C%22date%22%3A%222021%5C%2F12%22%2C%22language%22%3A%22English%22%2C%22DOI%22%3A%2210.5194%5C%2Ftc-15-5529-2021%22%2C%22ISSN%22%3A%221994-0416%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A17Z%22%7D%7D%2C%7B%22key%22%3A%22JR9N29ZY%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Seltzer%20et%20al.%22%2C%22parsedDate%22%3A%222021-11%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3ESeltzer%2C%20A.%20M.%2C%20Krantz%2C%20J.%20A.%2C%20Ng%2C%20J.%2C%20Danskin%2C%20W.%20R.%2C%20Bekaert%2C%20D.%20V.%2C%20Barry%2C%20P.%20H.%2C%20Kimbrough%2C%20D.%20L.%2C%20Kulongoski%2C%20J.%20T.%2C%20%26amp%3B%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%20%282021%29.%20The%20triple%20argon%20isotope%20composition%20of%20groundwater%20on%20ten-thousand-year%20timescales.%20%3Ci%3EChemical%20Geology%3C%5C%2Fi%3E%2C%20%3Ci%3E583%3C%5C%2Fi%3E%2C%2010.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1016%5C%2Fj.chemgeo.2021.120458%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1016%5C%2Fj.chemgeo.2021.120458%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22The%20triple%20argon%20isotope%20composition%20of%20groundwater%20on%20ten-thousand-year%20timescales%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%20M.%22%2C%22lastName%22%3A%22Seltzer%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20A.%22%2C%22lastName%22%3A%22Krantz%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Ng%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22W.%20R.%22%2C%22lastName%22%3A%22Danskin%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22D.%20V.%22%2C%22lastName%22%3A%22Bekaert%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22P.%20H.%22%2C%22lastName%22%3A%22Barry%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22D.%20L.%22%2C%22lastName%22%3A%22Kimbrough%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20T.%22%2C%22lastName%22%3A%22Kulongoski%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%5D%2C%22abstractNote%22%3A%22Understanding%20the%20age%20and%20movement%20of%20groundwater%20is%20important%20for%20predicting%20the%20vulnerability%20of%20wells%20to%20contamination%2C%20constraining%20flow%20models%20that%20inform%20sustainable%20groundwater%20management%2C%20and%20interpreting%20geochemical%20signals%20that%20reflect%20past%20climate.%20Due%20to%20both%20the%20ubiquity%20of%20groundwater%20with%20order%20ten-thousand-year%20residence%20times%20and%20its%20importance%20for%20climate%20reconstruction%20of%20the%20last%20glacial%20period%2C%20there%20is%20a%20strong%20need%20for%20improving%20geochemical%20dating%20tools%20on%20this%20timescale.%20Whereas%20C-14%20of%20dissolved%20inorganic%20carbon%20and%20dissolved%20He-4%20are%20common%20age%20tracers%20for%20Late%20Pleistocene%20groundwater%2C%20each%20is%20limited%20by%20systematic%20uncertainties%20related%20to%20aquifer%20composition%20and%20lithology%2C%20and%20the%20extent%20of%20water-rock%20interaction.%20In%20principle%2C%20radiogenic%20Ar-40%20in%20groundwater%20acquired%20from%20decay%20of%2040K%20in%20aquifer%20minerals%20should%20be%20insensitive%20to%20some%20processes%20that%20impact%20C-14%20and%20He-4%20and%20thus%20represent%20a%20useful%2C%20complementary%20age%20tracer.%20In%20practice%2C%20however%2C%20detection%20of%20significant%20radiogenic%20Ar-40%20signals%20in%20groundwater%20has%20been%20limited%20to%20a%20small%20number%20of%20studies%20of%20extremely%20old%20groundwater%20%28%3E100%20ka%29.%20Here%20we%20present%20the%20first%20high-precision%20%28%3C1%20parts%20per%20thousand%29%20measurements%20of%20triple%20Ar%20isotopes%20%28Ar-40%2C%20Ar-38%2C%20Ar-36%29%20in%20groundwater.%20We%20introduce%20a%20model%20that%20distinguishes%20radiogenic%20Ar-40%20from%20atmospheric%20Ar-40%20by%20using%20the%20non-radiogenic%20Ar%20isotopes%20%28Ar-36%2C%20Ar-38%29%20to%20correct%20for%20mass-dependent%20fractionation.%20Using%20this%20model%2C%20we%20investigate%20variability%20in%20radiogenic%20Ar-40%20excess%20%28Delta%20Ar-40%29%20across%2058%20groundwater%20samples%20collected%20from%2036%20wells%20throughout%20California%20%28USA%29.%20We%20find%20that%20Delta%20Ar-40%20ranges%20from%20similar%20to%200%20parts%20per%20thousand%20%28the%20expected%20minimum%20value%29%20to%20%2B4.2%20parts%20per%20thousand%20across%20three%20study%20areas%20near%20Fresno%2C%20San%20Diego%2C%20and%20the%20western%20Mojave%20Desert.%20Based%20on%20measurements%20from%20a%20network%20of%2023%20scientific%20monitoring%20wells%20in%20San%20Diego%2C%20we%20find%20evidence%20for%20a%20strong%20dependence%20of%20Delta%20Ar-40%20on%20aquifer%20lithology.%20We%20suggest%20that%20Delta%20Ar-40%20is%20fundamentally%20controlled%20by%20the%20weathering%20of%20old%20K-bearing%20minerals%20and%20thus%20reflects%20both%20the%20degree%20of%20groundwater-rock%20interaction%2C%20which%20is%20related%20to%20groundwater%20age%2C%20and%20the%20integrated%20flow%20through%20different%20geological%20formations.%20Future%20studies%20of%20Late%20Pleistocene%20groundwater%20may%20benefit%20from%20high-precision%20triple%20Ar%20isotope%20measurements%20as%20a%20new%20tool%20to%20better%20interpret%20C-14-%20and%20He-4-based%20constraints%20on%20groundwater%20age%20and%20flow.%22%2C%22date%22%3A%222021%5C%2F11%22%2C%22language%22%3A%22English%22%2C%22DOI%22%3A%2210.1016%5C%2Fj.chemgeo.2021.120458%22%2C%22ISSN%22%3A%220009-2541%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A22Z%22%7D%7D%2C%7B%22key%22%3A%22AZAG4AEQ%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Shackleton%20et%20al.%22%2C%22parsedDate%22%3A%222021-10%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EShackleton%2C%20S.%2C%20Menking%2C%20J.%20A.%2C%20Brook%2C%20E.%2C%20Buizert%2C%20C.%2C%20Dyonisius%2C%20M.%20N.%2C%20Petrenko%2C%20V.%20V.%2C%20Baggenstos%2C%20D.%2C%20%26amp%3B%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%20%282021%29.%20Evolution%20of%20mean%20ocean%20temperature%20in%20Marine%20Isotope%20Stage%204.%20%3Ci%3EClimate%20of%20the%20Past%3C%5C%2Fi%3E%2C%20%3Ci%3E17%3C%5C%2Fi%3E%285%29%2C%202273%26%23x2013%3B2289.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Fcp-17-2273-2021%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Fcp-17-2273-2021%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Evolution%20of%20mean%20ocean%20temperature%20in%20Marine%20Isotope%20Stage%204%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%22%2C%22lastName%22%3A%22Shackleton%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20A.%22%2C%22lastName%22%3A%22Menking%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%22%2C%22lastName%22%3A%22Brook%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%22%2C%22lastName%22%3A%22Buizert%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%20N.%22%2C%22lastName%22%3A%22Dyonisius%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22V.%20V.%22%2C%22lastName%22%3A%22Petrenko%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22D.%22%2C%22lastName%22%3A%22Baggenstos%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%5D%2C%22abstractNote%22%3A%22Deglaciations%20are%20characterized%20by%20relatively%20fast%20and%20near-synchronous%20changes%20in%20ice%20sheet%20volume%2C%20ocean%20temperature%2C%20and%20atmospheric%20greenhouse%20gas%20concentrations%2C%20but%20glacial%20inception%20occurs%20more%20gradually.%20Understanding%20the%20evolution%20of%20ice%20sheet%2C%20ocean%2C%20and%20atmosphere%20conditions%20from%20interglacial%20to%20glacial%20maximum%20provides%20insight%20into%20the%20interplay%20of%20these%20components%20of%20the%20climate%20system.%20Using%20noble%20gas%20measurements%20in%20ancient%20ice%20samples%2C%20we%20reconstruct%20mean%20ocean%20temperature%20%28MOT%29%20from%2074%20to%2059.7%20ka%2C%20covering%20the%20Marine%20Isotope%20Stage%20%28MIS%29%205a-4%20boundary%2C%20MIS%204%2C%20and%20part%20of%20the%20MIS%204-3%20transition.%20Comparing%20this%20MOT%20reconstruction%20to%20previously%20published%20MOT%20reconstructions%20from%20the%20last%20and%20penultimate%20deglaciation%2C%20we%20find%20that%20the%20majority%20of%20the%20last%20interglacial-glacial%20ocean%20cooling%20must%20have%20occurred%20within%20MIS%205.%20MOT%20reached%20equally%20cold%20conditions%20in%20MIS%204%20as%20in%20MIS%202%20%28-2.7%20%2B%5C%2F-%200.3%20degrees%20C%20relative%20to%20the%20Holocene%2C%20-0.1%20%2B%5C%2F-%200.3%20degrees%20C%20relative%20to%20MIS%202%29.%20Using%20a%20carbon%20cycle%20model%20to%20quantify%20the%20CO2%20solubility%20pump%2C%20we%20show%20that%20ocean%20cooling%20can%20explain%20most%20of%20the%20CO2%20drawdown%20%2832%20%2B%5C%2F-%204%20of%2040%20ppm%29%20across%20MIS%205.%20Comparing%20MOT%20to%20contemporaneous%20records%20of%20benthic%20delta%20O-18%2C%20we%20find%20that%20ocean%20cooling%20can%20also%20explain%20the%20majority%20of%20the%20delta%20O-18%20increase%20across%20MIS%205%20%280.7%20parts%20per%20thousand%20of%201.3%20parts%20per%20thousand%29.%20The%20timing%20of%20ocean%20warming%20and%20cooling%20in%20the%20record%20and%20the%20comparison%20to%20coeval%20Antarctic%20isotope%20data%20suggest%20an%20intimate%20link%20between%20ocean%20heat%20content%2C%20Southern%20Hemisphere%20high-latitude%20climate%2C%20and%20ocean%20circulation%20on%20orbital%20and%20millennial%20timescales.%22%2C%22date%22%3A%222021%5C%2F10%22%2C%22language%22%3A%22English%22%2C%22DOI%22%3A%2210.5194%5C%2Fcp-17-2273-2021%22%2C%22ISSN%22%3A%221814-9324%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A16Z%22%7D%7D%2C%7B%22key%22%3A%2228PKUMRW%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Patterson%20et%20al.%22%2C%22parsedDate%22%3A%222021-09%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EPatterson%2C%20J.%20D.%2C%20Aydin%2C%20M.%2C%20Crotwell%2C%20A.%20M.%2C%20Petron%2C%20G.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20Krummel%2C%20P.%20B.%2C%20Langenfelds%2C%20R.%20L.%2C%20%26amp%3B%20Saltzman%2C%20E.%20S.%20%282021%29.%20H2%20in%20Antarctic%20firn%20air%3A%20Atmospheric%20reconstructions%20and%20implications%20for%20anthropogenic%20emissions.%20%3Ci%3EProceedings%20of%20the%20National%20Academy%20of%20Sciences%20of%20the%20United%20States%20of%20America%3C%5C%2Fi%3E%2C%20%3Ci%3E118%3C%5C%2Fi%3E%2836%29%2C%208.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1073%5C%2Fpnas.2103335118%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1073%5C%2Fpnas.2103335118%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22H2%20in%20Antarctic%20firn%20air%3A%20Atmospheric%20reconstructions%20and%20implications%20for%20anthropogenic%20emissions%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20D.%22%2C%22lastName%22%3A%22Patterson%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Aydin%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%20M.%22%2C%22lastName%22%3A%22Crotwell%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22G.%22%2C%22lastName%22%3A%22Petron%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22P.%20B.%22%2C%22lastName%22%3A%22Krummel%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%20L.%22%2C%22lastName%22%3A%22Langenfelds%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20S.%22%2C%22lastName%22%3A%22Saltzman%22%7D%5D%2C%22abstractNote%22%3A%22The%20atmospheric%20history%20of%20molecular%20hydrogen%20%28H2%29%20from%201852%20to%202003%20was%20reconstructed%20from%20measurements%20of%20firn%20air%20collected%20at%20Megadunes%2C%20Antarctica.%20The%20reconstruction%20shows%20that%20H2%20levels%20in%20the%20southern%20hemisphere%20were%20roughly%20constant%20near%20330%20parts%20per%20billion%20%28ppb%3B%20nmol%20H2%20mol-1%20air%29%20during%20the%20mid%20to%20late%201800s.%20Over%20the%20twentieth%20century%2C%20H2%20levels%20rose%20by%20about%2070%25%20to%20550%20ppb.%20The%20reconstruction%20shows%20good%20agreement%20with%20the%20H2%20atmospheric%20history%20based%20on%20firn%20air%20measurements%20from%20the%20South%20Pole.%20The%20broad%20trends%20in%20atmospheric%20H2%20over%20the%20twentieth%20century%20can%20be%20explained%20by%20increased%20methane%20oxidation%20and%20anthropogenic%20emissions.%20The%20H2%20rise%20shows%20no%20evidence%20of%20deceleration%20during%20the%20last%20quarter%20of%20the%20twentieth%20century%20despite%20an%20expected%20reduction%20in%20automotive%20emissions%20following%20more%20stringent%20regulations.%20During%20the%20late%20twentieth%20century%2C%20atmospheric%20CO%20levels%20decreased%20due%20to%20a%20reduction%20in%20automotive%20emissions.%20It%20is%20surprising%20that%20atmospheric%20H2%20did%20not%20respond%20similarly%20as%20automotive%20exhaust%20is%20thought%20to%20be%20the%20dominant%20source%20of%20anthropogenic%20H2.%20The%20monotonic%20late%20twentieth%20century%20rise%20in%20H2%20levels%20is%20consistent%20with%20late%20twentieth-century%20flask%20air%20measurements%20from%20high%20southern%20latitudes.%20An%20additional%20unknown%20source%20of%20H2%20is%20needed%20to%20explain%20twentieth-century%20trends%20in%20atmospheric%20H2%20and%20to%20resolve%20the%20discrepancy%20between%20bottom-up%20and%20top-down%20estimates%20of%20the%20anthropogenic%20source%20term.%20The%20firn%20air-based%20atmospheric%20history%20of%20H2%20provides%20a%20baseline%20from%20which%20to%20assess%20human%20impact%20on%20the%20H2%20cycle%20over%20the%20last%20150%20y%20and%20validate%20models%20that%20will%20be%20used%20to%20project%20future%20trends%20in%20atmospheric%20composition%20as%20H2%20becomes%20a%20more%20common%20energy%20source.%22%2C%22date%22%3A%222021%5C%2F09%22%2C%22language%22%3A%22English%22%2C%22DOI%22%3A%2210.1073%5C%2Fpnas.2103335118%22%2C%22ISSN%22%3A%220027-8424%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A17Z%22%7D%7D%2C%7B%22key%22%3A%22CDG25C4Q%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Goodge%20et%20al.%22%2C%22parsedDate%22%3A%222021-09%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EGoodge%2C%20J.%20W.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20Johnson%2C%20J.%2C%20Tosi%2C%20D.%2C%20%26amp%3B%20Bay%2C%20R.%20%282021%29.%20Deep%20ice%20drilling%2C%20bedrock%20coring%20and%20dust%20logging%20with%20the%20Rapid%20Access%20Ice%20Drill%20%28RAID%29%20at%20Minna%20Bluff%2C%20Antarctica.%20%3Ci%3EAnnals%20of%20Glaciology%3C%5C%2Fi%3E%2C%20%3Ci%3E62%3C%5C%2Fi%3E%2885%26%23x2013%3B86%29%2C%20324%26%23x2013%3B339.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1017%5C%2Faog.2021.13%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1017%5C%2Faog.2021.13%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Deep%20ice%20drilling%2C%20bedrock%20coring%20and%20dust%20logging%20with%20the%20Rapid%20Access%20Ice%20Drill%20%28RAID%29%20at%20Minna%20Bluff%2C%20Antarctica%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20W.%22%2C%22lastName%22%3A%22Goodge%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Johnson%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22D.%22%2C%22lastName%22%3A%22Tosi%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%22%2C%22lastName%22%3A%22Bay%22%7D%5D%2C%22abstractNote%22%3A%22Rapid%20Access%20Ice%20Drill%20is%20a%20new%20drilling%20technology%20capable%20of%20quickly%20accessing%20the%20glacial%20bed%20of%20Antarctic%20ice%20sheets%2C%20retrieving%20ice%20core%20and%20rock%20core%20samples%2C%20and%20providing%20boreholes%20for%20downhole%20logging%20of%20physical%20properties.%20Scientific%20goals%20include%20searching%20for%20old%20ice%20near%20the%20glacial%20bed%20and%20sampling%20subglacial%20bedrock.%20During%20field%20trials%20near%20McMurdo%20Station%20on%20a%20piedmont%20glacier%20at%20Minna%20Bluff%20in%20the%202019-20%20austral%20summer%2C%20we%20successfully%20completed%20a%20%27top-to-bottom%27%20operational%20sequence%20in%20three%20boreholes%20by%20%281%29%20augering%20through%20firn%2C%20%282%29%20creating%20a%20borehole%20packer%20seal%20in%20non-porous%20ice%2C%20%283%29%20establishing%20fluid%20circulation%2C%20%284%29%20quickly%20drilling%20a%20borehole%20in%20ice%20at%20penetration%20rates%20up%20to%201.2mmin-1%2C%20%285%29%20acquiring%20a%20short%20ice%20core%20at%20depth%2C%20%286%29%20penetrating%20the%20glacial%20bed%20at%20a%20depth%20of%20similar%20to%20677%20m%2C%20%287%29%20recovering%20a%203.2m%20core%20of%20ice%2C%20basal%20till%20and%20subglacial%20bedrock%2C%20%288%29%20optically%20logging%20the%20borehole%20on%20wireline%2C%20%289%29%20testing%20hydrofracture%20potential%20by%20overpressuring%20the%20borehole%20fluid%20and%20%2810%29%20operating%20in%20an%20environmentally%20benign%20yet%20rapid%20field%20mode.%20Minna%20Bluff%20testing%2C%20therefore%2C%20demonstrates%20the%20effectiveness%20of%20this%20integrated%20system%20to%20drill%20rapidly%20through%20thick%20ice%20and%20penetrate%20across%20the%20glacial%20bed%20to%20take%20cores%20of%20bedrock.%22%2C%22date%22%3A%222021%5C%2F09%22%2C%22language%22%3A%22English%22%2C%22DOI%22%3A%2210.1017%5C%2Faog.2021.13%22%2C%22ISSN%22%3A%220260-3055%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A15Z%22%7D%7D%2C%7B%22key%22%3A%223ANXG7CB%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22He%20et%20al.%22%2C%22parsedDate%22%3A%222021-06%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EHe%2C%20C.%20F.%2C%20Liu%2C%20Z.%20Y.%2C%20Otto-Bliesner%2C%20B.%20L.%2C%20Brady%2C%20E.%20C.%2C%20Zhu%2C%20C.%20Y.%2C%20Tomas%2C%20R.%2C%20Buizert%2C%20C.%2C%20%26amp%3B%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%20%282021%29.%20Abrupt%20Heinrich%20Stadial%201%20cooling%20missing%20in%20Greenland%20oxygen%20isotopes.%20%3Ci%3EScience%20Advances%3C%5C%2Fi%3E%2C%20%3Ci%3E7%3C%5C%2Fi%3E%2825%29.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1126%5C%2Fsciadv.abh1007%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1126%5C%2Fsciadv.abh1007%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Abrupt%20Heinrich%20Stadial%201%20cooling%20missing%20in%20Greenland%20oxygen%20isotopes%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%20F.%22%2C%22lastName%22%3A%22He%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Z.%20Y.%22%2C%22lastName%22%3A%22Liu%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22B.%20L.%22%2C%22lastName%22%3A%22Otto-Bliesner%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20C.%22%2C%22lastName%22%3A%22Brady%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%20Y.%22%2C%22lastName%22%3A%22Zhu%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%22%2C%22lastName%22%3A%22Tomas%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%22%2C%22lastName%22%3A%22Buizert%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%5D%2C%22abstractNote%22%3A%22Abrupt%20climate%20changes%20during%20the%20last%20deglaciation%20have%20been%20well%20preserved%20in%20proxy%20records%20across%20the%20globe.%20However%2C%20one%20long-standing%20puzzle%20is%20the%20apparent%20absence%20of%20the%20onset%20of%20the%20Heinrich%20Stadial%201%20%28HS1%29%20cold%20event%20around%2018%20ka%20in%20Greenland%20ice%20core%20oxygen%20isotope%20delta%20O-18%20records%2C%20inconsistent%20with%20other%20proxies.%20Here%2C%20combining%20proxy%20records%20with%20an%20isotope-enabled%20transient%20deglacial%20simulation%2C%20we%20propose%20that%20a%20substantial%20HS1%20cooling%20onset%20did%20indeed%20occur%20over%20the%20Arctic%20in%20winter.%20However%2C%20this%20cooling%20signal%20in%20the%20depleted%20oxygen%20isotopic%20composition%20is%20completely%20compensated%20by%20the%20enrichment%20because%20of%20the%20loss%20of%20winter%20precipitation%20in%20response%20to%20sea%20ice%20expansion%20associated%20with%20AMOC%20slowdown%20during%20extreme%20glacial%20climate.%20In%20contrast%2C%20the%20Arctic%20summer%20warmed%20during%20HS1%20and%20YD%20because%20of%20increased%20insolation%20and%20greenhouse%20gases%2C%20consistent%20with%20snowline%20reconstructions.%20Our%20work%20suggests%20that%20Greenland%20delta%20O-18%20may%20substantially%20underestimate%20temperature%20variability%20during%20cold%20glacial%20conditions.%22%2C%22date%22%3A%222021%5C%2F06%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.1126%5C%2Fsciadv.abh1007%22%2C%22ISSN%22%3A%222375-2548%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A14Z%22%7D%7D%2C%7B%22key%22%3A%22R4ZRDQ7P%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Buizert%20et%20al.%22%2C%22parsedDate%22%3A%222021-06%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EBuizert%2C%20C.%2C%20Fudge%2C%20T.%20J.%2C%20Roberts%2C%20W.%20H.%20G.%2C%20Steig%2C%20E.%20J.%2C%20Sherriff-Tadano%2C%20S.%2C%20Ritz%2C%20C.%2C%20Lefebvre%2C%20E.%2C%20Edwards%2C%20J.%2C%20Kawamura%2C%20K.%2C%20Oyabu%2C%20I.%2C%20Motoyama%2C%20H.%2C%20Kahle%2C%20E.%20C.%2C%20Jones%2C%20T.%20R.%2C%20Abe-Ouchi%2C%20A.%2C%20Obase%2C%20T.%2C%20Martin%2C%20C.%2C%20Corr%2C%20H.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20Beaudette%2C%20R.%2C%20%26%23x2026%3B%20Schwander%2C%20J.%20%282021%29.%20Antarctic%20surface%20temperature%20and%20elevation%20during%20the%20Last%20Glacial%20Maximum.%20%3Ci%3EScience%3C%5C%2Fi%3E%2C%20%3Ci%3E372%3C%5C%2Fi%3E%286546%29%2C%201097-%2B.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1126%5C%2Fscience.abd2897%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1126%5C%2Fscience.abd2897%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Antarctic%20surface%20temperature%20and%20elevation%20during%20the%20Last%20Glacial%20Maximum%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%22%2C%22lastName%22%3A%22Buizert%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%20J.%22%2C%22lastName%22%3A%22Fudge%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22W.%20H.%20G.%22%2C%22lastName%22%3A%22Roberts%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20J.%22%2C%22lastName%22%3A%22Steig%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%22%2C%22lastName%22%3A%22Sherriff-Tadano%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%22%2C%22lastName%22%3A%22Ritz%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%22%2C%22lastName%22%3A%22Lefebvre%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Edwards%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22K.%22%2C%22lastName%22%3A%22Kawamura%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22I.%22%2C%22lastName%22%3A%22Oyabu%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22H.%22%2C%22lastName%22%3A%22Motoyama%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20C.%22%2C%22lastName%22%3A%22Kahle%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%20R.%22%2C%22lastName%22%3A%22Jones%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%22%2C%22lastName%22%3A%22Abe-Ouchi%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%22%2C%22lastName%22%3A%22Obase%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%22%2C%22lastName%22%3A%22Martin%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22H.%22%2C%22lastName%22%3A%22Corr%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%22%2C%22lastName%22%3A%22Beaudette%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20A.%22%2C%22lastName%22%3A%22Epifanio%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20J.%22%2C%22lastName%22%3A%22Brook%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22K.%22%2C%22lastName%22%3A%22Martin%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Chappellaz%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%22%2C%22lastName%22%3A%22Aoki%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%22%2C%22lastName%22%3A%22Nakazawa%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%20A.%22%2C%22lastName%22%3A%22Sowers%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%20B.%22%2C%22lastName%22%3A%22Alley%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Ahn%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Sigl%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Severi%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22N.%20W.%22%2C%22lastName%22%3A%22Dunbar%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%22%2C%22lastName%22%3A%22Svensson%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20M.%22%2C%22lastName%22%3A%22Fegyveresi%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%20F.%22%2C%22lastName%22%3A%22He%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Z.%20Y.%22%2C%22lastName%22%3A%22Liu%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Zhu%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22B.%20L.%22%2C%22lastName%22%3A%22Otto-Bliesner%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22V.%20Y.%22%2C%22lastName%22%3A%22Lipenkov%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Kageyama%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Schwander%22%7D%5D%2C%22abstractNote%22%3A%22Water-stable%20isotopes%20in%20polar%20ice%20cores%20are%20a%20widely%20used%20temperature%20proxy%20in%20paleoclimate%20reconstruction%2C%20yet%20calibration%20remains%20challenging%20in%20East%20Antarctica.%20Here%2C%20we%20reconstruct%20the%20magnitude%20and%20spatial%20pattern%20of%20Last%20Glacial%20Maximum%20surface%20cooling%20in%20Antarctica%20using%20borehole%20thermometry%20and%20firn%20properties%20in%20seven%20ice%20cores.%20West%20Antarctic%20sites%20cooled%20similar%20to%2010%20degrees%20C%20relative%20to%20the%20preindustrial%20period.%20East%20Antarctic%20sites%20show%20a%20range%20from%20similar%20to%204%20degrees%20to%20similar%20to%207%20degrees%20C%20cooling%2C%20which%20is%20consistent%20with%20the%20results%20of%20global%20climate%20models%20when%20the%20effects%20of%20topographic%20changes%20indicated%20with%20ice%20core%20air-content%20data%20are%20included%2C%20but%20less%20than%20those%20indicated%20with%20the%20use%20of%20water-stable%20isotopes%20calibrated%20against%20modern%20spatial%20gradients.%20An%20altered%20Antarctic%20temperature%20inversion%20during%20the%20glacial%20reconciles%20our%20estimates%20with%20water-isotope%20observations.%22%2C%22date%22%3A%222021%5C%2F06%22%2C%22language%22%3A%22English%22%2C%22DOI%22%3A%2210.1126%5C%2Fscience.abd2897%22%2C%22ISSN%22%3A%220036-8075%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A14Z%22%7D%7D%2C%7B%22key%22%3A%22RG93TE4M%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Seltzer%20et%20al.%22%2C%22parsedDate%22%3A%222021-05%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3ESeltzer%2C%20A.%20M.%2C%20Ng%2C%20J.%2C%20Aeschbach%2C%20W.%2C%20Kipfer%2C%20R.%2C%20Kulongoski%2C%20J.%20T.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20%26amp%3B%20Stute%2C%20M.%20%282021%29.%20Widespread%20six%20degrees%20Celsius%20cooling%20on%20land%20during%20the%20Last%20Glacial%20Maximum.%20%3Ci%3ENature%3C%5C%2Fi%3E%2C%20%3Ci%3E593%3C%5C%2Fi%3E%287858%29%2C%20228-%2B.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1038%5C%2Fs41586-021-03467-6%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1038%5C%2Fs41586-021-03467-6%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Widespread%20six%20degrees%20Celsius%20cooling%20on%20land%20during%20the%20Last%20Glacial%20Maximum%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%20M.%22%2C%22lastName%22%3A%22Seltzer%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Ng%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22W.%22%2C%22lastName%22%3A%22Aeschbach%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%22%2C%22lastName%22%3A%22Kipfer%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20T.%22%2C%22lastName%22%3A%22Kulongoski%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Stute%22%7D%5D%2C%22abstractNote%22%3A%22The%20magnitude%20of%20global%20cooling%20during%20the%20Last%20Glacial%20Maximum%20%28LGM%2C%20the%20coldest%20multimillennial%20interval%20of%20the%20last%20glacial%20period%29%20is%20an%20important%20constraint%20for%20evaluating%20estimates%20of%20Earth%27s%20climate%20sensitivity%281%2C2%29.%20Reliable%20LGM%20temperatures%20come%20from%20high-latitude%20ice%20cores%283%2C4%29%2C%20but%20substantial%20disagreement%20exists%20between%20proxy%20records%20in%20the%20low%20latitudes%281%2C5-8%29%2C%20where%20quantitative%20low-elevation%20records%20on%20land%20are%20scarce.%20Filling%20this%20data%20gap%2C%20noble%20gases%20in%20ancient%20groundwater%20record%20past%20land%20surface%20temperatures%20through%20a%20direct%20physical%20relationship%20that%20is%20rooted%20in%20their%20temperature-dependent%20solubility%20in%20water%289%2C10%29.%20Dissolved%20noble%20gases%20are%20suitable%20tracers%20of%20LGM%20temperature%20because%20of%20their%20complete%20insensitivity%20to%20biological%20and%20chemical%20processes%20and%20the%20ubiquity%20of%20LGM-aged%20groundwater%20around%20the%20globe%2811%2C12%29.%20However%2C%20although%20several%20individual%20noble%20gas%20studies%20have%20found%20substantial%20tropical%20LGM%20cooling%2813-16%29%2C%20they%20have%20used%20different%20methodologies%20and%20provide%20limited%20spatial%20coverage.%20Here%20we%20use%20noble%20gases%20in%20groundwater%20to%20show%20that%20the%20low-altitude%2C%20low-to-mid-latitude%20land%20surface%20%2845%20degrees%20south%20to%2035%20degrees%20north%29%20cooled%20by%205.8%20%2B%5C%2F-%200.6%20degrees%20Celsius%20%28mean%20%2B%5C%2F-%2095%25%20confidence%20interval%29%20during%20the%20LGM.%20Our%20analysis%20includes%20four%20decades%20of%20groundwater%20noble%20gas%20data%20from%20six%20continents%2C%20along%20with%20new%20records%20from%20the%20tropics%2C%20all%20of%20which%20were%20interpreted%20using%20the%20same%20physical%20framework.%20Our%20land-based%20result%20broadly%20supports%20a%20recent%20reconstruction%20based%20on%20marine%20proxy%20data%20assimilation%281%29%20that%20suggested%20greater%20climate%20sensitivity%20than%20previous%20estimates%285-7%29.%20Analyses%20and%20modelling%20of%20noble%20gases%20in%20groundwater%20show%20that%20the%20mean%20annual%20surface%20temperatures%20of%20low-altitude%2C%20low-to-mid-latitude%20land%20masses%20were%20about%206%20degrees%20C%20cooler%20during%20the%20Last%20Glacial%20Maximum%20than%20during%20the%20Late%20Holocene.%22%2C%22date%22%3A%222021%5C%2F05%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.1038%5C%2Fs41586-021-03467-6%22%2C%22ISSN%22%3A%220028-0836%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A23Z%22%7D%7D%2C%7B%22key%22%3A%22PQJBXRGK%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Birner%20et%20al.%22%2C%22parsedDate%22%3A%222021-03%22%2C%22numChildren%22%3A4%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EBirner%2C%20B.%2C%20Paplawsky%2C%20W.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%2C%20%26amp%3B%20Keeling%2C%20R.%20F.%20%282021%29.%20A%20method%20for%20resolving%20changes%20in%20atmospheric%20He%20%5C%2F%20N-2%20as%20an%20indicator%20of%20fossil%20fuel%20extraction%20and%20stratospheric%20circulation.%20%3Ci%3EAtmospheric%20Measurement%20Techniques%3C%5C%2Fi%3E%2C%20%3Ci%3E14%3C%5C%2Fi%3E%283%29%2C%202515%26%23x2013%3B2527.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Famt-14-2515-2021%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Famt-14-2515-2021%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22A%20method%20for%20resolving%20changes%20in%20atmospheric%20He%20%5C%2F%20N-2%20as%20an%20indicator%20of%20fossil%20fuel%20extraction%20and%20stratospheric%20circulation%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22B.%22%2C%22lastName%22%3A%22Birner%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22W.%22%2C%22lastName%22%3A%22Paplawsky%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%20F.%22%2C%22lastName%22%3A%22Keeling%22%7D%5D%2C%22abstractNote%22%3A%22The%20atmospheric%20He%5C%2FN-2%20ratio%20is%20expected%20to%20increase%20due%20to%20the%20emission%20of%20He%20associated%20with%20fossil%20fuels%20and%20is%20expected%20to%20also%20vary%20in%20both%20space%20and%20time%20due%20to%20gravitational%20separation%20in%20the%20stratosphere.%20These%20signals%20may%20be%20useful%20indicators%20of%20fossil%20fuel%20exploitation%20and%20variability%20in%20stratospheric%20circulation%2C%20but%20direct%20measurements%20of%20He%5C%2FN-2%20ratio%20are%20lacking%20on%20all%20timescales.%20Here%20we%20present%20a%20high-precision%20custom%20inlet%20system%20for%20mass%20spectrometers%20that%20continuously%20stabilizes%20the%20flow%20of%20gas%20during%20sample-standard%20comparison%20and%20removes%20all%20non-noble%20gases%20from%20the%20gas%20stream.%20This%20enables%20unprecedented%20accuracy%20in%20measurement%20of%20relative%20changes%20in%20the%20helium%20mole%20fraction%2C%20which%20can%20be%20directly%20related%20to%20the%20He-4%5C%2FN-2%20ratio%20using%20supplementary%20measurements%20of%20O-2%5C%2FN-2%2C%20Ar%5C%2FN2%20and%20CO2.%20Repeat%20measurements%20of%20the%20same%20combination%20of%20high-pressure%20tanks%20using%20our%20inlet%20system%20achieves%20a%20He%5C%2FN-2%20reproducibility%20of%20similar%20to%2010%20per%20meg%20%28i.e.%2C%200.001%20%25%29%20in%206-8%20h%20analyses.%20This%20compares%20to%20interannual%20changes%20of%20gravitational%20enrichment%20at%20similar%20to%2035%20km%20in%20the%20midlatitude%20stratosphere%20of%20order%20300-400%20per%20meg%20and%20an%20annual%20tropospheric%20increase%20from%20human%20fossil%20fuel%20activity%20of%20less%20than%20similar%20to%2030%20per%20meg%20yr%28-1%29%20%28bounded%20by%20previous%20work%20on%20helium%20isotopes%29.%20The%20gettering%20and%20flow-stabilizing%20inlet%20may%20also%20be%20used%20for%20the%20analysis%20of%20other%20noble-gas%20isotopes%20and%20could%20resolve%20previously%20unobserved%20seasonal%20cycles%20in%20Kr%5C%2FN-2%20and%20Xe%5C%2FN-2.%22%2C%22date%22%3A%222021%5C%2F03%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.5194%5C%2Famt-14-2515-2021%22%2C%22ISSN%22%3A%221867-1381%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22EU5YC9TT%22%2C%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-07-27T16%3A53%3A32Z%22%7D%7D%2C%7B%22key%22%3A%22KQ9L7TV6%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Epifanio%20et%20al.%22%2C%22parsedDate%22%3A%222020-12%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EEpifanio%2C%20J.%20A.%2C%20Brook%2C%20E.%20J.%2C%20Buizert%2C%20C.%2C%20Edwards%2C%20J.%20S.%2C%20Sowers%2C%20T.%20A.%2C%20Kahle%2C%20E.%20C.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20Steig%2C%20E.%20J.%2C%20Winski%2C%20D.%20A.%2C%20Osterberg%2C%20E.%20C.%2C%20Fudge%2C%20T.%20J.%2C%20Aydin%2C%20M.%2C%20Hood%2C%20E.%2C%20Kalk%2C%20M.%2C%20Kreutz%2C%20K.%20J.%2C%20Ferris%2C%20D.%20G.%2C%20%26amp%3B%20Kennedy%2C%20J.%20A.%20%282020%29.%20The%20SP19%20chronology%20for%20the%20South%20Pole%20Ice%20Core%20-%20Part%202%3A%20gas%20chronology%2C%20Eage%2C%20and%20smoothing%20of%20atmospheric%20records.%20%3Ci%3EClimate%20of%20the%20Past%3C%5C%2Fi%3E%2C%20%3Ci%3E16%3C%5C%2Fi%3E%286%29%2C%202431%26%23x2013%3B2444.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Fcp-16-2431-2020%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Fcp-16-2431-2020%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22The%20SP19%20chronology%20for%20the%20South%20Pole%20Ice%20Core%20-%20Part%202%3A%20gas%20chronology%2C%20Eage%2C%20and%20smoothing%20of%20atmospheric%20records%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20A.%22%2C%22lastName%22%3A%22Epifanio%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20J.%22%2C%22lastName%22%3A%22Brook%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%22%2C%22lastName%22%3A%22Buizert%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20S.%22%2C%22lastName%22%3A%22Edwards%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%20A.%22%2C%22lastName%22%3A%22Sowers%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20C.%22%2C%22lastName%22%3A%22Kahle%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20J.%22%2C%22lastName%22%3A%22Steig%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22D.%20A.%22%2C%22lastName%22%3A%22Winski%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20C.%22%2C%22lastName%22%3A%22Osterberg%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%20J.%22%2C%22lastName%22%3A%22Fudge%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Aydin%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%22%2C%22lastName%22%3A%22Hood%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Kalk%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22K.%20J.%22%2C%22lastName%22%3A%22Kreutz%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22D.%20G.%22%2C%22lastName%22%3A%22Ferris%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20A.%22%2C%22lastName%22%3A%22Kennedy%22%7D%5D%2C%22abstractNote%22%3A%22A%20new%20ice%20core%20drilled%20at%20the%20South%20Pole%20provides%20a%2054%20000-year%20paleoenvironmental%20record%20including%20the%20composition%20of%20the%20past%20atmosphere.%20This%20paper%20describes%20the%20SP19%20chronology%20for%20the%20South%20Pole%20atmospheric%20gas%20record%20and%20complements%20a%20previous%20paper%20%28Winski%20et%20al.%2C%202019%29%20describing%20the%20SP19%20ice%20chronology.%20The%20gas%20chronology%20is%20based%20on%20a%20discrete%20methane%20%28CH4%29%20record%20with%2020-%20to%20190-year%20resolution.%20To%20construct%20the%20gas%20timescale%2C%20abrupt%20changes%20in%20atmospheric%20CH4%20during%20the%20glacial%20period%20and%20centennial%20CH4%20variability%20during%20the%20Holocene%20were%20used%20to%20synchronize%20the%20South%20Pole%20gas%20record%20with%20analogous%20data%20from%20the%20West%20Antarctic%20Ice%20Sheet%20Divide%20ice%20core.%20Stratigraphic%20matching%20based%20on%20visual%20optimization%20was%20verified%20using%20an%20automated%20matching%20algorithm.%20The%20South%20Pole%20ice%20core%20recovers%20all%20expected%20changes%20in%20CH4%20based%20on%20previous%20records.%20Gas%20transport%20in%20the%20firn%20results%20in%20smoothing%20of%20the%20atmospheric%20gas%20record%20with%20a%20smoothing%20function%20spectral%20width%20that%20ranges%20from%2030%20to%2078%20years%2C%20equal%20to%203%25%20of%20the%20gas-age-ice-age%20difference%2C%20or%201age.%20The%20new%20gas%20chronology%2C%20in%20combination%20with%20the%20existing%20ice%20age%20scale%20from%20Winski%20et%20al.%20%282019%29%2C%20allows%20a%20model-independent%20reconstruction%20of%20the%20gas-age-ice-%20age%20difference%20through%20the%20whole%20record%2C%20which%20will%20be%20useful%20for%20testing%20firn%20densification%20models.%22%2C%22date%22%3A%222020%5C%2F12%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.5194%5C%2Fcp-16-2431-2020%22%2C%22ISSN%22%3A%221814-9324%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A22Z%22%7D%7D%2C%7B%22key%22%3A%22IYCX2X8U%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Oyabu%20et%20al.%22%2C%22parsedDate%22%3A%222020-12%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EOyabu%2C%20I.%2C%20Kawamura%2C%20K.%2C%20Kitamura%2C%20K.%2C%20Dallmayr%2C%20R.%2C%20Kitamura%2C%20A.%2C%20Sawada%2C%20C.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20Beaudette%2C%20R.%2C%20Orsi%2C%20A.%2C%20Sugawara%2C%20S.%2C%20Ishidoya%2C%20S.%2C%20Dahl-Jensen%2C%20D.%2C%20Goto-Azuma%2C%20K.%2C%20Aoki%2C%20S.%2C%20%26amp%3B%20Nakazawa%2C%20T.%20%282020%29.%20New%20technique%20for%20high-precision%2C%20simultaneous%20measurements%20of%20CH4%2C%20N2O%20and%20CO2%20concentrations%3B%20isotopic%20and%20elemental%20ratios%20of%20N-2%2C%20O-2%20and%20Ar%3B%20and%20total%20air%20content%20in%20ice%20cores%20by%20wet%20extraction.%20%3Ci%3EAtmospheric%20Measurement%20Techniques%3C%5C%2Fi%3E%2C%20%3Ci%3E13%3C%5C%2Fi%3E%2812%29%2C%206703%26%23x2013%3B6731.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Famt-13-6703-2020%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Famt-13-6703-2020%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22New%20technique%20for%20high-precision%2C%20simultaneous%20measurements%20of%20CH4%2C%20N2O%20and%20CO2%20concentrations%3B%20isotopic%20and%20elemental%20ratios%20of%20N-2%2C%20O-2%20and%20Ar%3B%20and%20total%20air%20content%20in%20ice%20cores%20by%20wet%20extraction%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22I.%22%2C%22lastName%22%3A%22Oyabu%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22K.%22%2C%22lastName%22%3A%22Kawamura%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22K.%22%2C%22lastName%22%3A%22Kitamura%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%22%2C%22lastName%22%3A%22Dallmayr%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%22%2C%22lastName%22%3A%22Kitamura%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%22%2C%22lastName%22%3A%22Sawada%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%22%2C%22lastName%22%3A%22Beaudette%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%22%2C%22lastName%22%3A%22Orsi%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%22%2C%22lastName%22%3A%22Sugawara%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%22%2C%22lastName%22%3A%22Ishidoya%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22D.%22%2C%22lastName%22%3A%22Dahl-Jensen%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22K.%22%2C%22lastName%22%3A%22Goto-Azuma%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%22%2C%22lastName%22%3A%22Aoki%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%22%2C%22lastName%22%3A%22Nakazawa%22%7D%5D%2C%22abstractNote%22%3A%22Air%20in%20polar%20ice%20cores%20provides%20unique%20information%20on%20past%20climatic%20and%20atmospheric%20changes.%20We%20developed%20a%20new%20method%20combining%20wet%20extraction%2C%20gas%20chromatography%20and%20mass%20spectrometry%20for%20high-precision%2C%20simultaneous%20measurements%20of%20eight%20air%20components%20%28CH4%2C%20N2O%20and%20CO2%20concentrations%3B%20delta%20N-15%2C%20delta%20O-18%2C%20delta%20O-2%5C%2FN-2%20and%20delta%20Ar%5C%2FN-2%3B%20and%20total%20air%20content%29%20from%20an%20ice-core%20sample%20of%20similar%20to%2060%20g.%20The%20ice%20sample%20is%20evacuated%20for%20similar%20to%202%20h%20and%20melted%20under%20vacuum%2C%20and%20the%20released%20air%20is%20continuously%20transferred%20into%20a%20sample%20tube%20at%2010K%20within%2010%20min.%20The%20air%20is%20homogenized%20in%20the%20sample%20tube%20overnight%20at%20room%20temperature%20and%20split%20into%20two%20aliquots%20for%20mass%20spectrometric%20and%20gas%20chromatographic%20measurements.%20Care%20is%20taken%20to%20minimize%20%281%29%20contamination%20of%20greenhouse%20gases%20by%20using%20a%20long%20evacuation%20time%2C%20%282%29%20consumption%20of%20oxygen%20during%20sample%20storage%20by%20a%20passivation%20treatment%20on%20sample%20tubes%2C%20and%20%283%29%20fractionation%20of%20isotopic%20ratios%20with%20a%20long%20homogenization%20time%20for%20splitting.%20Precision%20is%20assessed%20by%20analyzing%20standard%20gases%20with%20artificial%20ice%20and%20duplicate%20measurements%20of%20the%20Dome%20Fuji%20and%20NEEM%20ice%20cores.%20The%20overall%20reproducibility%20%281%20SD%29%20of%20duplicate%20ice-core%20analyses%20are%203.2%20ppb%2C%202.2%20ppb%20and%202.9%20ppm%20for%20CH4%2C%20N2O%20and%20CO2%20concentrations%3B%200.006%20%25%2C%200.011%20%25%2C%200.09%25%20and%200.12%25%20for%20delta%20N-15%2C%20delta%20O-18%2C%20delta%20O-2%5C%2FN-2%20and%20delta%20Ar%5C%2FN-2%3B%20and%200.63mL%28STP%29%20kg%28-1%29%20for%20total%20air%20content%2C%20respectively.%20Our%20new%20method%20successfully%20combines%20the%20high-precision%2C%20small-sample%20and%20multiple-species%20measurements%2C%20with%20a%20wide%20range%20of%20applications%20for%20ice-core%20paleoenviron-mental%20studies.%22%2C%22date%22%3A%222020%5C%2F12%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.5194%5C%2Famt-13-6703-2020%22%2C%22ISSN%22%3A%221867-1381%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A19Z%22%7D%7D%2C%7B%22key%22%3A%22ZITATG4K%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Menking%20et%20al.%22%2C%22parsedDate%22%3A%222020-11%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EMenking%2C%20J.%20A.%2C%20Brook%2C%20E.%20J.%2C%20Schilt%2C%20A.%2C%20Shackleton%2C%20S.%2C%20Dyonisius%2C%20M.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20%26amp%3B%20Petrenko%2C%20V.%20V.%20%282020%29.%20Millennial-scale%20changes%20in%20terrestrial%20and%20marine%20nitrous%20oxide%20emissions%20at%20the%20onset%20and%20termination%20of%20Marine%20Isotope%20Stage%204.%20%3Ci%3EGeophysical%20Research%20Letters%3C%5C%2Fi%3E%2C%20%3Ci%3E47%3C%5C%2Fi%3E%2822%29.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1029%5C%2F2020gl089110%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1029%5C%2F2020gl089110%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Millennial-scale%20changes%20in%20terrestrial%20and%20marine%20nitrous%20oxide%20emissions%20at%20the%20onset%20and%20termination%20of%20Marine%20Isotope%20Stage%204%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20A.%22%2C%22lastName%22%3A%22Menking%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20J.%22%2C%22lastName%22%3A%22Brook%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%22%2C%22lastName%22%3A%22Schilt%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%22%2C%22lastName%22%3A%22Shackleton%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Dyonisius%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22V.%20V.%22%2C%22lastName%22%3A%22Petrenko%22%7D%5D%2C%22abstractNote%22%3A%22Ice%20core%20measurements%20of%20the%20concentration%20and%20stable%20isotopic%20composition%20of%20atmospheric%20nitrous%20oxide%20%28N2O%29%2074%2C000-59%2C000%20years%20ago%20constrain%20marine%20and%20terrestrial%20emissions.%20The%20data%20include%20two%20major%20Dansgaard-Oeschger%20%28D-O%29%20events%20and%20the%20N2O%20decrease%20during%20global%20cooling%20at%20the%20Marine%20Isotope%20Stage%20%28MIS%29%205a-4%20transition.%20The%20N2O%20increase%20associated%20with%20D-O%2019%20%28similar%20to%2073-71.5%20ka%29%20was%20driven%20by%20equal%20contributions%20from%20marine%20and%20terrestrial%20emissions.%20The%20N2O%20decrease%20during%20the%20transition%20into%20MIS%204%20%28similar%20to%2071.5-67.5%20ka%29%20was%20caused%20by%20gradual%20reductions%20of%20similar%20magnitude%20in%20both%20marine%20and%20terrestrial%20sources.%20A%2050%20ppb%20increase%20in%20N2O%20concentration%20at%20the%20end%20of%20MIS%204%20was%20caused%20by%20gradual%20increases%20in%20marine%20and%20terrestrial%20emissions%20between%20similar%20to%2064%20and%2061%20ka%2C%20followed%20by%20an%20abrupt%20increase%20in%20marine%20emissions%20at%20the%20onset%20of%20D-O%2016%5C%2F17%20%2859.5%20ka%29.%20This%20suggests%20that%20the%20importance%20of%20marine%20versus%20terrestrial%20emissions%20in%20controlling%20millennial-scale%20N2O%20fluctuations%20varied%20in%20time.%20Plain%20Language%20Summary%20Nitrous%20oxide%20is%20a%20powerful%20greenhouse%20gas%20that%20is%20produced%20naturally%20in%20soils%20and%20oceans.%20An%20important%20unresolved%20question%20is%20the%20extent%20to%20which%20anthropogenic%20warming%20will%20stimulate%20additional%20emissions%20from%20these%20sources%2C%20further%20adding%20to%20the%20warming.%20Past%20variations%20in%20the%20abundance%20of%20nitrous%20oxide%20have%20been%20observed%20using%20ice%20core%20reconstructions%2C%20but%20the%20reasons%20for%20the%20variations%20are%20not%20well%20understood.%20Nitrous%20oxide%20produced%20in%20soils%20is%20isotopically%20distinct%20from%20nitrous%20oxide%20produced%20in%20oceans.%20New%20measurements%20of%20the%20isotopes%20of%20atmospheric%20nitrous%20oxide%20provide%20constraints%20on%20how%20marine%20and%20terrestrial%20sources%20must%20have%20changed%2C%20driving%20fluctuations%20in%20nitrous%20oxide%20concentration%20during%20two%20intervals%20of%20rapid%20warming%20and%20a%20prolonged%20period%20of%20global%20cooling.%20The%20reconstructed%20changes%20in%20nitrous%20oxide%20sources%20provide%20insights%20into%20relationships%20between%20marine%20and%20terrestrial%20ecosystems%20and%20climate.%22%2C%22date%22%3A%222020%5C%2F11%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.1029%5C%2F2020gl089110%22%2C%22ISSN%22%3A%220094-8276%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A19Z%22%7D%7D%2C%7B%22key%22%3A%229SCXIBFR%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Birner%20et%20al.%22%2C%22parsedDate%22%3A%222020-10%22%2C%22numChildren%22%3A6%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EBirner%2C%20B.%2C%20Chipperfield%2C%20M.%20P.%2C%20Morgan%2C%20E.%20J.%2C%20Stephens%2C%20B.%20B.%2C%20Linz%2C%20M.%2C%20Feng%2C%20W.%20H.%2C%20Wilson%2C%20C.%2C%20Bent%2C%20J.%20D.%2C%20Wofsy%2C%20S.%20C.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%2C%20%26amp%3B%20Keeling%2C%20R.%20F.%20%282020%29.%20Gravitational%20separation%20of%20Ar%5C%2FN-2%20and%20age%20of%20air%20in%20the%20lowermost%20stratosphere%20in%20airborne%20observations%20and%20a%20chemical%20transport%20model.%20%3Ci%3EAtmospheric%20Chemistry%20and%20Physics%3C%5C%2Fi%3E%2C%20%3Ci%3E20%3C%5C%2Fi%3E%2821%29%2C%2012391%26%23x2013%3B12408.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Facp-20-12391-2020%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Facp-20-12391-2020%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Gravitational%20separation%20of%20Ar%5C%2FN-2%20and%20age%20of%20air%20in%20the%20lowermost%20stratosphere%20in%20airborne%20observations%20and%20a%20chemical%20transport%20model%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22B.%22%2C%22lastName%22%3A%22Birner%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%20P.%22%2C%22lastName%22%3A%22Chipperfield%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20J.%22%2C%22lastName%22%3A%22Morgan%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22B.%20B.%22%2C%22lastName%22%3A%22Stephens%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Linz%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22W.%20H.%22%2C%22lastName%22%3A%22Feng%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%22%2C%22lastName%22%3A%22Wilson%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20D.%22%2C%22lastName%22%3A%22Bent%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%20C.%22%2C%22lastName%22%3A%22Wofsy%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%20F.%22%2C%22lastName%22%3A%22Keeling%22%7D%5D%2C%22abstractNote%22%3A%22Accurate%20simulation%20of%20atmospheric%20circulation%2C%20particularly%20in%20the%20lower%20stratosphere%2C%20is%20challenging%20due%20to%20unresolved%20wave-mean%20flow%20interactions%20and%20limited%20high-resolution%20observations%20for%20validation.%20Gravity-induced%20pressure%20gradients%20lead%20to%20a%20small%20but%20measurable%20separation%20of%20heavy%20and%20light%20gases%20by%20molecular%20diffusion%20in%20the%20stratosphere.%20Because%20the%20relative%20abundance%20of%20Ar%20to%20N-2%20is%20exclusively%20controlled%20by%20physical%20transport%2C%20the%20argon-to-nitrogen%20ratio%20%28Ar%5C%2FN-2%29%20provides%20an%20additional%20constraint%20on%20circulation%20and%20the%20age%20of%20air%20%28AoA%29%2C%20i.e.%2C%20the%20time%20elapsed%20since%20entry%20of%20an%20air%20parcel%20into%20the%20stratosphere.%20Here%20we%20use%20airborne%20measurements%20of%20N2O%20and%20Ar%5C%2FN-2%20from%20nine%20campaigns%20with%20global%20coverage%20spanning%202008-2018%20to%20calculate%20AoA%20and%20to%20quantify%20gravitational%20separation%20in%20the%20lowermost%20stratosphere.%20To%20this%20end%2C%20we%20develop%20a%20new%20N2O-AoA%20relationship%20using%20a%20Markov%20chain%20Monte%20Carlo%20algorithm.%20We%20observe%20that%20gravitational%20separation%20increases%20systematically%20with%20increasing%20AoA%20for%20samples%20with%20AoA%20between%200%20and%203%20years.%20These%20observations%20are%20compared%20to%20a%20simulation%20of%20the%20TOMCAT%5C%2FSLIMCAT%203-D%20chemical%20transport%20model%2C%20which%20has%20been%20updated%20to%20include%20gravitational%20fractionation%20of%20gases.%20We%20demonstrate%20that%20although%20AoA%20at%20old%20ages%20is%20slightly%20underestimated%20in%20the%20model%2C%20the%20relationship%20between%20Ar%5C%2FN-2%20and%20AoA%20is%20robust%20and%20agrees%20with%20the%20observations.%20This%20highlights%20the%20potential%20of%20Ar%5C%2FN-2%20to%20become%20a%20new%20AoA%20tracer%20that%20is%20subject%20only%20to%20physical%20transport%20phenomena%20and%20can%20supplement%20the%20suite%20of%20available%20AoA%20indicators.%22%2C%22date%22%3A%222020%5C%2F10%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.5194%5C%2Facp-20-12391-2020%22%2C%22ISSN%22%3A%221680-7316%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22EU5YC9TT%22%2C%22WBZK3IXM%22%2C%22MCXPFWIN%22%5D%2C%22dateModified%22%3A%222022-08-15T16%3A15%3A38Z%22%7D%7D%2C%7B%22key%22%3A%22I9RIAULU%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Cheng%20et%20al.%22%2C%22parsedDate%22%3A%222020-09%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3ECheng%2C%20H.%2C%20Zhang%2C%20H.%20W.%2C%20Spotl%2C%20C.%2C%20Baker%2C%20J.%2C%20Sinha%2C%20A.%2C%20Li%2C%20H.%20Y.%2C%20Bartolome%2C%20M.%2C%20Moreno%2C%20A.%2C%20Kathayat%2C%20G.%2C%20Zhao%2C%20J.%20Y.%2C%20Dong%2C%20X.%20Y.%2C%20Li%2C%20Y.%20W.%2C%20Ning%2C%20Y.%20F.%2C%20Jia%2C%20X.%2C%20Zong%2C%20B.%20Y.%2C%20Brahim%2C%20Y.%20A.%2C%20Perez-Mejias%2C%20C.%2C%20Cai%2C%20Y.%20J.%2C%20Novello%2C%20V.%20F.%2C%20%26%23x2026%3B%20Edwards%2C%20R.%20L.%20%282020%29.%20Timing%20and%20structure%20of%20the%20Younger%20Dryas%20event%20and%20its%20underlying%20climate%20dynamics.%20%3Ci%3EProceedings%20of%20the%20National%20Academy%20of%20Sciences%20of%20the%20United%20States%20of%20America%3C%5C%2Fi%3E%2C%20%3Ci%3E117%3C%5C%2Fi%3E%2838%29%2C%2023408%26%23x2013%3B23417.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1073%5C%2Fpnas.2007869117%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1073%5C%2Fpnas.2007869117%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Timing%20and%20structure%20of%20the%20Younger%20Dryas%20event%20and%20its%20underlying%20climate%20dynamics%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22H.%22%2C%22lastName%22%3A%22Cheng%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22H.%20W.%22%2C%22lastName%22%3A%22Zhang%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%22%2C%22lastName%22%3A%22Spotl%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Baker%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%22%2C%22lastName%22%3A%22Sinha%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22H.%20Y.%22%2C%22lastName%22%3A%22Li%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Bartolome%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%22%2C%22lastName%22%3A%22Moreno%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22G.%22%2C%22lastName%22%3A%22Kathayat%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20Y.%22%2C%22lastName%22%3A%22Zhao%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22X.%20Y.%22%2C%22lastName%22%3A%22Dong%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Y.%20W.%22%2C%22lastName%22%3A%22Li%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Y.%20F.%22%2C%22lastName%22%3A%22Ning%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22X.%22%2C%22lastName%22%3A%22Jia%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22B.%20Y.%22%2C%22lastName%22%3A%22Zong%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Y.%20A.%22%2C%22lastName%22%3A%22Brahim%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%22%2C%22lastName%22%3A%22Perez-Mejias%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Y.%20J.%22%2C%22lastName%22%3A%22Cai%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22V.%20F.%22%2C%22lastName%22%3A%22Novello%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22F.%20W.%22%2C%22lastName%22%3A%22Cruz%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Z.%20S.%22%2C%22lastName%22%3A%22An%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%20L.%22%2C%22lastName%22%3A%22Edwards%22%7D%5D%2C%22abstractNote%22%3A%22The%20Younger%20Dryas%20%28YD%29%2C%20arguably%20the%20most%20widely%20studied%20millennial-scale%20extreme%20climate%20event%2C%20was%20characterized%20by%20diverse%20hydroclimate%20shifts%20globally%20and%20severe%20cooling%20at%20high%20northern%20latitudes%20that%20abruptly%20punctuated%20the%20warming%20trend%20from%20the%20last%20glacial%20to%20the%20present%20interglacial.%20To%20date%2C%20a%20precise%20understanding%20of%20its%20trigger%2C%20propagation%2C%20and%20termination%20remains%20elusive.%20Here%2C%20we%20present%20speleothem%20oxygen-isotope%20data%20that%2C%20in%20concert%20with%20other%20proxy%20records%2C%20allow%20us%20to%20quantify%20the%20timing%20of%20the%20YD%20onset%20and%20termination%20at%20an%20unprecedented%20subcentennial%20temporal%20precision%20across%20the%20North%20Atlantic%2C%20Asian%20Monsoon-Westerlies%2C%20and%20South%20American%20Monsoon%20regions.%20Our%20analysis%20suggests%20that%20the%20onsets%20of%20YD%20in%20the%20North%20Atlantic%20%2812%2C870%20%2B%5C%2F-%2030%20B.P.%29%20and%20the%20Asian%20Monsoon-Westerlies%20region%20are%20essentially%20synchronous%20within%20a%20few%20decades%20and%20lead%20the%20onset%20in%20Antarctica%2C%20implying%20a%20north-to-south%20climate%20signal%20propagation%20via%20both%20atmospheric%20%28decadal-time%20scale%29%20and%20oceanic%20%28centennial-time%20scale%29%20processes%2C%20similar%20to%20the%20Dansgaard-Oeschger%20events%20during%20the%20last%20glacial%20period.%20In%20contrast%2C%20the%20YD%20termination%20may%20have%20started%20first%20in%20Antarctica%20at%20similar%20to%2011%2C900%20B.P.%2C%20or%20perhaps%20even%20earlier%20in%20the%20western%20tropical%20Pacific%2C%20followed%20by%20the%20North%20Atlantic%20between%20similar%20to%2011%2C700%20%2B%5C%2F-%2040%20and%2011%2C610%20%2B%5C%2F-%2040%20B.P.%20These%20observations%20suggest%20that%20the%20initial%20YD%20termination%20might%20have%20originated%20in%20the%20Southern%20Hemisphere%20and%5C%2For%20the%20tropical%20Pacific%2C%20indicating%20a%20Southern%20Hemisphere%5C%2Ftropics%20to%20North%20Atlantic-Asian%20Monsoon-Westerlies%20directionality%20of%20climatic%20recovery.%22%2C%22date%22%3A%222020%5C%2F09%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.1073%5C%2Fpnas.2007869117%22%2C%22ISSN%22%3A%220027-8424%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A22Z%22%7D%7D%2C%7B%22key%22%3A%22ZUS2FZCG%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Lee%20et%20al.%22%2C%22parsedDate%22%3A%222020-09%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3ELee%2C%20J.%20E.%2C%20Brook%2C%20E.%20J.%2C%20Bertler%2C%20N.%20A.%20N.%2C%20Buizert%2C%20C.%2C%20Baisden%2C%20T.%2C%20Blunier%2C%20T.%2C%20Ciobanu%2C%20V.%20G.%2C%20Conway%2C%20H.%2C%20Dahl-Jensen%2C%20D.%2C%20Fudge%2C%20T.%20J.%2C%20Hindmarsh%2C%20R.%2C%20Keller%2C%20E.%20D.%2C%20Parrenin%2C%20F.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20Vallelonga%2C%20P.%2C%20Waddington%2C%20E.%20D.%2C%20%26amp%3B%20Winstrup%2C%20M.%20%282020%29.%20An%2083%2C000-year-old%20ice%20core%20from%20Roosevelt%20Island%2C%20Ross%20Sea%2C%20Antarctica.%20%3Ci%3EClimate%20of%20the%20Past%3C%5C%2Fi%3E%2C%20%3Ci%3E16%3C%5C%2Fi%3E%285%29%2C%201691%26%23x2013%3B1713.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Fcp-16-1691-2020%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Fcp-16-1691-2020%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22An%2083%2C000-year-old%20ice%20core%20from%20Roosevelt%20Island%2C%20Ross%20Sea%2C%20Antarctica%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20E.%22%2C%22lastName%22%3A%22Lee%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20J.%22%2C%22lastName%22%3A%22Brook%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22N.%20A.%20N.%22%2C%22lastName%22%3A%22Bertler%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%22%2C%22lastName%22%3A%22Buizert%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%22%2C%22lastName%22%3A%22Baisden%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%22%2C%22lastName%22%3A%22Blunier%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22V.%20G.%22%2C%22lastName%22%3A%22Ciobanu%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22H.%22%2C%22lastName%22%3A%22Conway%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22D.%22%2C%22lastName%22%3A%22Dahl-Jensen%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%20J.%22%2C%22lastName%22%3A%22Fudge%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%22%2C%22lastName%22%3A%22Hindmarsh%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20D.%22%2C%22lastName%22%3A%22Keller%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22F.%22%2C%22lastName%22%3A%22Parrenin%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22P.%22%2C%22lastName%22%3A%22Vallelonga%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20D.%22%2C%22lastName%22%3A%22Waddington%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Winstrup%22%7D%5D%2C%22abstractNote%22%3A%22In%202013%20an%20ice%20core%20was%20recovered%20from%20Roosevelt%20Island%2C%20an%20ice%20dome%20between%20two%20submarine%20troughs%20carved%20by%20paleo-ice-streams%20in%20the%20Ross%20Sea%2C%20Antarctica.%20The%20ice%20core%20is%20part%20of%20the%20Roosevelt%20Island%20Climate%20Evolution%20%28RICE%29%20project%20and%20provides%20new%20information%20about%20the%20past%20configuration%20of%20the%20West%20Antarctic%20Ice%20Sheet%20%28WAIS%29%20and%20its%20retreat%20during%20the%20last%20deglaciation.%20In%20this%20work%20we%20present%20the%20RICE17%20chronology%2C%20which%20establishes%20the%20depth-age%20relationship%20for%20the%20top%20754m%20of%20the%20763m%20core.%20RICE17%20is%20a%20composite%20chronology%20combining%20annual%20layer%20interpretations%20for%200-343m%20%28Winstrup%20et%20al.%2C%202019%29%20with%20new%20estimates%20for%20gas%20and%20ice%20ages%20based%20on%20synchronization%20of%20CH4%20and%20delta%20O-18%28atm%29%20records%20to%20corresponding%20records%20from%20the%20WAIS%20Divide%20ice%20core%20and%20by%20modeling%20of%20the%20gas%20age-ice%20age%20difference.%20Novel%20aspects%20of%20this%20work%20include%20the%20following%3A%20%281%29%20an%20automated%20algorithm%20for%20multiproxy%20stratigraphic%20synchronization%20of%20high-resolution%20gas%20records%3B%20%282%29%20synchronization%20using%20centennial-scale%20variations%20in%20methane%20for%20preanthropogenic%20time%20periods%20%2860-720%20m%2C%201971%20CE%20to%2030%20ka%29%2C%20a%20strategy%20applicable%20for%20future%20ice%20cores%3B%20and%20%283%29%20the%20observation%20of%20a%20continuous%20climate%20record%20back%20to%20similar%20to%2065%20ka%20providing%20evidence%20that%20the%20Roosevelt%20Island%20Ice%20Dome%20was%20a%20constant%20feature%20throughout%20the%20last%20glacial%20period.%22%2C%22date%22%3A%222020%5C%2F09%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.5194%5C%2Fcp-16-1691-2020%22%2C%22ISSN%22%3A%221814-9324%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A14Z%22%7D%7D%2C%7B%22key%22%3A%22M47GQP9T%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Patterson%20et%20al.%22%2C%22parsedDate%22%3A%222020-07%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EPatterson%2C%20J.%20D.%2C%20Aydin%2C%20M.%2C%20Crotwell%2C%20A.%20M.%2C%20Petron%2C%20G.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20%26amp%3B%20Saltzman%2C%20E.%20S.%20%282020%29.%20Atmospheric%20history%20of%20H-2%20over%20the%20past%20century%20reconstructed%20from%20South%20Pole%20firn%20air.%20%3Ci%3EGeophysical%20Research%20Letters%3C%5C%2Fi%3E%2C%20%3Ci%3E47%3C%5C%2Fi%3E%2814%29.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1029%5C%2F2020gl087787%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1029%5C%2F2020gl087787%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Atmospheric%20history%20of%20H-2%20over%20the%20past%20century%20reconstructed%20from%20South%20Pole%20firn%20air%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20D.%22%2C%22lastName%22%3A%22Patterson%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Aydin%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%20M.%22%2C%22lastName%22%3A%22Crotwell%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22G.%22%2C%22lastName%22%3A%22Petron%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20S.%22%2C%22lastName%22%3A%22Saltzman%22%7D%5D%2C%22abstractNote%22%3A%22Molecular%20hydrogen%20%28H-2%29%20is%20an%20abundant%20and%20reactive%20constituent%20of%20Earth%27s%20atmosphere%2C%20with%20links%20to%20climate%20and%20air%20quality.%20Anthropogenic%20emissions%20of%20H-2%20are%20expected%20to%20rise%20as%20the%20use%20of%20H-2%20as%20an%20energy%20source%20increases.%20Documenting%20past%20variations%20in%20atmospheric%20H-2%20will%20help%20to%20validate%20current%20understanding%20of%20the%20global%20H-2%20budget.%20The%20modern%20instrumental%20record%20begins%20in%20the%201980s%3B%20there%20is%20little%20information%20about%20atmospheric%20H-2%20prior%20to%20that%20time.%20Here%2C%20we%20use%20firn%20air%20measurements%20from%20a%202001%20South%20Pole%20campaign%20to%20reconstruct%20atmospheric%20H-2%20levels%20over%20the%2020th%20century.%20Inversion%20of%20the%20measurements%20indicates%20that%20H-2%20over%20South%20Pole%20has%20increased%20from%20350-540%20ppb%20from%201910-2000.%20A%20biogeochemical%20box%20model%20indicates%20that%20the%20atmospheric%20burden%20of%20H-2%20increased%20by%2037%25%20over%20that%20time.%20The%20rise%20in%20H-2%20is%20consistent%20with%20increasing%20H-2%20emissions%20from%20fossil%20fuel%20combustion%20and%20increasing%20atmospheric%20production%20from%20methane%20oxidation.%20Plain%20Language%20Summary%20Hydrogen%20%28H-2%29%20is%20an%20atmospheric%20trace%20gas%20with%20both%20natural%20and%20anthropogenic%20sources.%20In%20the%20atmosphere%2C%20photochemical%20reactions%20of%20H-2%20can%20contribute%20to%20air%20pollution%20and%20influence%20climate.%20Future%20use%20of%20hydrogen%20as%20a%20possible%20replacement%20for%20fossil%20fuels%20will%20likely%20lead%20to%20increased%20emissions%20and%20atmospheric%20levels.%20Here%20we%20use%20measurements%20of%20hydrogen%20in%20South%20Pole%20firn%20air%20to%20reconstruct%20atmospheric%20hydrogen%20levels%20over%20the%2020th%20century.%20We%20find%20that%20atmospheric%20H-2%20increased%20by%20about%2040%25%20over%20that%20time.%20This%20increase%20is%20consistent%20with%20estimates%20of%20emissions%20of%20hydrogen%20and%20hydrogen%20precursors%20from%20fossil%20fuel%20burning.%22%2C%22date%22%3A%222020%5C%2F07%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.1029%5C%2F2020gl087787%22%2C%22ISSN%22%3A%220094-8276%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A15Z%22%7D%7D%2C%7B%22key%22%3A%22XF5XMCFZ%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Dyonisius%20et%20al.%22%2C%22parsedDate%22%3A%222020-02%22%2C%22numChildren%22%3A4%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EDyonisius%2C%20M.%20N.%2C%20Petrenko%2C%20V.%20V.%2C%20Smith%2C%20A.%20M.%2C%20Hua%2C%20Q.%2C%20Yang%2C%20B.%2C%20Schmitt%2C%20J.%2C%20Beck%2C%20J.%2C%20Seth%2C%20B.%2C%20Bock%2C%20M.%2C%20Hmiel%2C%20B.%2C%20Vimont%2C%20I.%2C%20Menking%2C%20J.%20A.%2C%20Shackleton%2C%20S.%20A.%2C%20Baggenstos%2C%20D.%2C%20Bauska%2C%20T.%20K.%2C%20Rhodes%2C%20R.%20H.%2C%20Sperlich%2C%20P.%2C%20Beaudette%2C%20R.%2C%20Harth%2C%20C.%2C%20%26%23x2026%3B%20Weiss%2C%20R.%20F.%20%282020%29.%20Old%20carbon%20reservoirs%20were%20not%20important%20in%20the%20deglacial%20methane%20budget.%20%3Ci%3EScience%3C%5C%2Fi%3E%2C%20%3Ci%3E367%3C%5C%2Fi%3E%286480%29%2C%20907-%2B.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1126%5C%2Fscience.aax0504%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1126%5C%2Fscience.aax0504%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Old%20carbon%20reservoirs%20were%20not%20important%20in%20the%20deglacial%20methane%20budget%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%20N.%22%2C%22lastName%22%3A%22Dyonisius%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22V.%20V.%22%2C%22lastName%22%3A%22Petrenko%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%20M.%22%2C%22lastName%22%3A%22Smith%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Q.%22%2C%22lastName%22%3A%22Hua%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22B.%22%2C%22lastName%22%3A%22Yang%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Schmitt%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Beck%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22B.%22%2C%22lastName%22%3A%22Seth%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Bock%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22B.%22%2C%22lastName%22%3A%22Hmiel%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22I.%22%2C%22lastName%22%3A%22Vimont%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20A.%22%2C%22lastName%22%3A%22Menking%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%20A.%22%2C%22lastName%22%3A%22Shackleton%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22D.%22%2C%22lastName%22%3A%22Baggenstos%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%20K.%22%2C%22lastName%22%3A%22Bauska%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%20H.%22%2C%22lastName%22%3A%22Rhodes%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22P.%22%2C%22lastName%22%3A%22Sperlich%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%22%2C%22lastName%22%3A%22Beaudette%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%22%2C%22lastName%22%3A%22Harth%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Kalk%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20J.%22%2C%22lastName%22%3A%22Brook%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22H.%22%2C%22lastName%22%3A%22Fischer%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%20F.%22%2C%22lastName%22%3A%22Weiss%22%7D%5D%2C%22abstractNote%22%3A%22Permafrost%20and%20methane%20hydrates%20are%20large%2C%20climate-sensitive%20old%20carbon%20reservoirs%20that%20have%20the%20potential%20to%20emit%20large%20quantities%20of%20methane%2C%20a%20potent%20greenhouse%20gas%2C%20as%20the%20Earth%20continues%20to%20warm.%20We%20present%20ice%20core%20isotopic%20measurements%20of%20methane%20%28Delta%20C-14%2C%20delta%20C-13%2C%20and%20delta%20D%29%20from%20the%20last%20deglaciation%2C%20which%20is%20a%20partial%20analog%20for%20modern%20warming.%20Our%20results%20show%20that%20methane%20emissions%20from%20old%20carbon%20reservoirs%20in%20response%20to%20deglacial%20warming%20were%20small%20%28%3C19%20teragrams%20of%20methane%20per%20year%2C%2095%25%20confidence%20interval%29%20and%20argue%20against%20similar%20methane%20emissions%20in%20response%20to%20future%20warming.%20Our%20results%20also%20indicate%20that%20methane%20emissions%20from%20biomass%20burning%20in%20the%20pre-Industrial%20Holocene%20were%2022%20to%2056%20teragrams%20of%20methane%20per%20year%20%2895%25%20confidence%20interval%29%2C%20which%20is%20comparable%20to%20today.%22%2C%22date%22%3A%222020%5C%2F02%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.1126%5C%2Fscience.aax0504%22%2C%22ISSN%22%3A%220036-8075%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%2C%225NFTUH6D%22%5D%2C%22dateModified%22%3A%222022-08-15T18%3A58%3A54Z%22%7D%7D%2C%7B%22key%22%3A%22NYTYUGEY%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Hmiel%20et%20al.%22%2C%22parsedDate%22%3A%222020-02%22%2C%22numChildren%22%3A4%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EHmiel%2C%20B.%2C%20Petrenko%2C%20V.%20V.%2C%20Dyonisius%2C%20M.%20N.%2C%20Buizert%2C%20C.%2C%20Smith%2C%20A.%20M.%2C%20Place%2C%20P.%20F.%2C%20Harth%2C%20C.%2C%20Beaudette%2C%20R.%2C%20Hua%2C%20Q.%2C%20Yang%2C%20B.%2C%20Vimont%2C%20I.%2C%20Michel%2C%20S.%20E.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20Etheridge%2C%20D.%2C%20Bromley%2C%20T.%2C%20Schmitt%2C%20J.%2C%20Fa%3Fn%2C%20X.%2C%20Weiss%2C%20R.%20F.%2C%20%26amp%3B%20Dlugokencky%2C%20E.%20%282020%29.%20Preindustrial%20%28CH4%29-C-14%20indicates%20greater%20anthropogenic%20fossil%20CH4%20emissions.%20%3Ci%3ENature%3C%5C%2Fi%3E%2C%20%3Ci%3E578%3C%5C%2Fi%3E%287795%29%2C%20409-%2B.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1038%5C%2Fs41586-020-1991-8%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1038%5C%2Fs41586-020-1991-8%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Preindustrial%20%28CH4%29-C-14%20indicates%20greater%20anthropogenic%20fossil%20CH4%20emissions%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22B.%22%2C%22lastName%22%3A%22Hmiel%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22V.%20V.%22%2C%22lastName%22%3A%22Petrenko%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%20N.%22%2C%22lastName%22%3A%22Dyonisius%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%22%2C%22lastName%22%3A%22Buizert%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%20M.%22%2C%22lastName%22%3A%22Smith%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22P.%20F.%22%2C%22lastName%22%3A%22Place%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%22%2C%22lastName%22%3A%22Harth%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%22%2C%22lastName%22%3A%22Beaudette%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Q.%22%2C%22lastName%22%3A%22Hua%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22B.%22%2C%22lastName%22%3A%22Yang%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22I.%22%2C%22lastName%22%3A%22Vimont%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%20E.%22%2C%22lastName%22%3A%22Michel%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22D.%22%2C%22lastName%22%3A%22Etheridge%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%22%2C%22lastName%22%3A%22Bromley%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Schmitt%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22X.%22%2C%22lastName%22%3A%22Fa%3Fn%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%20F.%22%2C%22lastName%22%3A%22Weiss%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%22%2C%22lastName%22%3A%22Dlugokencky%22%7D%5D%2C%22abstractNote%22%3A%22Atmospheric%20methane%20%28CH4%29%20is%20a%20potent%20greenhouse%20gas%2C%20and%20its%20mole%20fraction%20has%20more%20than%20doubled%20since%20the%20preindustrial%20era%281%29.%20Fossil%20fuel%20extraction%20and%20use%20are%20among%20the%20largest%20anthropogenic%20sources%20of%20CH4%20emissions%2C%20but%20the%20precise%20magnitude%20of%20these%20contributions%20is%20a%20subject%20of%20debate%282%2C3%29.%20Carbon-14%20in%20CH4%20%28%28CH4%29-C-14%29%20can%20be%20used%20to%20distinguish%20between%20fossil%20%28C-14-free%29%20CH4%20emissions%20and%20contemporaneous%20biogenic%20sources%3B%20however%2C%20poorly%20constrained%20direct%20%28CH4%29-C-14%20emissions%20from%20nuclear%20reactors%20have%20complicated%20this%20approach%20since%20the%20middle%20of%20the%2020th%20century%284%2C5%29.%20Moreover%2C%20the%20partitioning%20of%20total%20fossil%20CH4%20emissions%20%28presently%20172%20to%20195%20teragrams%20CH4%20per%20year%29%282%2C3%29%20between%20anthropogenic%20and%20natural%20geological%20sources%20%28such%20as%20seeps%20and%20mud%20volcanoes%29%20is%20under%20debate%3B%20emission%20inventories%20suggest%20that%20the%20latter%20account%20for%20about%2040%20to%2060%20teragrams%20CH4%20per%20year%286%2C7%29.%20Geological%20emissions%20were%20less%20than%2015.4%20teragrams%20CH4%20per%20year%20at%20the%20end%20of%20the%20Pleistocene%2C%20about%2011%2C600%20years%20ago%288%29%2C%20but%20that%20period%20is%20an%20imperfect%20analogue%20for%20present-day%20emissions%20owing%20to%20the%20large%20terrestrial%20ice%20sheet%20cover%2C%20lower%20sea%20level%20and%20extensive%20permafrost.%20Here%20we%20use%20preindustrial-era%20ice%20core%20%28CH4%29-C-14%20measurements%20to%20show%20that%20natural%20geological%20CH4%20emissions%20to%20the%20atmosphere%20were%20about%201.6%20teragrams%20CH4%20per%20year%2C%20with%20a%20maximum%20of%205.4%20teragrams%20CH4%20per%20year%20%2895%20per%20cent%20confidence%20limit%29-an%20order%20of%20magnitude%20lower%20than%20the%20currently%20used%20estimates.%20This%20result%20indicates%20that%20anthropogenic%20fossil%20CH4%20emissions%20are%20underestimated%20by%20about%2038%20to%2058%20teragrams%20CH4%20per%20year%2C%20or%20about%2025%20to%2040%20per%20cent%20of%20recent%20estimates.%20Our%20record%20highlights%20the%20human%20impact%20on%20the%20atmosphere%20and%20climate%2C%20provides%20a%20firm%20target%20for%20inventories%20of%20the%20global%20CH4%20budget%2C%20and%20will%20help%20to%20inform%20strategies%20for%20targeted%20emission%20reductions%289%2C10%29.%20Isotopic%20evidence%20from%20ice%20cores%20indicates%20that%20preindustrial-era%20geological%20methane%20emissions%20were%20lower%20than%20previously%20thought%2C%20suggesting%20that%20present-day%20emissions%20of%20methane%20from%20fossil%20fuels%20are%20underestimated.%22%2C%22date%22%3A%222020%5C%2F02%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.1038%5C%2Fs41586-020-1991-8%22%2C%22ISSN%22%3A%220028-0836%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%2C%225NFTUH6D%22%5D%2C%22dateModified%22%3A%222022-08-15T17%3A47%3A50Z%22%7D%7D%2C%7B%22key%22%3A%22YYTUD4JP%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Shackleton%20et%20al.%22%2C%22parsedDate%22%3A%222020-01%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EShackleton%2C%20S.%2C%20Baggenstos%2C%20D.%2C%20Menking%2C%20J.%20A.%2C%20Dyonisius%2C%20M.%20N.%2C%20Bereiter%2C%20B.%2C%20Bauska%2C%20T.%20K.%2C%20Rhodes%2C%20R.%20H.%2C%20Brook%2C%20E.%20J.%2C%20Petrenko%2C%20V.%20V.%2C%20McConnell%2C%20J.%20R.%2C%20Kellerhals%2C%20T.%2C%20Haberli%2C%20M.%2C%20Schmitt%2C%20J.%2C%20Fischer%2C%20H.%2C%20%26amp%3B%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%20%282020%29.%20Global%20ocean%20heat%20content%20in%20the%20Last%20Interglacial.%20%3Ci%3ENature%20Geoscience%3C%5C%2Fi%3E%2C%20%3Ci%3E13%3C%5C%2Fi%3E%281%29.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1038%5C%2Fs41561-019-0498-0%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1038%5C%2Fs41561-019-0498-0%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Global%20ocean%20heat%20content%20in%20the%20Last%20Interglacial%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%22%2C%22lastName%22%3A%22Shackleton%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22D.%22%2C%22lastName%22%3A%22Baggenstos%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20A.%22%2C%22lastName%22%3A%22Menking%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%20N.%22%2C%22lastName%22%3A%22Dyonisius%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22B.%22%2C%22lastName%22%3A%22Bereiter%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%20K.%22%2C%22lastName%22%3A%22Bauska%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%20H.%22%2C%22lastName%22%3A%22Rhodes%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20J.%22%2C%22lastName%22%3A%22Brook%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22V.%20V.%22%2C%22lastName%22%3A%22Petrenko%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20R.%22%2C%22lastName%22%3A%22McConnell%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%22%2C%22lastName%22%3A%22Kellerhals%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Haberli%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Schmitt%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22H.%22%2C%22lastName%22%3A%22Fischer%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%5D%2C%22abstractNote%22%3A%22The%20Last%20Interglacial%20%28129-116%20thousand%20years%20ago%20%28ka%29%29%20represents%20one%20of%20the%20warmest%20climate%20intervals%20of%20the%20past%20800%2C000%20years%20and%20the%20most%20recent%20time%20when%20sea%20level%20was%20metres%20higher%20than%20today.%20However%2C%20the%20timing%20and%20magnitude%20of%20the%20peak%20warmth%20varies%20between%20reconstructions%2C%20and%20the%20relative%20importance%20of%20individual%20sources%20that%20contribute%20to%20the%20elevated%20sea%20level%20%28mass%20gain%20versus%20seawater%20expansion%29%20during%20the%20Last%20Interglacial%20remains%20uncertain.%20Here%20we%20present%20the%20first%20mean%20ocean%20temperature%20record%20for%20this%20interval%20from%20noble%20gas%20measurements%20in%20ice%20cores%20and%20constrain%20the%20thermal%20expansion%20contribution%20to%20sea%20level.%20Mean%20ocean%20temperature%20reached%20its%20maximum%20value%20of%201.1%20%2B%5C%2F-%200.3%20degrees%20C%20warmer-than-modern%20values%20at%20the%20end%20of%20the%20penultimate%20deglaciation%20at%20129%20ka%2C%20which%20resulted%20in%200.7%20%2B%5C%2F-%200.3%20m%20of%20thermosteric%20sea-level%20rise%20relative%20to%20present%20level.%20However%2C%20this%20maximum%20in%20ocean%20heat%20content%20was%20a%20transient%20feature%3B%20mean%20ocean%20temperature%20decreased%20in%20the%20first%20several%20thousand%20years%20of%20the%20interglacial%20and%20achieved%20a%20stable%2C%20comparable-to-modern%20value%20by%20similar%20to%20127%20ka.%20The%20synchroneity%20of%20the%20peak%20in%20mean%20ocean%20temperature%20with%20proxy%20records%20of%20abrupt%20transitions%20in%20the%20oceanic%20and%20atmospheric%20circulation%20suggests%20that%20the%20mean%20ocean%20temperature%20maximum%20is%20related%20to%20the%20accumulation%20of%20heat%20in%20the%20ocean%20interior%20during%20the%20preceding%20period%20of%20reduced%20overturning%20circulation.%22%2C%22date%22%3A%222020%5C%2F01%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.1038%5C%2Fs41561-019-0498-0%22%2C%22ISSN%22%3A%221752-0894%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A17Z%22%7D%7D%2C%7B%22key%22%3A%22PNGE29LY%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Seltzer%20et%20al.%22%2C%22parsedDate%22%3A%222019-12%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3ESeltzer%2C%20A.%20M.%2C%20Ng%2C%20J.%2C%20Danskin%2C%20W.%20R.%2C%20Kulongoski%2C%20J.%20T.%2C%20Gannon%2C%20R.%20S.%2C%20Stute%2C%20M.%2C%20%26amp%3B%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%20%282019%29.%20Deglacial%20water-table%20decline%20in%20Southern%20California%20recorded%20by%20noble%20gas%20isotopes.%20%3Ci%3ENature%20Communications%3C%5C%2Fi%3E%2C%20%3Ci%3E10%3C%5C%2Fi%3E.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1038%5C%2Fs41467-019-13693-2%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1038%5C%2Fs41467-019-13693-2%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Deglacial%20water-table%20decline%20in%20Southern%20California%20recorded%20by%20noble%20gas%20isotopes%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%20M.%22%2C%22lastName%22%3A%22Seltzer%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Ng%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22W.%20R.%22%2C%22lastName%22%3A%22Danskin%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20T.%22%2C%22lastName%22%3A%22Kulongoski%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%20S.%22%2C%22lastName%22%3A%22Gannon%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Stute%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%5D%2C%22abstractNote%22%3A%22Constraining%20the%20magnitude%20of%20past%20hydrological%20change%20may%20improve%20understanding%20and%20predictions%20of%20future%20shifts%20in%20water%20availability.%20Here%20we%20demonstrate%20that%20water-table%20depth%2C%20a%20sensitive%20indicator%20of%20hydroclimate%2C%20can%20be%20quantitatively%20reconstructed%20using%20Kr%20and%20Xe%20isotopes%20in%20groundwater.%20We%20present%20the%20first-ever%20measurements%20of%20these%20dissolved%20noble%20gas%20isotopes%20in%20groundwater%20at%20high%20precision%20%28%3C%3D%200.005%20parts%20per%20thousand%20amu%28-1%29%3B%201%20sigma%29%2C%20which%20reveal%20depth-proportional%20signals%20set%20by%20gravitational%20settling%20in%20soil%20air%20at%20the%20time%20of%20recharge.%20Analyses%20of%20California%20groundwater%20successfully%20reproduce%20modern%20groundwater%20levels%20and%20indicate%20a%2017.9%20%2B%5C%2F-%201.3%20m%20%28%2B%5C%2F-%201%20SE%29%20decline%20in%20water-table%20depth%20in%20Southern%20California%20during%20the%20last%20deglaciation.%20This%20hydroclimatic%20transition%20from%20the%20wetter%20glacial%20period%20to%20more%20arid%20Holocene%20accompanies%20a%20surface%20warming%20of%206.2%20%2B%5C%2F-%200.6%20degrees%20C%20%28%2B%5C%2F-%201%20SE%29.%20This%20new%20hydroclimate%20proxy%20builds%20upon%20an%20existing%20paleo-temperature%20application%20of%20noble%20gases%20and%20may%20identify%20regions%20prone%20to%20future%20hydrological%20change.%22%2C%22date%22%3A%222019%5C%2F12%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.1038%5C%2Fs41467-019-13693-2%22%2C%22ISSN%22%3A%222041-1723%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A16Z%22%7D%7D%2C%7B%22key%22%3A%22PBDADP4K%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Yan%20et%20al.%22%2C%22parsedDate%22%3A%222019-10%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EYan%2C%20Y.%20Z.%2C%20Bender%2C%20M.%20L.%2C%20Brook%2C%20E.%20J.%2C%20Clifford%2C%20H.%20M.%2C%20Kemeny%2C%20P.%20C.%2C%20Kurbatov%2C%20A.%20V.%2C%20Mackay%2C%20S.%2C%20Mayewski%2C%20P.%20A.%2C%20Ng%2C%20J.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20%26amp%3B%20Higgins%2C%20J.%20A.%20%282019%29.%20Two-million-year-old%20snapshots%20of%20atmospheric%20gases%20from%20Antarctic%20ice.%20%3Ci%3ENature%3C%5C%2Fi%3E%2C%20%3Ci%3E574%3C%5C%2Fi%3E%287780%29%2C%20663-%2B.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1038%5C%2Fs41586-019-1692-3%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1038%5C%2Fs41586-019-1692-3%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Two-million-year-old%20snapshots%20of%20atmospheric%20gases%20from%20Antarctic%20ice%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Y.%20Z.%22%2C%22lastName%22%3A%22Yan%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%20L.%22%2C%22lastName%22%3A%22Bender%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20J.%22%2C%22lastName%22%3A%22Brook%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22H.%20M.%22%2C%22lastName%22%3A%22Clifford%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22P.%20C.%22%2C%22lastName%22%3A%22Kemeny%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%20V.%22%2C%22lastName%22%3A%22Kurbatov%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%22%2C%22lastName%22%3A%22Mackay%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22P.%20A.%22%2C%22lastName%22%3A%22Mayewski%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Ng%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20A.%22%2C%22lastName%22%3A%22Higgins%22%7D%5D%2C%22abstractNote%22%3A%22Over%20the%20past%20eight%20hundred%20thousand%20years%2C%20glacial-interglacial%20cycles%20oscillated%20with%20a%20period%20of%20one%20hundred%20thousand%20years%20%28%27100k%20world%271%29.%20Ice%20core%20and%20ocean%20sediment%20data%20have%20shown%20that%20atmospheric%20carbon%20dioxide%2C%20Antarctic%20temperature%2C%20deep%20ocean%20temperature%2C%20and%20global%20ice%20volume%20correlated%20strongly%20with%20each%20other%20in%20the%20100k%20world%282-6%29.%20Between%20about%202.8%20and%201.2%20million%20years%20ago%2C%20glacial%20cycles%20were%20smaller%20in%20magnitude%20and%20shorter%20in%20duration%20%28%2740k%20world%277%29.%20Proxy%20data%20from%20deep-sea%20sediments%20suggest%20that%20the%20variability%20of%20atmospheric%20carbon%20dioxide%20in%20the%2040k%20world%20was%20also%20lower%20than%20in%20the%20100k%20world%288-10%29%2C%20but%20we%20do%20not%20have%20direct%20observations%20of%20atmospheric%20greenhouse%20gases%20from%20this%20period.%20Here%20we%20report%20the%20recovery%20of%20stratigraphically%20discontinuous%20ice%20more%20than%20two%20million%20years%20old%20from%20the%20Allan%20Hills%20Blue%20Ice%20Area%2C%20East%20Antarctica.%20Concentrations%20of%20carbon%20dioxide%20and%20methane%20in%20ice%20core%20samples%20older%20than%20two%20million%20years%20have%20been%20altered%20by%20respiration%2C%20but%20some%20younger%20samples%20are%20pristine.%20The%20recovered%20ice%20cores%20extend%20direct%20observations%20of%20atmospheric%20carbon%20dioxide%2C%20methane%2C%20and%20Antarctic%20temperature%20%28based%20on%20the%20deuterium%5C%2Fhydrogen%20isotope%20ratio%20delta%20D-ice%2C%20a%20proxy%20for%20regional%20temperature%29%20into%20the%2040k%20world.%20All%20climate%20properties%20before%20eight%20hundred%20thousand%20years%20ago%20fall%20within%20the%20envelope%20of%20observations%20from%20continuous%20deep%20Antarctic%20ice%20cores%20that%20characterize%20the%20100k%20world.%20However%2C%20the%20lowest%20measured%20carbon%20dioxide%20and%20methane%20concentrations%20and%20Antarctic%20temperature%20in%20the%2040k%20world%20are%20well%20above%20glacial%20values%20from%20the%20past%20eight%20hundred%20thousand%20years.%20Our%20results%20confirm%20that%20the%20amplitudes%20of%20glacial-interglacial%20variations%20in%20atmospheric%20greenhouse%20gases%20and%20Antarctic%20climate%20were%20reduced%20in%20the%2040k%20world%2C%20and%20that%20the%20transition%20from%20the%2040k%20to%20the%20100k%20world%20was%20accompanied%20by%20a%20decline%20in%20minimum%20carbon%20dioxide%20concentrations%20during%20glacial%20maxima.%22%2C%22date%22%3A%222019%5C%2F10%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.1038%5C%2Fs41586-019-1692-3%22%2C%22ISSN%22%3A%220028-0836%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A23Z%22%7D%7D%2C%7B%22key%22%3A%22PD7DHU79%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Winski%20et%20al.%22%2C%22parsedDate%22%3A%222019-10%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EWinski%2C%20D.%20A.%2C%20Fudge%2C%20T.%20J.%2C%20Ferris%2C%20D.%20G.%2C%20Osterberg%2C%20E.%20C.%2C%20Fegyveresi%2C%20J.%20M.%2C%20Cole-Dai%2C%20J.%2C%20Thundercloud%2C%20Z.%2C%20Cox%2C%20T.%20S.%2C%20Kreutz%2C%20K.%20J.%2C%20Ortman%2C%20N.%2C%20Buizert%2C%20C.%2C%20Epifanio%2C%20J.%2C%20Brook%2C%20E.%20J.%2C%20Beaudette%2C%20R.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%2C%20Sowers%2C%20T.%2C%20Steig%2C%20E.%20J.%2C%20Kahle%2C%20E.%20C.%2C%20Jones%2C%20T.%20R.%2C%20%26%23x2026%3B%20McConnell%2C%20J.%20R.%20%282019%29.%20The%20SP19%20chronology%20for%20the%20South%20Pole%20Ice%20Core%20-%20Part%201%3A%20volcanic%20matching%20and%20annual%20layer%20counting.%20%3Ci%3EClimate%20of%20the%20Past%3C%5C%2Fi%3E%2C%20%3Ci%3E15%3C%5C%2Fi%3E%285%29%2C%201793%26%23x2013%3B1808.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Fcp-15-1793-2019%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Fcp-15-1793-2019%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22The%20SP19%20chronology%20for%20the%20South%20Pole%20Ice%20Core%20-%20Part%201%3A%20volcanic%20matching%20and%20annual%20layer%20counting%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22D.%20A.%22%2C%22lastName%22%3A%22Winski%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%20J.%22%2C%22lastName%22%3A%22Fudge%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22D.%20G.%22%2C%22lastName%22%3A%22Ferris%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20C.%22%2C%22lastName%22%3A%22Osterberg%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20M.%22%2C%22lastName%22%3A%22Fegyveresi%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Cole-Dai%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22Z.%22%2C%22lastName%22%3A%22Thundercloud%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%20S.%22%2C%22lastName%22%3A%22Cox%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22K.%20J.%22%2C%22lastName%22%3A%22Kreutz%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22N.%22%2C%22lastName%22%3A%22Ortman%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%22%2C%22lastName%22%3A%22Buizert%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Epifanio%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20J.%22%2C%22lastName%22%3A%22Brook%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%22%2C%22lastName%22%3A%22Beaudette%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%22%2C%22lastName%22%3A%22Sowers%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20J.%22%2C%22lastName%22%3A%22Steig%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20C.%22%2C%22lastName%22%3A%22Kahle%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%20R.%22%2C%22lastName%22%3A%22Jones%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22V.%22%2C%22lastName%22%3A%22Morris%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Aydin%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%20R.%22%2C%22lastName%22%3A%22Nicewonger%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22K.%20A.%22%2C%22lastName%22%3A%22Casey%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%20B.%22%2C%22lastName%22%3A%22Alley%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20D.%22%2C%22lastName%22%3A%22Waddington%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22N.%20A.%22%2C%22lastName%22%3A%22Iverson%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22N.%20W.%22%2C%22lastName%22%3A%22Dunbar%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%20C.%22%2C%22lastName%22%3A%22Bay%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20M.%22%2C%22lastName%22%3A%22Souney%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Sigl%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20R.%22%2C%22lastName%22%3A%22McConnell%22%7D%5D%2C%22abstractNote%22%3A%22The%20South%20Pole%20Ice%20Core%20%28SPICEcore%29%20was%20drilled%20in%202014-2016%20to%20provide%20a%20detailed%20multi-proxy%20archive%20of%20paleoclimate%20conditions%20in%20East%20Antarctica%20during%20the%20Holocene%20and%20late%20Pleistocene.%20Interpretation%20of%20these%20records%20requires%20an%20accurate%20depth-age%20relationship.%20Here%2C%20we%20present%20the%20SPICEcore%20%28SP19%29%20timescale%20for%20the%20age%20of%20the%20ice%20of%20SPICEcore.%20SP19%20is%20synchronized%20to%20the%20WD2014%20chronology%20from%20theWest%20Antarctic%20Ice%20Sheet%20Divide%20%28WAIS%20Divide%29%20ice%20core%20using%20stratigraphic%20matching%20of%20251%20volcanic%20events.%20These%20events%20indicate%20an%20age%20of%2054%20302%20%2B%5C%2F-%20519%20BP%20%28years%20before%201950%29%20at%20the%20bottom%20of%20SPICEcore.%20Annual%20layers%20identified%20in%20sodium%20and%20magnesium%20ions%20to%2011%20341%20BP%20were%20used%20to%20interpolate%20between%20stratigraphic%20volcanic%20tie%20points%2C%20yielding%20an%20annually%20resolved%20chronology%20through%20the%20Holocene.%20Estimated%20timescale%20uncertainty%20during%20the%20Holocene%20is%20less%20than%2018%20years%20relative%20to%20WD2014%2C%20with%20the%20exception%20of%20the%20interval%20between%201800%20to%203100%20BP%20when%20uncertainty%20estimates%20reach%20%2B%5C%2F-%2025%20years%20due%20to%20widely%20spaced%20volcanic%20tie%20points.%20Prior%20to%20the%20Holocene%2C%20uncertainties%20remain%20within%20124%20years%20relative%20to%20WD2014.%20Results%20show%20an%20average%20Holocene%20accumulation%20rate%20of%207.4%20cm%20yr%28-1%29%20%28water%20equivalent%29.%20The%20time%20variability%20of%20accumulation%20rate%20is%20consistent%20with%20expectations%20for%20steady-state%20ice%20flow%20through%20the%20modern%20spatial%20pattern%20of%20accumulation%20rate.%20Time%20variations%20in%20nitrate%20concentration%2C%20nitrate%20seasonal%20amplitude%20and%20delta%20N-15%20of%20N-2%20in%20turn%20are%20as%20expected%20for%20the%20accumulation%20rate%20variations.%20The%20highly%20variable%20yet%20well-constrained%20Holocene%20accumulation%20history%20at%20the%20site%20can%20help%20improve%20scientific%20understanding%20of%20deposition-sensitive%20climate%20proxies%20such%20as%20delta%20N-15%20of%20N-2%20and%20photolyzed%20chemical%20compounds.%22%2C%22date%22%3A%222019%5C%2F10%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.5194%5C%2Fcp-15-1793-2019%22%2C%22ISSN%22%3A%221814-9324%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A22Z%22%7D%7D%2C%7B%22key%22%3A%22NT8J64K6%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22M%5Cu00fchle%20et%20al.%22%2C%22parsedDate%22%3A%222019-08%22%2C%22numChildren%22%3A6%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EM%26%23xFC%3Bhle%2C%20J.%2C%20Trudinger%2C%20C.%20M.%2C%20Western%2C%20L.%20M.%2C%20Rigby%2C%20M.%2C%20Vollmer%2C%20M.%20K.%2C%20Park%2C%20S.%2C%20Manning%2C%20A.%20J.%2C%20Say%2C%20D.%2C%20Ganesan%2C%20A.%2C%20Steele%2C%20L.%20P.%2C%20Ivy%2C%20D.%20J.%2C%20Arnold%2C%20T.%2C%20Li%2C%20S.%2C%20Stohl%2C%20A.%2C%20Harth%2C%20C.%20M.%2C%20Salameh%2C%20P.%20K.%2C%20McCulloch%2C%20A.%2C%20O%26%23x2019%3BDoherty%2C%20S.%2C%20Park%2C%20M.%20K.%2C%20%26%23x2026%3B%20Weiss%2C%20R.%20F.%20%282019%29.%20Perfluorocyclobutane%20%28PFC-318%2C%20c-C4F8%29%20in%20the%20global%20atmosphere.%20%3Ci%3EAtmospheric%20Chemistry%20and%20Physics%3C%5C%2Fi%3E%2C%20%3Ci%3E19%3C%5C%2Fi%3E%2815%29%2C%2010335%26%23x2013%3B10359.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Facp-19-10335-2019%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Facp-19-10335-2019%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Perfluorocyclobutane%20%28PFC-318%2C%20c-C4F8%29%20in%20the%20global%20atmosphere%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22M%5Cu00fchle%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%20M.%22%2C%22lastName%22%3A%22Trudinger%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22L.%20M.%22%2C%22lastName%22%3A%22Western%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Rigby%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%20K.%22%2C%22lastName%22%3A%22Vollmer%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%22%2C%22lastName%22%3A%22Park%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%20J.%22%2C%22lastName%22%3A%22Manning%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22D.%22%2C%22lastName%22%3A%22Say%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%22%2C%22lastName%22%3A%22Ganesan%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22L.%20P.%22%2C%22lastName%22%3A%22Steele%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22D.%20J.%22%2C%22lastName%22%3A%22Ivy%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%22%2C%22lastName%22%3A%22Arnold%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%22%2C%22lastName%22%3A%22Li%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%22%2C%22lastName%22%3A%22Stohl%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%20M.%22%2C%22lastName%22%3A%22Harth%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22P.%20K.%22%2C%22lastName%22%3A%22Salameh%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%22%2C%22lastName%22%3A%22McCulloch%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%22%2C%22lastName%22%3A%22O%27Doherty%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%20K.%22%2C%22lastName%22%3A%22Park%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%20O.%22%2C%22lastName%22%3A%22Jo%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22D.%22%2C%22lastName%22%3A%22Young%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22K.%20M.%22%2C%22lastName%22%3A%22Stanley%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22P.%20B.%22%2C%22lastName%22%3A%22Krummel%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22B.%22%2C%22lastName%22%3A%22Mitrevski%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22O.%22%2C%22lastName%22%3A%22Hermansen%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%22%2C%22lastName%22%3A%22Lunder%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22N.%22%2C%22lastName%22%3A%22Evangeliou%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22B.%22%2C%22lastName%22%3A%22Yao%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Kim%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22B.%22%2C%22lastName%22%3A%22Hmiel%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22C.%22%2C%22lastName%22%3A%22Buizert%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22V.%20V.%22%2C%22lastName%22%3A%22Petrenko%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Arduini%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Maione%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22D.%20M.%22%2C%22lastName%22%3A%22Etheridge%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%22%2C%22lastName%22%3A%22Michalopoulou%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Czerniak%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%22%2C%22lastName%22%3A%22Reimann%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22P.%20G.%22%2C%22lastName%22%3A%22Simmonds%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22P.%20J.%22%2C%22lastName%22%3A%22Fraser%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%20G.%22%2C%22lastName%22%3A%22Prinn%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%20F.%22%2C%22lastName%22%3A%22Weiss%22%7D%5D%2C%22abstractNote%22%3A%22We%20reconstruct%20atmospheric%20abundances%20of%20the%20potent%20greenhouse%20gas%20c-C4F8%20%28perfluorocyclobutane%2C%20perfluorocarbon%20PFC-318%29%20from%20measurements%20of%20in%20situ%2C%20archived%2C%20firn%2C%20and%20aircraft%20air%20samples%20with%20precisions%20of%20%5Cu223c1%5Cu2009%25%5Cu20132%5Cu2009%25%20reported%20on%20the%20SIO-14%20gravimetric%20calibration%20scale.%20Combined%20with%20inverse%20methods%2C%20we%20found%20near-zero%20atmospheric%20abundances%20from%20the%20early%201900s%20to%20the%20early%201960s%2C%20after%20which%20they%20rose%20sharply%2C%20reaching%201.66%5Cu2009ppt%20%28parts%20per%20trillion%20dry-air%20mole%20fraction%29%20in%202017.%20Global%20c-C4F8%20emissions%20rose%20from%20near%20zero%20in%20the%201960s%20to%201.2%5Cu00b10.1%20%281%5Cu03c3%29%5Cu2009Gg%5Cu2009yr%5Cu22121%20in%20the%20late%201970s%20to%20late%201980s%2C%20then%20declined%20to%200.77%5Cu00b10.03%5Cu2009Gg%5Cu2009yr%5Cu22121%20in%20the%20mid-1990s%20to%20early%202000s%2C%20followed%20by%20a%20rise%20since%20the%20early%202000s%20to%202.20%5Cu00b10.05%5Cu2009Gg%5Cu2009yr%5Cu22121%20in%202017.%20These%20emissions%20are%20significantly%20larger%20than%20inventory-based%20emission%20estimates.%20Estimated%20emissions%20from%20eastern%20Asia%20rose%20from%200.36%5Cu2009Gg%5Cu2009yr%5Cu22121%20in%202010%20to%200.73%5Cu2009Gg%5Cu2009yr%5Cu22121%20in%202016%20and%202017%2C%2031%5Cu2009%25%20of%20global%20emissions%2C%20mostly%20from%20eastern%20China.%20We%20estimate%20emissions%20of%200.14%5Cu2009Gg%5Cu2009yr%5Cu22121%20from%20northern%20and%20central%20India%20in%202016%20and%20find%20evidence%20for%20significant%20emissions%20from%20Russia.%20In%20contrast%2C%20recent%20emissions%20from%20northwestern%20Europe%20and%20Australia%20are%20estimated%20to%20be%20small%20%28%5Cu22641%5Cu2009%25%20each%29.%20We%20suggest%20that%20emissions%20from%20China%2C%20India%2C%20and%20Russia%20are%20likely%20related%20to%20production%20of%20polytetrafluoroethylene%20%28PTFE%2C%20%5Cu201cTeflon%5Cu201d%29%20and%20other%20fluoropolymers%20and%20fluorochemicals%20that%20are%20based%20on%20the%20pyrolysis%20of%20hydrochlorofluorocarbon%20HCFC-22%20%28CHClF2%29%20in%20which%20c-C4F8%20is%20a%20known%20by-product.%20The%20semiconductor%20sector%2C%20where%20c-C4F8%20is%20used%2C%20is%20estimated%20to%20be%20a%20small%20source%2C%20at%20least%20in%20South%20Korea%2C%20Japan%2C%20Taiwan%2C%20and%20Europe.%20Without%20an%20obvious%20correlation%20with%20population%20density%2C%20incineration%20of%20waste-containing%20fluoropolymers%20is%20probably%20a%20minor%20source%2C%20and%20we%20find%20no%20evidence%20of%20emissions%20from%20electrolytic%20production%20of%20aluminum%20in%20Australia.%20While%20many%20possible%20emissive%20uses%20of%20c-C4F8%20are%20known%20and%20though%20we%20cannot%20categorically%20exclude%20unknown%20sources%2C%20the%20start%20of%20significant%20emissions%20may%20well%20be%20related%20to%20the%20advent%20of%20commercial%20PTFE%20production%20in%201947.%20Process%20controls%20or%20abatement%20to%20reduce%20the%20c-C4F8%20by-product%20were%20probably%20not%20in%20place%20in%20the%20early%20decades%2C%20explaining%20the%20increase%20in%20emissions%20in%20the%201960s%20and%201970s.%20With%20the%20advent%20of%20by-product%20reporting%20requirements%20to%20the%20United%20Nations%20Framework%20Convention%20on%20Climate%20Change%20%28UNFCCC%29%20in%20the%201990s%2C%20concern%20about%20climate%20change%20and%20product%20stewardship%2C%20abatement%2C%20and%20perhaps%20the%20collection%20of%20c-C4F8%20by-product%20for%20use%20in%20the%20semiconductor%20industry%20where%20it%20can%20be%20easily%20abated%2C%20it%20is%20conceivable%20that%20emissions%20in%20developed%20countries%20were%20stabilized%20and%20then%20reduced%2C%20explaining%20the%20observed%20emission%20reduction%20in%20the%201980s%20and%201990s.%20Concurrently%2C%20production%20of%20PTFE%20in%20China%20began%20to%20increase%20rapidly.%20Without%20emission%20reduction%20requirements%2C%20it%20is%20plausible%20that%20global%20emissions%20today%20are%20dominated%20by%20China%20and%20other%20developing%20countries.%20We%20predict%20that%20c-C4F8%20emissions%20will%20continue%20to%20rise%20and%20that%20c-C4F8%20will%20become%20the%20second%20most%20important%20emitted%20PFC%20in%20terms%20of%20CO2-equivalent%20emissions%20within%20a%20year%20or%20two.%20The%202017%20radiative%20forcing%20of%20c-C4F8%20%280.52%5Cu2009mW%5Cu2009m%5Cu22122%29%20is%20small%20but%20emissions%20of%20c-C4F8%20and%20other%20PFCs%2C%20due%20to%20their%20very%20long%20atmospheric%20lifetimes%2C%20essentially%20permanently%20alter%20Earth%27s%20radiative%20budget%20and%20should%20be%20reduced.%20Significant%20emissions%20inferred%20outside%20of%20the%20investigated%20regions%20clearly%20show%20that%20observational%20capabilities%20and%20reporting%20requirements%20need%20to%20be%20improved%20to%20understand%20global%20and%20country-scale%20emissions%20of%20PFCs%20and%20other%20synthetic%20greenhouse%20gases%20and%20ozone-depleting%20substances.%22%2C%22date%22%3A%222019%5C%2F08%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.5194%5C%2Facp-19-10335-2019%22%2C%22ISSN%22%3A%221680-7324%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%2C%225NFTUH6D%22%2C%22VFF5GS5K%22%5D%2C%22dateModified%22%3A%222022-08-15T20%3A17%3A22Z%22%7D%7D%2C%7B%22key%22%3A%22GNW8L77N%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Menking%20et%20al.%22%2C%22parsedDate%22%3A%222019-08%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EMenking%2C%20J.%20A.%2C%20Brook%2C%20E.%20J.%2C%20Shackleton%2C%20S.%20A.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20Dyonisius%2C%20M.%20N.%2C%20Petrenko%2C%20V.%2C%20McConnell%2C%20J.%20R.%2C%20Rhodes%2C%20R.%20H.%2C%20Bauska%2C%20T.%20K.%2C%20Baggenstos%2C%20D.%2C%20Marcott%2C%20S.%2C%20%26amp%3B%20Barker%2C%20S.%20%282019%29.%20Spatial%20pattern%20of%20accumulation%20at%20Taylor%20Dome%20during%20Marine%20Isotope%20Stage%204%3A%20stratigraphic%20constraints%20from%20Taylor%20Glacier.%20%3Ci%3EClimate%20of%20the%20Past%3C%5C%2Fi%3E%2C%20%3Ci%3E15%3C%5C%2Fi%3E%284%29%2C%201537%26%23x2013%3B1556.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Fcp-15-1537-2019%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.5194%5C%2Fcp-15-1537-2019%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Spatial%20pattern%20of%20accumulation%20at%20Taylor%20Dome%20during%20Marine%20Isotope%20Stage%204%3A%20stratigraphic%20constraints%20from%20Taylor%20Glacier%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20A.%22%2C%22lastName%22%3A%22Menking%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20J.%22%2C%22lastName%22%3A%22Brook%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%20A.%22%2C%22lastName%22%3A%22Shackleton%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%20N.%22%2C%22lastName%22%3A%22Dyonisius%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22V.%22%2C%22lastName%22%3A%22Petrenko%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20R.%22%2C%22lastName%22%3A%22McConnell%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%20H.%22%2C%22lastName%22%3A%22Rhodes%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%20K.%22%2C%22lastName%22%3A%22Bauska%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22D.%22%2C%22lastName%22%3A%22Baggenstos%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%22%2C%22lastName%22%3A%22Marcott%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%22%2C%22lastName%22%3A%22Barker%22%7D%5D%2C%22abstractNote%22%3A%22New%20ice%20cores%20retrieved%20from%20the%20Taylor%20Glacier%20%28Antarctica%29%20blue%20ice%20area%20contain%20ice%20and%20air%20spanning%20the%20Marine%20Isotope%20Stage%20%28MIS%29%205-4%20transition%2C%20a%20period%20of%20global%20cooling%20and%20ice%20sheet%20expansion.%20We%20determine%20chronologies%20for%20the%20ice%20and%20air%20bubbles%20in%20the%20new%20ice%20cores%20by%20visually%20matching%20variations%20in%20gas-and%20ice-phase%20tracers%20to%20pre-existing%20ice%20core%20records.%20The%20chronologies%20reveal%20an%20ice%20age-gas%20age%20difference%20%281%20age%29%20approaching%2010%20ka%20during%20MIS%204%2C%20implying%20very%20low%20snow%20accumulation%20in%20the%20Taylor%20Glacier%20accumulation%20zone.%20A%20revised%20chronology%20for%20the%20analogous%20section%20of%20the%20Taylor%20Dome%20ice%20core%20%2884%20to%2055%20ka%29%2C%20located%20to%20the%20south%20of%20the%20Taylor%20Glacier%20accumulation%20zone%2C%20shows%20that%201%20age%20did%20not%20exceed%203%20ka.%20The%20difference%20in%201%20age%20between%20the%20two%20records%20during%20MIS%204%20is%20similar%20in%20magnitude%20but%20opposite%20in%20direction%20to%20what%20is%20observed%20at%20the%20Last%20Glacial%20Maximum.%20This%20relationship%20implies%20that%20a%20spatial%20gradient%20in%20snow%20accumulation%20existed%20across%20the%20Taylor%20Dome%20region%20during%20MIS%204%20that%20was%20oriented%20in%20the%20opposite%20direction%20of%20the%20accumulation%20gradient%20during%20the%20Last%20Glacial%20Maximum.%22%2C%22date%22%3A%222019%5C%2F08%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.5194%5C%2Fcp-15-1537-2019%22%2C%22ISSN%22%3A%221814-9324%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A22Z%22%7D%7D%2C%7B%22key%22%3A%223ECPPQMC%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Seltzer%20et%20al.%22%2C%22parsedDate%22%3A%222019-08%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3ESeltzer%2C%20A.%20M.%2C%20Pavia%2C%20F.%20J.%2C%20Ng%2C%20J.%2C%20%26amp%3B%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%20%282019%29.%20Heavy%20noble%20gas%20isotopes%20as%20new%20constraints%20on%20the%20ventilation%20of%20the%20deep%20ocean.%20%3Ci%3EGeophysical%20Research%20Letters%3C%5C%2Fi%3E%2C%20%3Ci%3E46%3C%5C%2Fi%3E%2815%29%2C%208926%26%23x2013%3B8932.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1029%5C%2F2019gl084089%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1029%5C%2F2019gl084089%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Heavy%20noble%20gas%20isotopes%20as%20new%20constraints%20on%20the%20ventilation%20of%20the%20deep%20ocean%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%20M.%22%2C%22lastName%22%3A%22Seltzer%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22F.%20J.%22%2C%22lastName%22%3A%22Pavia%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Ng%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%5D%2C%22abstractNote%22%3A%22Past%20studies%20of%20noble%20gas%20concentrations%20in%20the%20deep%20ocean%20have%20revealed%20widespread%2C%20several%20percent%20undersaturation%20of%20Ar%2C%20Kr%2C%20and%20Xe.%20However%2C%20the%20physical%20explanation%20for%20these%20disequilibria%20remains%20unclear.%20To%20gain%20insight%20into%20undersaturation%20set%20by%20deep-water%20formation%2C%20we%20measured%20heavy%20noble%20gas%20isotope%20and%20elemental%20ratios%20from%20the%20deep%20North%20Pacific%20using%20a%20new%20analytical%20technique.%20To%20our%20knowledge%2C%20these%20are%20the%20first%20high-precision%20seawater%20profiles%20of%20Ar-38%5C%2FAr-36%20and%20Kr%20and%20Xe%20isotope%20ratios.%20To%20interpret%20isotopic%20disequilibria%2C%20we%20carried%20out%20a%20suite%20of%20laboratory%20experiments%20to%20measure%20solubility%20fractionation%20factors%20in%20seawater.%20In%20the%20deep%20North%20Pacific%2C%20we%20find%20undersaturation%20of%20heavy-to-light%20Ar%20and%20Kr%20isotope%20ratios%2C%20suggesting%20an%20important%20role%20for%20rapid%20cooling-driven%2C%20diffusive%20air-to-sea%20gas%20transport%20in%20setting%20the%20deep-ocean%20undersaturation%20of%20heavy%20noble%20gases.%20These%20isotope%20ratios%20represent%20promising%20new%20constraints%20for%20quantifying%20physical%20air-sea%20gas%20exchange%20processes%2C%20complementing%20noble%20gas%20concentration%20measurements.%20Plain%20Language%20Summary%20The%20deep%20ocean%20inherits%20its%20dissolved%20gas%20content%20from%20exchange%20with%20the%20atmosphere%20at%20high%20latitudes%20and%20from%20biological%20and%20chemical%20processes.%20Noble%20gases%2C%20which%20are%20unaffected%20by%20biology%20and%20chemistry%2C%20are%20useful%20tools%20for%20understanding%20physical%20gas%20exchange.%20Past%20observations%20of%20dissolved%20noble%20gases%20throughout%20the%20deep%20ocean%20have%20revealed%20that%20Ar%2C%20Kr%2C%20and%20Xe%20concentrations%20fall%20below%20expected%20concentrations%20for%20water%20at%20solubility%20equilibrium%20with%20the%20atmosphere.%20However%2C%20a%20physical%20explanation%20for%20this%20well-documented%20undersaturation%20of%20noble%20gases%20remains%20unclear.%20Here%20we%20have%20measured%20the%20isotope%20ratios%20of%20Ar%2C%20Kr%2C%20and%20Xe%20in%20the%20deep%20North%20Pacific%20as%20new%20tools%20to%20investigate%20physical%20mechanisms%20of%20disequilibrium.%20Our%20findings%20suggest%20that%20rapid%20cooling%20and%20sinking%20of%20surface%20water%20at%20high%20latitudes%2C%20driving%20air-to-sea%20gas%20transport%20with%20insufficient%20time%20for%20equilibration%2C%20is%20a%20key%20process%20in%20setting%20the%20observed%20deep-ocean%20undersaturation%20of%20noble%20gases.%22%2C%22date%22%3A%222019%5C%2F08%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.1029%5C%2F2019gl084089%22%2C%22ISSN%22%3A%220094-8276%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A17Z%22%7D%7D%2C%7B%22key%22%3A%22FK59RISC%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Baggenstos%20et%20al.%22%2C%22parsedDate%22%3A%222019-07%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EBaggenstos%2C%20D.%2C%20Haberli%2C%20M.%2C%20Schmitt%2C%20J.%2C%20Shackleton%2C%20S.%20A.%2C%20Birner%2C%20B.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20Kellerhals%2C%20T.%2C%20%26amp%3B%20Fischer%2C%20H.%20%282019%29.%20Earth%26%23x2019%3Bs%20radiative%20imbalance%20from%20the%20Last%20Glacial%20Maximum%20to%20the%20present.%20%3Ci%3EProceedings%20of%20the%20National%20Academy%20of%20Sciences%20of%20the%20United%20States%20of%20America%3C%5C%2Fi%3E%2C%20%3Ci%3E116%3C%5C%2Fi%3E%2830%29%2C%2014881%26%23x2013%3B14886.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1073%5C%2Fpnas.1905447116%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1073%5C%2Fpnas.1905447116%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Earth%27s%20radiative%20imbalance%20from%20the%20Last%20Glacial%20Maximum%20to%20the%20present%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22D.%22%2C%22lastName%22%3A%22Baggenstos%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Haberli%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Schmitt%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%20A.%22%2C%22lastName%22%3A%22Shackleton%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22B.%22%2C%22lastName%22%3A%22Birner%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%22%2C%22lastName%22%3A%22Kellerhals%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22H.%22%2C%22lastName%22%3A%22Fischer%22%7D%5D%2C%22abstractNote%22%3A%22The%20energy%20imbalance%20at%20the%20top%20of%20the%20atmosphere%20determines%20the%20temporal%20evolution%20of%20the%20global%20climate%2C%20and%20vice%20versa%20changes%20in%20the%20climate%20system%20can%20alter%20the%20planetary%20energy%20fluxes.%20This%20interplay%20is%20fundamental%20to%20our%20understanding%20of%20Earth%27s%20heat%20budget%20and%20the%20climate%20system.%20However%2C%20even%20today%2C%20the%20direct%20measurement%20of%20global%20radiative%20fluxes%20is%20difficult%2C%20such%20that%20most%20assessments%20are%20based%20on%20changes%20in%20the%20total%20energy%20content%20of%20the%20climate%20system.%20We%20apply%20the%20same%20approach%20to%20estimate%20the%20long-term%20evolution%20of%20Earth%27s%20radiative%20imbalance%20in%20the%20past.%20New%20measurements%20of%20noble%20gas-derived%20mean%20ocean%20temperature%20from%20the%20European%20Project%20for%20Ice%20Coring%20in%20Antarctica%20Dome%20C%20ice%20core%20covering%20the%20last%2040%2C000%20y%2C%20combined%20with%20recent%20results%20from%20the%20West%20Antarctic%20Ice%20Sheet%20Divide%20ice%20core%20and%20the%20sea-level%20record%2C%20allow%20us%20to%20quantitatively%20reconstruct%20the%20history%20of%20the%20climate%20system%20energy%20budget.%20The%20temporal%20derivative%20of%20this%20quantity%20must%20be%20equal%20to%20the%20planetary%20radiative%20imbalance.%20During%20the%20deglaciation%2C%20a%20positive%20imbalance%20of%20typically%20%2B0.2%20W.m%28-2%29%20is%20maintained%20for%20similar%20to%2010%2C000%20y%2C%20however%2C%20with%20two%20distinct%20peaks%20that%20reach%20up%20to%200.4%20Wm%28-2%29%20during%20times%20of%20substantially%20reduced%20Atlantic%20Meridional%20Overturning%20Circulation.%20We%20conclude%20that%20these%20peaks%20are%20related%20to%20net%20changes%20in%20ocean%20heat%20uptake%2C%20likely%20due%20to%20rapid%20changes%20in%20North%20Atlantic%20deep-water%20formation%20and%20their%20impact%20on%20the%20global%20radiative%20balance%2C%20while%20changes%20in%20cloud%20coverage%2C%20albeit%20uncertain%2C%20may%20also%20factor%20into%20the%20picture.%22%2C%22date%22%3A%222019%5C%2F07%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.1073%5C%2Fpnas.1905447116%22%2C%22ISSN%22%3A%220027-8424%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A16Z%22%7D%7D%2C%7B%22key%22%3A%22PXWCQ3NF%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Seltzer%20et%20al.%22%2C%22parsedDate%22%3A%222019-05%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3ESeltzer%2C%20A.%20M.%2C%20Ng%2C%20J.%2C%20%26amp%3B%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%20%282019%29.%20Precise%20determination%20of%20Ar%2C%20Kr%20and%20Xe%20isotopic%20fractionation%20due%20to%20diffusion%20and%20dissolution%20in%20fresh%20water.%20%3Ci%3EEarth%20and%20Planetary%20Science%20Letters%3C%5C%2Fi%3E%2C%20%3Ci%3E514%3C%5C%2Fi%3E%2C%20156%26%23x2013%3B165.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1016%5C%2Fj.epsl.2019.03.008%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1016%5C%2Fj.epsl.2019.03.008%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Precise%20determination%20of%20Ar%2C%20Kr%20and%20Xe%20isotopic%20fractionation%20due%20to%20diffusion%20and%20dissolution%20in%20fresh%20water%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22A.%20M.%22%2C%22lastName%22%3A%22Seltzer%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%22%2C%22lastName%22%3A%22Ng%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%5D%2C%22abstractNote%22%3A%22Dissolved%20noble%20gases%20are%20ideal%20conservative%20tracers%20of%20physical%20processes%20in%20the%20Earth%20system%20due%20to%20their%20chemical%20and%20biological%20inertness.%20Although%20bulk%20concentrations%20of%20dissolved%20Ar%2C%20Kr%2C%20and%20Xe%20are%20commonly%20measured%20to%20constrain%20physical%20models%20of%20atmosphere%2C%20ocean%2C%20and%20terrestrial%20hydrosphere%20processes%2C%20stable%20isotope%20ratios%20of%20these%20gases%20%28e.g.%20Xe-136%5C%2FXe-129%29%20are%20seldom%20used%20because%20of%20low%20signal-to-noise%20ratios.%20Here%20we%20present%20the%20first%20results%20from%20a%20new%20method%20of%20dissolved%20gas%20sampling%2C%20extraction%20and%20analysis%20that%20permits%20measurement%20of%20stable%20Ar%2C%20Kr%2C%20and%20Xe%20isotope%20ratios%20at%20or%20below%20similar%20to%205%20per%20meg%20amu%28-1%29%20precision%20%281%20sigma%29%2C%20two%20orders-of-magnitude%20below%20conventional%20Kr%20and%20Xe%20isotopic%20measurements.%20This%20gain%20in%20precision%20was%20achieved%20by%20quantitative%20extraction%20and%20subsequent%20purification%20of%20dissolved%20noble%20gases%20from%202-L%20water%20samples%20via%20helium%20sparging%20and%20viscous%20dual-inlet%20isotope%20ratio%20mass%20spectrometry.%20We%20have%20determined%20the%20solubility%20fractionation%20factors%20%28alpha%28sol%29%29%20for%20stable%20Ar%2C%20Kr%2C%20and%20Xe%20isotope%20ratios%20between%20similar%20to%202%20and%2020%20degrees%20C%20via%20laboratory%20equilibration%20experiments.%20We%20have%20also%20conducted%20temperature-controlled%20air-water%20gas%20exchange%20experiments%20to%20estimate%20the%20kinetic%20fractionation%20factors%20%28alpha%28kin%29%29%20of%20these%20isotope%20ratios.%20We%20find%20that%20both%20alpha%28sol%29%20and%20alpha%28kin%29%2C%20normalized%20by%20isotopic%20mass%20difference%20%28Delta%20m%29%2C%20decrease%20in%20magnitude%20with%20atomic%20number%20but%20are%20proportional%20to%20Delta%20m%20for%20isotope%20ratios%20of%20the%20same%20element.%20With%20the%20new%20ability%20for%20high%20precision%20isotopic%20measurements%2C%20we%20suggest%20that%20dissolved%20Kr%20and%20Xe%20isotope%20ratios%20in%20groundwater%20represent%20a%20promising%2C%20novel%20geochemical%20tool%20with%20important%20applications%20for%20groundwater%20modeling%2C%20water%20resource%20management%2C%20and%20paleoclimate.%20%28C%29%202019%20Elsevier%20B.V.%20All%20rights%20reserved.%22%2C%22date%22%3A%222019%5C%2F05%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.1016%5C%2Fj.epsl.2019.03.008%22%2C%22ISSN%22%3A%220012-821X%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A20Z%22%7D%7D%2C%7B%22key%22%3A%22ASIWQQXN%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Bauska%20et%20al.%22%2C%22parsedDate%22%3A%222018-08%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EBauska%2C%20T.%20K.%2C%20Brook%2C%20E.%20J.%2C%20Marcott%2C%20S.%20A.%2C%20Baggenstos%2C%20D.%2C%20Shackleton%2C%20S.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20%26amp%3B%20Petrenko%2C%20V.%20V.%20%282018%29.%20Controls%20on%20Millennial-Scale%20Atmospheric%20CO2%20Variability%20During%20the%20Last%20Glacial%20Period.%20%3Ci%3EGeophysical%20Research%20Letters%3C%5C%2Fi%3E%2C%20%3Ci%3E45%3C%5C%2Fi%3E%2815%29%2C%207731%26%23x2013%3B7740.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1029%5C%2F2018gl077881%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1029%5C%2F2018gl077881%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Controls%20on%20Millennial-Scale%20Atmospheric%20CO2%20Variability%20During%20the%20Last%20Glacial%20Period%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%20K.%22%2C%22lastName%22%3A%22Bauska%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20J.%22%2C%22lastName%22%3A%22Brook%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%20A.%22%2C%22lastName%22%3A%22Marcott%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22D.%22%2C%22lastName%22%3A%22Baggenstos%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22S.%22%2C%22lastName%22%3A%22Shackleton%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22V.%20V.%22%2C%22lastName%22%3A%22Petrenko%22%7D%5D%2C%22abstractNote%22%3A%22Changes%20in%20atmospheric%20CO2%20on%20millennial-to-centennial%20timescales%20are%20key%20components%20of%20past%20climate%20variability%20during%20the%20last%20glacial%20and%20deglacial%20periods%20%2870-10%20ka%29%2C%20yet%20the%20sources%20and%20mechanisms%20responsible%20for%20the%20CO2%20fluctuations%20remain%20largely%20obscure.%20Here%20we%20report%20the%20C-13%5C%2FC-12%20ratio%20of%20atmospheric%20CO2%20during%20a%20key%20interval%20of%20the%20last%20glacial%20period%20at%20submillennial%20resolution%2C%20with%20coeval%20histories%20of%20atmospheric%20CO2%2C%20CH4%2C%20and%20N2O%20concentrations.%20The%20carbon%20isotope%20data%20suggest%20that%20the%20millennial-scale%20CO2%20variability%20in%20Marine%20Isotope%20Stage%203%20is%20driven%20largely%20by%20changes%20in%20the%20organic%20carbon%20cycle%2C%20most%20likely%20by%20sequestration%20of%20respired%20carbon%20in%20the%20deep%20ocean.%20Centennial-scale%20CO2%20variations%2C%20distinguished%20by%20carbon%20isotope%20signatures%2C%20are%20associated%20with%20both%20abrupt%20hydrological%20change%20in%20the%20tropics%20%28e.g.%2C%20Heinrich%20events%29%20and%20rapid%20increases%20in%20Northern%20Hemisphere%20temperature%20%28Dansgaard-Oeschger%20events%29.%20These%20events%20can%20be%20linked%20to%20modes%20of%20variability%20during%20the%20last%20deglaciation%2C%20thus%20suggesting%20that%20drivers%20of%20millennial%20and%20centennial%20CO2%20variability%20during%20both%20periods%20are%20intimately%20linked%20to%20abrupt%20climate%20variability.%20Plain%20Language%20Summary%20Ice%20cores%20provide%20unique%20records%20of%20variations%20in%20atmospheric%20CO2%20prior%20to%20the%20instrumental%20era.%20While%20it%20is%20clear%20that%20changes%20in%20atmospheric%20CO2%20played%20a%20significant%20role%20in%20driving%20past%20climate%20change%2C%20it%20is%20unclear%20what%20in%20turn%20drove%20changes%20in%20atmospheric%20CO2.%20Here%20we%20investigate%20enigmatic%20changes%20in%20atmospheric%20CO2%20levels%20during%20an%20interval%20of%20the%20last%20glacial%20period%20%28similar%20to%2050%2C000%20to%2035%2C000%20years%20ago%29%20that%20are%20associated%20with%20abrupt%20changes%20in%20polar%20climate.%20To%20determine%20the%20sources%20and%20sinks%20for%20atmospheric%20CO2%2C%20we%20measured%20the%20stable%20isotopes%20of%20carbon%20in%20CO2%20and%20found%20that%20the%20primary%20source%20of%20carbon%20to%20the%20atmosphere%20was%20an%20organic%20carbon%20reservoir.%20Most%20likely%2C%20this%20carbon%20was%20sourced%20from%20a%20deep%20ocean%20reservoir%20that%20waxed%20and%20waned%20following%20changes%20in%20either%20the%20productivity%20of%20the%20surface%20ocean%20or%20stratification%20of%20the%20deep%20ocean.%20We%20also%20found%20that%20atmospheric%20CO2%20can%20change%20on%20the%20centennial%20timescale%20during%20abrupt%20climate%20transitions%20in%20the%20Northern%20Hemisphere.%20This%20observation%20adds%20to%20a%20growing%20body%20of%20evidence%20that%20abrupt%20changes%20in%20atmospheric%20CO2%20are%20an%20important%20component%20of%20past%20carbon%20cycle%20variability.%22%2C%22date%22%3A%22Aug%202018%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.1029%5C%2F2018gl077881%22%2C%22ISSN%22%3A%220094-8276%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A15Z%22%7D%7D%2C%7B%22key%22%3A%22YVYADGW5%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Wagner%20et%20al.%22%2C%22parsedDate%22%3A%222018-08%22%2C%22numChildren%22%3A6%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EWagner%2C%20T.%20J.%20W.%2C%20Dell%2C%20R.%20W.%2C%20Eisenman%2C%20I.%2C%20Keeling%2C%20R.%20F.%2C%20Padman%2C%20L.%2C%20%26amp%3B%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%20%282018%29.%20Wave%20inhibition%20by%20sea%20ice%20enables%20trans-Atlantic%20ice%20rafting%20of%20debris%20during%20Heinrich%20events.%20%3Ci%3EEarth%20and%20Planetary%20Science%20Letters%3C%5C%2Fi%3E%2C%20%3Ci%3E495%3C%5C%2Fi%3E%2C%20157%26%23x2013%3B163.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1016%5C%2Fj.epsl.2018.05.006%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1016%5C%2Fj.epsl.2018.05.006%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22Wave%20inhibition%20by%20sea%20ice%20enables%20trans-Atlantic%20ice%20rafting%20of%20debris%20during%20Heinrich%20events%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22T.%20J.%20W.%22%2C%22lastName%22%3A%22Wagner%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%20W.%22%2C%22lastName%22%3A%22Dell%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22I.%22%2C%22lastName%22%3A%22Eisenman%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%20F.%22%2C%22lastName%22%3A%22Keeling%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22L.%22%2C%22lastName%22%3A%22Padman%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%5D%2C%22abstractNote%22%3A%22The%20last%20glacial%20period%20was%20punctuated%20by%20episodes%20of%20massive%20iceberg%20calving%20from%20the%20Laurentide%20Ice%20Sheet%2C%20called%20Heinrich%20events%2C%20which%20are%20identified%20by%20layers%20of%20ice-rafted%20debris%20%28IRD%29%20in%20ocean%20sediment%20cores%20from%20the%20North%20Atlantic.%20The%20thickness%20of%20these%20IRD%20layers%20declines%20more%20gradually%20with%20distance%20from%20the%20iceberg%20sources%20than%20would%20be%20expected%20based%20on%20present-day%20iceberg%20drift%20and%20decay.%20Here%20we%20model%20icebergs%20as%20passive%20Lagrangian%20particles%20driven%20by%20ocean%20currents%2C%20winds%2C%20and%20sea%20surface%20temperatures.%20The%20icebergs%20are%20released%20in%20a%20comprehensive%20climate%20model%20simulation%20of%20the%20last%20glacial%20maximum%20%28LGM%29%2C%20as%20well%20as%20a%20simulation%20of%20the%20modern%20climate.%20The%20two%20simulated%20climates%20result%20in%20qualitatively%20similar%20distributions%20of%20iceberg%20meltwater%20and%20hence%20debris%2C%20with%20the%20colder%20temperatures%20of%20the%20LGM%20having%20only%20a%20relatively%20small%20effect%20on%20meltwater%20spread.%20In%20both%20scenarios%2C%20meltwater%20flux%20falls%20off%20rapidly%20with%20zonal%20distance%20from%20the%20source%2C%20in%20contrast%20with%20the%20more%20uniform%20spread%20of%20IRD%20in%20sediment%20cores.%20To%20address%20this%20discrepancy%2C%20we%20propose%20a%20physical%20mechanism%20that%20could%20have%20prolonged%20the%20lifetime%20of%20icebergs%20during%20Heinrich%20events.%20The%20mechanism%20involves%20a%20surface%20layer%20of%20cold%20and%20fresh%20meltwater%20formed%20from%2C%20and%20retained%20around%2C%20large%20densely%20packed%20armadas%20of%20icebergs.%20This%20leads%20to%20wintertime%20sea%20ice%20formation%20even%20in%20relatively%20low%20latitudes.%20The%20sea%20ice%20in%20turn%20shields%20the%20icebergs%20from%20wave%20erosion%2C%20which%20is%20the%20main%20source%20of%20iceberg%20ablation.%20We%20find%20that%20sea%20ice%20could%20plausibly%20have%20formed%20around%20the%20icebergs%20during%20four%20months%20each%20winter.%20Allowing%20for%20four%20months%20of%20sea%20ice%20in%20the%20model%20results%20in%20a%20simulated%20IRD%20distribution%20which%20approximately%20agrees%20with%20the%20distribution%20of%20IRD%20in%20sediment%20cores.%20%28C%29%202018%20Elsevier%20B.V.%20All%20rights%20reserved.%22%2C%22date%22%3A%222018%5C%2F08%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.1016%5C%2Fj.epsl.2018.05.006%22%2C%22ISSN%22%3A%220012-821X%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22EU5YC9TT%22%2C%22WBZK3IXM%22%2C%22NSCTF3T8%22%5D%2C%22dateModified%22%3A%222022-09-28T15%3A33%3A34Z%22%7D%7D%2C%7B%22key%22%3A%22RYQLRD7U%22%2C%22library%22%3A%7B%22id%22%3A9129767%7D%2C%22meta%22%3A%7B%22creatorSummary%22%3A%22Baggenstos%20et%20al.%22%2C%22parsedDate%22%3A%222018-07%22%2C%22numChildren%22%3A2%7D%2C%22bib%22%3A%22%3Cdiv%20class%3D%5C%22csl-bib-body%5C%22%20style%3D%5C%22line-height%3A%202%3B%20padding-left%3A%201em%3B%20text-indent%3A-1em%3B%5C%22%3E%5Cn%20%20%3Cdiv%20class%3D%5C%22csl-entry%5C%22%3EBaggenstos%2C%20D.%2C%20%3Cstrong%3ESeveringhaus%3C%5C%2Fstrong%3E%2C%20J.%20P.%2C%20Mulvaney%2C%20R.%2C%20McConnell%2C%20J.%20R.%2C%20Sigl%2C%20M.%2C%20Maselli%2C%20O.%2C%20Petit%2C%20J.%20R.%2C%20Grente%2C%20B.%2C%20%26amp%3B%20Steig%2C%20E.%20J.%20%282018%29.%20A%20Horizontal%20Ice%20Core%20From%20Taylor%20Glacier%2C%20Its%20Implications%20for%20Antarctic%20Climate%20History%2C%20and%20an%20Improved%20Taylor%20Dome%20Ice%20Core%20Time%20Scale.%20%3Ci%3EPaleoceanography%20and%20Paleoclimatology%3C%5C%2Fi%3E%2C%20%3Ci%3E33%3C%5C%2Fi%3E%287%29%2C%20778%26%23x2013%3B794.%20%3Ca%20class%3D%27zp-DOIURL%27%20href%3D%27https%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1029%5C%2F2017pa003297%27%3Ehttps%3A%5C%2F%5C%2Fdoi.org%5C%2F10.1029%5C%2F2017pa003297%3C%5C%2Fa%3E%3C%5C%2Fdiv%3E%5Cn%3C%5C%2Fdiv%3E%22%2C%22data%22%3A%7B%22itemType%22%3A%22journalArticle%22%2C%22title%22%3A%22A%20Horizontal%20Ice%20Core%20From%20Taylor%20Glacier%2C%20Its%20Implications%20for%20Antarctic%20Climate%20History%2C%20and%20an%20Improved%20Taylor%20Dome%20Ice%20Core%20Time%20Scale%22%2C%22creators%22%3A%5B%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22D.%22%2C%22lastName%22%3A%22Baggenstos%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20P.%22%2C%22lastName%22%3A%22Severinghaus%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22R.%22%2C%22lastName%22%3A%22Mulvaney%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20R.%22%2C%22lastName%22%3A%22McConnell%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22M.%22%2C%22lastName%22%3A%22Sigl%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22O.%22%2C%22lastName%22%3A%22Maselli%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22J.%20R.%22%2C%22lastName%22%3A%22Petit%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22B.%22%2C%22lastName%22%3A%22Grente%22%7D%2C%7B%22creatorType%22%3A%22author%22%2C%22firstName%22%3A%22E.%20J.%22%2C%22lastName%22%3A%22Steig%22%7D%5D%2C%22abstractNote%22%3A%22Ice%20core%20records%20from%20Antarctica%20show%20mostly%20synchronous%20temperature%20variations%20during%20the%20last%20deglacial%20transition%2C%20an%20indication%20that%20the%20climate%20of%20the%20entire%20continent%20reacted%20as%20one%20unit%20to%20the%20global%20changes.%20However%2C%20a%20record%20from%20the%20Taylor%20Dome%20ice%20core%20in%20the%20Ross%20Sea%20sector%20of%20East%20Antarctica%20has%20been%20suggested%20to%20show%20a%20rapid%20warming%2C%20similar%20in%20style%20and%20synchronous%20with%20the%20Oldest%20Dryas-Bolling%20warming%20in%20Greenland.%20Since%20publication%20of%20the%20Taylor%20Dome%20record%2C%20a%20number%20of%20lines%20of%20evidence%20have%20suggested%20that%20this%20interpretation%20is%20incorrect%20and%20reflects%20errors%20in%20the%20underlying%20time%20scale.%20The%20issues%20raised%20regarding%20the%20dating%20of%20Taylor%20Dome%20currently%20linger%20unresolved%2C%20and%20the%20original%20time%20scale%20remains%20the%20de%20facto%20chronology.%20We%20present%20new%20water%20isotope%20and%20chemistry%20data%20from%20nearby%20Taylor%20Glacier%20to%20resolve%20the%20confusion%20surrounding%20the%20Taylor%20Dome%20time%20scale.%20We%20find%20that%20the%20Taylor%20Glacier%20record%20is%20incompatible%20with%20the%20original%20interpretation%20of%20the%20Taylor%20Dome%20ice%20core%2C%20showing%20that%20the%20warming%20in%20the%20area%20was%20gradual%20and%20started%20at%20similar%20to%2018%20ka%20BP%20%28before%201950%29%20as%20seen%20in%20other%20East%20Antarctic%20ice%20cores.%20We%20build%20a%20consistent%2C%20up-to-date%20Taylor%20Dome%20chronology%20from%200%20to%2060%20ka%20BP%20by%20combining%20new%20and%20old%20age%20markers%20based%20on%20synchronization%20to%20other%20ice%20core%20records.%20The%20most%20notable%20feature%20of%20the%20new%20TD2015%20time%20scale%20is%20a%20gas%20age-ice%20age%20difference%20of%20up%20to%2012%2C000%20years%20during%20the%20Last%20Glacial%20Maximum%2C%20by%20far%20the%20largest%20ever%20observed.%22%2C%22date%22%3A%22Jul%202018%22%2C%22language%22%3A%22%22%2C%22DOI%22%3A%2210.1029%5C%2F2017pa003297%22%2C%22ISSN%22%3A%222572-4517%22%2C%22url%22%3A%22%22%2C%22collections%22%3A%5B%22WBZK3IXM%22%5D%2C%22dateModified%22%3A%222022-06-21T23%3A19%3A18Z%22%7D%7D%5D%7D
Grimmer, M., Baggenstos, D., Schmitt, J., Krauss, F., Shackleton, S., Severinghaus, J. P., & Fischer, H. (2025). AMOC Modulates Ocean Heat Content During Deglaciations. Geophysical Research Letters, 52(6), e2024GL114415. https://doi.org/10.1029/2024GL114415
Martin, K. C., Buizert, C., Brook, E., Williams, O. L., Edwards, J. S., Riddell‐Young, B., Fudge, T. J., Mederbel, F., Beaudette, R., Severinghaus, J., Oyabu, I., Kawamura, K., Kirk, M., Koldtoft, I., Steffensen, J. P., & Blunier, T. (2024). Greenland Ice Cores Reveal a South‐To‐North Difference in Holocene Thermal Maximum Timings. Geophysical Research Letters, 51(24), e2024GL111405. https://doi.org/10.1029/2024GL111405
Harris Stuart, R., Landais, A., Arnaud, L., Buizert, C., Capron, E., Dumont, M., Libois, Q., Mulvaney, R., Orsi, A., Picard, G., Prié, F., Severinghaus, J., Stenni, B., & Martinerie, P. (2024). On the relationship between δ O 2 ∕N 2 variability and ice sheet surface conditions in Antarctica. The Cryosphere, 18(8), 3741–3763. https://doi.org/10.5194/tc-18-3741-2024
Hmiel, B., Petrenko, V. V., Buizert, C., Smith, A. M., Dyonisius, M. N., Place, P., Yang, B., Hua, Q., Beaudette, R., Severinghaus, J. P., Harth, C., Weiss, R. F., Davidge, L., Diaz, M., Pacicco, M., Menking, J. A., Kalk, M., Faïn, X., Adolph, A., … Murray, L. T. (2024). Characterization of in situ cosmogenic 14 CO production, retention and loss in firn and shallow ice at Summit, Greenland. The Cryosphere, 18(7), 3363–3382. https://doi.org/10.5194/tc-18-3363-2024
Ng, J., Severinghaus, J., Bay, R., & Tosi, D. (2024). Evaluating marine dust records as templates for optical dating of Oldest Ice. Climate of the Past, 20(7), 1437–1449. https://doi.org/10.5194/cp-20-1437-2024
Holliday, Vance. T., Daulton, T. L., Bartlein, P. J., Boslough, M. B., Breslawski, R. P., Fisher, A. E., Jorgeson, I. A., Scott, A. C., Koeberl, C., Marlon, J. R., Severinghaus, J., Petaev, M. I., & Claeys, P. (2024). Rebuttal of Sweatman, Powell, and West’s “Rejection of Holliday et al.’s alleged refutation of the Younger Dryas Impact Hypothesis.” Earth-Science Reviews, 258, 104961. https://doi.org/10.1016/j.earscirev.2024.104961
Patterson, J. D., Aydin, M., Crotwell, A. M., Pétron, G., Severinghaus, J. P., Krummel, P. B., Langenfelds, R. L., Petrenko, V. V., & Saltzman, E. S. (2023). Reconstructing atmospheric H 2 over the past century from bi-polar firn air records. Climate of the Past, 19(12), 2535–2550. https://doi.org/10.5194/cp-19-2535-2023
Epifanio, J. A., Brook, E. J., Buizert, C., Pettit, E. C., Edwards, J. S., Fegyveresi, J. M., Sowers, T. A., Severinghaus, J. P., & Kahle, E. C. (2023). Millennial and orbital-scale variability in a 54 000-year record of total air content from the South Pole ice core. The Cryosphere, 17(11), 4837–4851. https://doi.org/10.5194/tc-17-4837-2023
Venugopal, A. U., Bertler, N. A. N., Severinghaus, J. P., Brook, E. J., Cortese, G., Lee, J. E., Blunier, T., Mayewski, P. A., Kjær, H. A., Carter, L., Weber, M. E., Levy, R. H., Pyne, R. L., & Vandergoes, M. J. (2023). Antarctic evidence for an abrupt northward shift of the Southern Hemisphere westerlies at 32 ka BP. Nature Communications, 14(1), 5432. https://doi.org/10.1038/s41467-023-40951-1
Martin, K. C., Buizert, C., Edwards, J. S., Kalk, M. L., Riddell-Young, B., Brook, E. J., Beaudette, R., Severinghaus, J. P., & Sowers, T. A. (2023). Bipolar impact and phasing of Heinrich-type climate variability. Nature, 617(7959), 100–104. https://doi.org/10.1038/s41586-023-05875-2
Ng, J., Tyne, R., Seltzer, A., Noyes, C., McIntosh, J., & Severinghaus, J. (2023). A new large‐volume equilibration method for high‐precision measurements of dissolved noble gas stable isotopes. Rapid Communications in Mass Spectrometry, 37(7). https://doi.org/10.1002/rcm.9471
Buizert, C., Shackleton, S., Severinghaus, J. P., Roberts, W. H. G., Seltzer, A., Bereiter, B., Kawamura, K., Baggenstos, D., Orsi, A. J., Oyabu, I., Birner, B., Morgan, J. D., Brook, E. J., Etheridge, D. M., Thornton, D., Bertler, N., Pyne, R. L., Mulvaney, R., Mosley-Thompson, E., … Petrenko, V. V. (2023). The new Kr-86 excess ice core proxy for synoptic activity: West Antarctic storminess possibly linked to Intertropical Convergence Zone (ITCZ) movement through the last deglaciation. Climate of the Past, 19(3), 579–606. https://doi.org/10.5194/cp-19-579-2023
Dyonisius, M. N., Petrenko, V. V., Smith, A. M., Hmiel, B., Neff, P. D., Yang, B., Hua, Q., Schmitt, J., Shackleton, S. A., Buizert, C., Place, P. F., Menking, J. A., Beaudette, R., Harth, C., Kalk, M., Roop, H. A., Bereiter, B., Armanetti, C., Vimont, I., … McConnell, J. R. (2023). Using ice core measurements from Taylor Glacier, Antarctica, to calibrate in situ cosmogenic 14 C production rates by muons. The Cryosphere, 17(2), 843–863. https://doi.org/10.5194/tc-17-843-2023
Holliday, V. T., Daulton, T. L., Bartlein, P. J., Boslough, M. B., Breslawski, R. P., Fisher, A. E., Jorgeson, I. A., Scott, A. C., Koeberl, C., Marlon, J. R., Severinghaus, J., Petaev, M. I., & Claeys, P. (2023). Comprehensive refutation of the Younger Dryas Impact Hypothesis (YDIH). Earth-Science Reviews, 247, 104502. https://doi.org/10.1016/j.earscirev.2023.104502
Thompson, L. G., Severinghaus, J. P., Yao, T., Davis, M. E., Mosley-Thompson, E., Beaudon, E., Sierra-Hernández, M. R., & Porter, S. E. (2022). Use of δ 18 O atm in dating a Tibetan ice core record of Holocene/Late Glacial climate. Proceedings of the National Academy of Sciences, 119(45), e2205545119. https://doi.org/10.1073/pnas.2205545119
Dong, X. Y., Kathayat, G., Rasmussen, S. O., Svensson, A., Severinghaus, J. P., Li, H. Y., Sinha, A., Xu, Y., Zhang, H. W., Shi, Z. G., Cai, Y. J., Perez-Mejias, C., Baker, J., Zhao, J. Y., Spotl, C., Columbu, A., Ning, Y. F., Strikis, N. M., Chen, S. T., … Cheng, H. (2022). Coupled atmosphere-ice-ocean dynamics during Heinrich Stadial 2. Nature Communications, 13(1), 14. https://doi.org/10.1038/s41467-022-33583-4
Menking, J. A., Shackleton, S. A., Bauska, T. K., Buffen, A. M., Brook, E. J., Barker, S., Severinghaus, J. P., Dyonisius, M. N., & Petrenko, V. V. (2022). Multiple carbon cycle mechanisms associated with the glaciation of Marine Isotope Stage 4. Nature Communications, 13(1), 5443. https://doi.org/10.1038/s41467-022-33166-3
Morgan, J. D., Buizert, C., Fudge, T. J., Kawamura, K., Severinghaus, J. P., & Trudinger, C. M. (2022). Gas isotope thermometry in the South Pole and Dome Fuji ice cores provides evidence for seasonal rectification of ice core gas records. The Cryosphere, 16(7), 2947–2966. https://doi.org/10.5194/tc-16-2947-2022
Birner, B., Severinghaus, J., Paplawsky, B., & Keeling, R. F. (2022). Increasing atmospheric helium due to fossil fuel exploitation. Nature Geoscience, 15(5), 346-+. https://doi.org/10.1038/s41561-022-00932-3
Yan, Y. Z., Brook, E. J., Kurbatov, A. V., Severinghaus, J. P., & Higgins, J. A. (2021). Ice core evidence for atmospheric oxygen decline since the Mid-Pleistocene transition. Science Advances, 7(51), 11. https://doi.org/10.1126/sciadv.abj9341
Oyabu, I., Kawamura, K., Uchida, T., Fujita, S., Kitamura, K., Hirabayashi, M., Aoki, S., Morimoto, S., Nakazawa, T., Severinghaus, J. P., & Morgan, J. D. (2021). Fractionation of O-2/N-2 and Ar/N-2 in the Antarctic ice sheet during bubble formation and bubble-clathrate hydrate transition from precise gas measurements of the Dome Fuji ice core. Cryosphere, 15(12), 5529–5555. https://doi.org/10.5194/tc-15-5529-2021
Seltzer, A. M., Krantz, J. A., Ng, J., Danskin, W. R., Bekaert, D. V., Barry, P. H., Kimbrough, D. L., Kulongoski, J. T., & Severinghaus, J. P. (2021). The triple argon isotope composition of groundwater on ten-thousand-year timescales. Chemical Geology, 583, 10. https://doi.org/10.1016/j.chemgeo.2021.120458
Shackleton, S., Menking, J. A., Brook, E., Buizert, C., Dyonisius, M. N., Petrenko, V. V., Baggenstos, D., & Severinghaus, J. P. (2021). Evolution of mean ocean temperature in Marine Isotope Stage 4. Climate of the Past, 17(5), 2273–2289. https://doi.org/10.5194/cp-17-2273-2021
Patterson, J. D., Aydin, M., Crotwell, A. M., Petron, G., Severinghaus, J. P., Krummel, P. B., Langenfelds, R. L., & Saltzman, E. S. (2021). H2 in Antarctic firn air: Atmospheric reconstructions and implications for anthropogenic emissions. Proceedings of the National Academy of Sciences of the United States of America, 118(36), 8. https://doi.org/10.1073/pnas.2103335118
Goodge, J. W., Severinghaus, J. P., Johnson, J., Tosi, D., & Bay, R. (2021). Deep ice drilling, bedrock coring and dust logging with the Rapid Access Ice Drill (RAID) at Minna Bluff, Antarctica. Annals of Glaciology, 62(85–86), 324–339. https://doi.org/10.1017/aog.2021.13
He, C. F., Liu, Z. Y., Otto-Bliesner, B. L., Brady, E. C., Zhu, C. Y., Tomas, R., Buizert, C., & Severinghaus, J. P. (2021). Abrupt Heinrich Stadial 1 cooling missing in Greenland oxygen isotopes. Science Advances, 7(25). https://doi.org/10.1126/sciadv.abh1007
Buizert, C., Fudge, T. J., Roberts, W. H. G., Steig, E. J., Sherriff-Tadano, S., Ritz, C., Lefebvre, E., Edwards, J., Kawamura, K., Oyabu, I., Motoyama, H., Kahle, E. C., Jones, T. R., Abe-Ouchi, A., Obase, T., Martin, C., Corr, H., Severinghaus, J. P., Beaudette, R., … Schwander, J. (2021). Antarctic surface temperature and elevation during the Last Glacial Maximum. Science, 372(6546), 1097-+. https://doi.org/10.1126/science.abd2897
Seltzer, A. M., Ng, J., Aeschbach, W., Kipfer, R., Kulongoski, J. T., Severinghaus, J. P., & Stute, M. (2021). Widespread six degrees Celsius cooling on land during the Last Glacial Maximum. Nature, 593(7858), 228-+. https://doi.org/10.1038/s41586-021-03467-6
Birner, B., Paplawsky, W., Severinghaus, J., & Keeling, R. F. (2021). A method for resolving changes in atmospheric He / N-2 as an indicator of fossil fuel extraction and stratospheric circulation. Atmospheric Measurement Techniques, 14(3), 2515–2527. https://doi.org/10.5194/amt-14-2515-2021
Epifanio, J. A., Brook, E. J., Buizert, C., Edwards, J. S., Sowers, T. A., Kahle, E. C., Severinghaus, J. P., Steig, E. J., Winski, D. A., Osterberg, E. C., Fudge, T. J., Aydin, M., Hood, E., Kalk, M., Kreutz, K. J., Ferris, D. G., & Kennedy, J. A. (2020). The SP19 chronology for the South Pole Ice Core - Part 2: gas chronology, Eage, and smoothing of atmospheric records. Climate of the Past, 16(6), 2431–2444. https://doi.org/10.5194/cp-16-2431-2020
Oyabu, I., Kawamura, K., Kitamura, K., Dallmayr, R., Kitamura, A., Sawada, C., Severinghaus, J. P., Beaudette, R., Orsi, A., Sugawara, S., Ishidoya, S., Dahl-Jensen, D., Goto-Azuma, K., Aoki, S., & Nakazawa, T. (2020). New technique for high-precision, simultaneous measurements of CH4, N2O and CO2 concentrations; isotopic and elemental ratios of N-2, O-2 and Ar; and total air content in ice cores by wet extraction. Atmospheric Measurement Techniques, 13(12), 6703–6731. https://doi.org/10.5194/amt-13-6703-2020
Menking, J. A., Brook, E. J., Schilt, A., Shackleton, S., Dyonisius, M., Severinghaus, J. P., & Petrenko, V. V. (2020). Millennial-scale changes in terrestrial and marine nitrous oxide emissions at the onset and termination of Marine Isotope Stage 4. Geophysical Research Letters, 47(22). https://doi.org/10.1029/2020gl089110
Birner, B., Chipperfield, M. P., Morgan, E. J., Stephens, B. B., Linz, M., Feng, W. H., Wilson, C., Bent, J. D., Wofsy, S. C., Severinghaus, J., & Keeling, R. F. (2020). Gravitational separation of Ar/N-2 and age of air in the lowermost stratosphere in airborne observations and a chemical transport model. Atmospheric Chemistry and Physics, 20(21), 12391–12408. https://doi.org/10.5194/acp-20-12391-2020
Cheng, H., Zhang, H. W., Spotl, C., Baker, J., Sinha, A., Li, H. Y., Bartolome, M., Moreno, A., Kathayat, G., Zhao, J. Y., Dong, X. Y., Li, Y. W., Ning, Y. F., Jia, X., Zong, B. Y., Brahim, Y. A., Perez-Mejias, C., Cai, Y. J., Novello, V. F., … Edwards, R. L. (2020). Timing and structure of the Younger Dryas event and its underlying climate dynamics. Proceedings of the National Academy of Sciences of the United States of America, 117(38), 23408–23417. https://doi.org/10.1073/pnas.2007869117
Lee, J. E., Brook, E. J., Bertler, N. A. N., Buizert, C., Baisden, T., Blunier, T., Ciobanu, V. G., Conway, H., Dahl-Jensen, D., Fudge, T. J., Hindmarsh, R., Keller, E. D., Parrenin, F., Severinghaus, J. P., Vallelonga, P., Waddington, E. D., & Winstrup, M. (2020). An 83,000-year-old ice core from Roosevelt Island, Ross Sea, Antarctica. Climate of the Past, 16(5), 1691–1713. https://doi.org/10.5194/cp-16-1691-2020
Patterson, J. D., Aydin, M., Crotwell, A. M., Petron, G., Severinghaus, J. P., & Saltzman, E. S. (2020). Atmospheric history of H-2 over the past century reconstructed from South Pole firn air. Geophysical Research Letters, 47(14). https://doi.org/10.1029/2020gl087787
Dyonisius, M. N., Petrenko, V. V., Smith, A. M., Hua, Q., Yang, B., Schmitt, J., Beck, J., Seth, B., Bock, M., Hmiel, B., Vimont, I., Menking, J. A., Shackleton, S. A., Baggenstos, D., Bauska, T. K., Rhodes, R. H., Sperlich, P., Beaudette, R., Harth, C., … Weiss, R. F. (2020). Old carbon reservoirs were not important in the deglacial methane budget. Science, 367(6480), 907-+. https://doi.org/10.1126/science.aax0504
Hmiel, B., Petrenko, V. V., Dyonisius, M. N., Buizert, C., Smith, A. M., Place, P. F., Harth, C., Beaudette, R., Hua, Q., Yang, B., Vimont, I., Michel, S. E., Severinghaus, J. P., Etheridge, D., Bromley, T., Schmitt, J., Fa?n, X., Weiss, R. F., & Dlugokencky, E. (2020). Preindustrial (CH4)-C-14 indicates greater anthropogenic fossil CH4 emissions. Nature, 578(7795), 409-+. https://doi.org/10.1038/s41586-020-1991-8
Shackleton, S., Baggenstos, D., Menking, J. A., Dyonisius, M. N., Bereiter, B., Bauska, T. K., Rhodes, R. H., Brook, E. J., Petrenko, V. V., McConnell, J. R., Kellerhals, T., Haberli, M., Schmitt, J., Fischer, H., & Severinghaus, J. P. (2020). Global ocean heat content in the Last Interglacial. Nature Geoscience, 13(1). https://doi.org/10.1038/s41561-019-0498-0
Seltzer, A. M., Ng, J., Danskin, W. R., Kulongoski, J. T., Gannon, R. S., Stute, M., & Severinghaus, J. P. (2019). Deglacial water-table decline in Southern California recorded by noble gas isotopes. Nature Communications, 10. https://doi.org/10.1038/s41467-019-13693-2
Yan, Y. Z., Bender, M. L., Brook, E. J., Clifford, H. M., Kemeny, P. C., Kurbatov, A. V., Mackay, S., Mayewski, P. A., Ng, J., Severinghaus, J. P., & Higgins, J. A. (2019). Two-million-year-old snapshots of atmospheric gases from Antarctic ice. Nature, 574(7780), 663-+. https://doi.org/10.1038/s41586-019-1692-3
Winski, D. A., Fudge, T. J., Ferris, D. G., Osterberg, E. C., Fegyveresi, J. M., Cole-Dai, J., Thundercloud, Z., Cox, T. S., Kreutz, K. J., Ortman, N., Buizert, C., Epifanio, J., Brook, E. J., Beaudette, R., Severinghaus, J., Sowers, T., Steig, E. J., Kahle, E. C., Jones, T. R., … McConnell, J. R. (2019). The SP19 chronology for the South Pole Ice Core - Part 1: volcanic matching and annual layer counting. Climate of the Past, 15(5), 1793–1808. https://doi.org/10.5194/cp-15-1793-2019
Mühle, J., Trudinger, C. M., Western, L. M., Rigby, M., Vollmer, M. K., Park, S., Manning, A. J., Say, D., Ganesan, A., Steele, L. P., Ivy, D. J., Arnold, T., Li, S., Stohl, A., Harth, C. M., Salameh, P. K., McCulloch, A., O’Doherty, S., Park, M. K., … Weiss, R. F. (2019). Perfluorocyclobutane (PFC-318, c-C4F8) in the global atmosphere. Atmospheric Chemistry and Physics, 19(15), 10335–10359. https://doi.org/10.5194/acp-19-10335-2019
Menking, J. A., Brook, E. J., Shackleton, S. A., Severinghaus, J. P., Dyonisius, M. N., Petrenko, V., McConnell, J. R., Rhodes, R. H., Bauska, T. K., Baggenstos, D., Marcott, S., & Barker, S. (2019). Spatial pattern of accumulation at Taylor Dome during Marine Isotope Stage 4: stratigraphic constraints from Taylor Glacier. Climate of the Past, 15(4), 1537–1556. https://doi.org/10.5194/cp-15-1537-2019
Seltzer, A. M., Pavia, F. J., Ng, J., & Severinghaus, J. P. (2019). Heavy noble gas isotopes as new constraints on the ventilation of the deep ocean. Geophysical Research Letters, 46(15), 8926–8932. https://doi.org/10.1029/2019gl084089
Baggenstos, D., Haberli, M., Schmitt, J., Shackleton, S. A., Birner, B., Severinghaus, J. P., Kellerhals, T., & Fischer, H. (2019). Earth’s radiative imbalance from the Last Glacial Maximum to the present. Proceedings of the National Academy of Sciences of the United States of America, 116(30), 14881–14886. https://doi.org/10.1073/pnas.1905447116
Seltzer, A. M., Ng, J., & Severinghaus, J. P. (2019). Precise determination of Ar, Kr and Xe isotopic fractionation due to diffusion and dissolution in fresh water. Earth and Planetary Science Letters, 514, 156–165. https://doi.org/10.1016/j.epsl.2019.03.008
Bauska, T. K., Brook, E. J., Marcott, S. A., Baggenstos, D., Shackleton, S., Severinghaus, J. P., & Petrenko, V. V. (2018). Controls on Millennial-Scale Atmospheric CO2 Variability During the Last Glacial Period. Geophysical Research Letters, 45(15), 7731–7740. https://doi.org/10.1029/2018gl077881
Wagner, T. J. W., Dell, R. W., Eisenman, I., Keeling, R. F., Padman, L., & Severinghaus, J. P. (2018). Wave inhibition by sea ice enables trans-Atlantic ice rafting of debris during Heinrich events. Earth and Planetary Science Letters, 495, 157–163. https://doi.org/10.1016/j.epsl.2018.05.006
Baggenstos, D., Severinghaus, J. P., Mulvaney, R., McConnell, J. R., Sigl, M., Maselli, O., Petit, J. R., Grente, B., & Steig, E. J. (2018). A Horizontal Ice Core From Taylor Glacier, Its Implications for Antarctic Climate History, and an Improved Taylor Dome Ice Core Time Scale. Paleoceanography and Paleoclimatology, 33(7), 778–794. https://doi.org/10.1029/2017pa003297