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Continuity of Ice Sheet Mass Loss in Greenland and Antarctica From the GRACE and GRACE Follow-On Missions 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2020, 47 (8)
作者:  Velicogna, Isabella;  Mohajerani, Yara;  Geruo, A.;  Landerer, Felix;  Mouginot, Jeremie;  Noel, Brice;  Rignot, Eric;  Sutterley, Tyler;  van den Broeke, Michiel;  Wessem, Melchior;  Wiese, David
收藏  |  浏览/下载:9/0  |  提交时间:2020/07/02
Antarctica  Greenland  GRACE  mass balance  climate change  glaciology  
Temperate rainforests near the South Pole during peak Cretaceous warmth 期刊论文
NATURE, 2020, 580 (7801) : 81-+
作者:  Johann P. Klages;  Ulrich Salzmann;  Torsten Bickert;  Claus-Dieter Hillenbrand;  Karsten Gohl;  Gerhard Kuhn;  Steven M. Bohaty;  ;  rgen Titschack;  Juliane Mü;  ller;  Thomas Frederichs;  Thorsten Bauersachs;  Werner Ehrmann;  Tina van de Flierdt;  Patric Simõ;  es Pereira;  Robert D. Larter;  Gerrit Lohmann;  Igor Niezgodzki;  Gabriele Uenzelmann-Neben;  Maximilian Zundel;  Cornelia Spiegel;  Chris Mark;  David Chew;  Jane E. Francis;  Gernot Nehrke;  Florian Schwarz;  James A. Smith;  Tim Freudenthal;  Oliver Esper;  Heiko Pä;  like;  Thomas A. Ronge;  Ricarda Dziadek
收藏  |  浏览/下载:12/0  |  提交时间:2020/05/13

The mid-Cretaceous period was one of the warmest intervals of the past 140 million years(1-5), driven by atmospheric carbon dioxide levels of around 1,000 parts per million by volume(6). In the near absence of proximal geological records from south of the Antarctic Circle, it is disputed whether polar ice could exist under such environmental conditions. Here we use a sedimentary sequence recovered from the West Antarctic shelf-the southernmost Cretaceous record reported so far-and show that a temperate lowland rainforest environment existed at a palaeolatitude of about 82 degrees S during the Turonian-Santonian age (92 to 83 million years ago). This record contains an intact 3-metre-long network of in situ fossil roots embedded in a mudstone matrix containing diverse pollen and spores. A climate model simulation shows that the reconstructed temperate climate at this high latitude requires a combination of both atmospheric carbon dioxide concentrations of 1,120-1,680 parts per million by volume and a vegetated land surface without major Antarctic glaciation, highlighting the important cooling effect exerted by ice albedo under high levels of atmospheric carbon dioxide.


  
Englacial Architecture and Age-Depth Constraints Across the West Antarctic Ice Sheet 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2020, 47 (6)
作者:  Ashmore, David W.;  Bingham, Robert G.;  Ross, Neil;  Siegert, Martin;  Jordan, Tom A.;  Mair, Douglas W. F.
收藏  |  浏览/下载:5/0  |  提交时间:2020/07/02
Ice penetrating radar  Englacial stratigraphy  West Antarctica  Radio echo sounding  Holocene  AntArchitecture  
Ice front blocking of ocean heat transport to an Antarctic ice shelf 期刊论文
NATURE, 2020, 578 (7796) : 568-+
作者:  Alexandrov, Ludmil B.;  Kim, Jaegil;  Haradhvala, Nicholas J.;  Huang, Mi Ni;  Ng, Alvin Wei Tian;  Wu, Yang;  Boot, Arnoud;  Covington, Kyle R.;  Gordenin, Dmitry A.;  Bergstrom, Erik N.;  Islam, S. M. Ashiqul;  Lopez-Bigas, Nuria;  Klimczak, Leszek J.;  McPherson, John R.;  Morganella, Sandro;  Sabarinathan, Radhakrishnan;  Wheeler, David A.;  Mustonen, Ville;  Getz, Gad;  Rozen, Steven G.;  Stratton, Michael R.
收藏  |  浏览/下载:12/0  |  提交时间:2020/05/13

The front of the Getz Ice Shelf in West Antarctica creates an abrupt topographic step that deflects ocean currents, suppressing 70% of the heat delivery to the ice sheet.


Mass loss from the Antarctic Ice Sheet to the ocean has increased in recent decades, largely because the thinning of its floating ice shelves has allowed the outflow of grounded ice to accelerate(1,2). Enhanced basal melting of the ice shelves is thought to be the ultimate driver of change(2,3), motivating a recent focus on the processes that control ocean heat transport onto and across the seabed of the Antarctic continental shelf towards the ice(4-6). However, the shoreward heat flux typically far exceeds that required to match observed melt rates(2,7,8), suggesting that other critical controls exist. Here we show that the depth-independent (barotropic) component of the heat flow towards an ice shelf is blocked by the marked step shape of the ice front, and that only the depth-varying (baroclinic) component, which is typically much smaller, can enter the sub-ice cavity. Our results arise from direct observations of the Getz Ice Shelf system and laboratory experiments on a rotating platform. A similar blocking of the barotropic component may occur in other areas with comparable ice-bathymetry configurations, which may explain why changes in the density structure of the water column have been found to be a better indicator of basal melt rate variability than the heat transported onto the continental shelf(9). Representing the step topography of the ice front accurately in models is thus important for simulating ocean heat fluxes and induced melt rates.


  
Paleogene Marine and Terrestrial Development of the West Antarctic Rift System 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2020, 47 (3)
作者:  Coenen, J. J.;  Scherer, R. P.;  Baudoin, P.;  Warny, S.;  Castaneda, I. S.;  Askin, R.
收藏  |  浏览/下载:0/0  |  提交时间:2020/07/02
Deep glacial troughs and stabilizing ridges unveiled beneath the margins of the Antarctic ice sheet 期刊论文
NATURE GEOSCIENCE, 2020, 13 (2) : 132-+
作者:  Morlighem, Mathieu;  Rignot, Eric;  Binder, Tobias;  Blankenship, Donald;  Drews, Reinhard;  Eagles, Graeme;  Eisen, Olaf;  Ferraccioli, Fausto;  Forsberg, Rene;  Fretwell, Peter;  Goel, Vikram;  Greenbaum, Jamin S.;  Gudmundsson, Hilmar;  Guo, Jingxue;  Helm, Veit;  Hofstede, Coen;  Howat, Ian;  Humbert, Angelika;  Jokat, Wilfried;  Karlsson, Nanna B.;  Lee, Won Sang;  Matsuoka, Kenichi;  Millan, Romain;  Mouginot, Jeremie;  Paden, John;  Pattyn, Frank;  Roberts, Jason;  Rosier, Sebastian;  Ruppel, Antonia;  Seroussi, Helene;  Smith, Emma C.;  Steinhage, Daniel;  Sun, Bo;  van den Broeke, Michiel R.;  van Ommen, Tas D.;  van Wessem, Melchior;  Young, Duncan A.
收藏  |  浏览/下载:9/0  |  提交时间:2020/07/02
The local Last Glacial Maximum in McMurdo Sound, Antarctica: Implications for ice-sheet behavior in the Ross Sea Embayment 期刊论文
GEOLOGICAL SOCIETY OF AMERICA BULLETIN, 2020, 132 (1-2) : 31-47
作者:  Christ, Andrew J.;  Bierman, Paul R.
收藏  |  浏览/下载:6/0  |  提交时间:2020/07/02
The Impact of the Extreme 2015-2016 El Nino on the Mass Balance of the Antarctic Ice Sheet 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2019, 46 (23) : 13862-13871
作者:  Bodart, J. A.;  Bingham, R. J.
收藏  |  浏览/下载:4/0  |  提交时间:2020/02/17
Antarctica  El Nino  mass balance  GRACE  precipitation  
Significant Spatial Variability in Radar-Derived West Antarctic Accumulation Linked to Surface Winds and Topography 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2019, 46 (22) : 13126-13134
作者:  Dattler, Marissa E.;  Lenaerts, Jan T. M.;  Medley, Brooke
收藏  |  浏览/下载:9/0  |  提交时间:2020/02/17
surface mass balance  snow accumulation  snow erosion  airborne radar  Antarctic Ice Sheet  near-surface winds  
West Antarctic surface melt triggered by atmospheric rivers 期刊论文
NATURE GEOSCIENCE, 2019, 12 (11) : 911-+
作者:  Wille, Jonathan D.;  Favier, Vincent;  Dufour, Ambroise;  Gorodetskaya, Irina V.;  Turner, John;  Agosta, Cecile;  Codron, Francis
收藏  |  浏览/下载:6/0  |  提交时间:2020/02/16