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Palaeoclimate evidence of vulnerable permafrost during times of low sea ice 期刊论文
NATURE, 2020, 577 (7789) : 221-+
作者:  Vaks, A.;  Mason, A. J.;  Breitenbach, S. F. M.;  Kononov, A. M.;  Osinzev, A. V.;  Rosensaft, M.;  Borshevsky, A.;  Gutareva, O. S.;  Henderson, G. M.
收藏  |  浏览/下载:33/0  |  提交时间:2020/05/13

Climate change in the Arctic is occurring rapidly, and projections suggest the complete loss of summer sea ice by the middle of this century(1). The sensitivity of permanently frozen ground (permafrost) in the Northern Hemisphere to warming is less clear, and its long-term trends are harder to monitor than those of sea ice. Here we use palaeoclimate data to show that Siberian permafrost is robust to warming when Arctic sea ice is present, but vulnerable when it is absent. Uranium-lead chronology of carbonate deposits (speleothems) in a Siberian cave located at the southern edge of continuous permafrost reveals periods in which the overlying ground was not permanently frozen. The speleothem record starts 1.5 million years ago (Ma), a time when greater equator-to-pole heat transport led to a warmer Northern Hemisphere(2). The growth of the speleothems indicates that permafrost at the cave site was absent at that time, becoming more frequent from about 1.35 Ma, as the Northern Hemisphere cooled, and permanent after about 0.4 Ma. This history mirrors that of year-round sea ice in the Arctic Ocean, which was largely absent before about 0.4 Ma (ref.(3)), but continuously present since that date. The robustness of permafrost when sea ice is present, as well as the increased permafrost vulnerability when sea ice is absent, can be explained by changes in both heat and moisture transport. Reduced sea ice may contribute to warming of Arctic air(4-6), which can lead to warming far inland(7). Open Arctic waters also increase the source of moisture and increase autumn snowfall over Siberia, insulating the ground from low winter temperatures(8-10). These processes explain the relationship between an ice-free Arctic and permafrost thawing before 0.4 Ma. If these processes continue during modern climate change, future loss of summer Arctic sea ice will accelerate the thawing of Siberian permafrost.


  
Towards normal Siberian winter temperatures? 期刊论文
INTERNATIONAL JOURNAL OF CLIMATOLOGY, 2019, 39 (11) : 4567-4574
作者:  Koenigk, Torben;  Fuentes-Franco, Ramon
收藏  |  浏览/下载:10/0  |  提交时间:2019/11/27
Arctic sea ice reduction  climate variability  North Atlantic Oscillation  Pacific Decadal Oscillation  Siberian cooling  winter temperature trends  
Fram Strait sea ice export affected by thinning: comparing high-resolution simulations and observations 期刊论文
CLIMATE DYNAMICS, 2019, 53: 3257-3270
作者:  Zamani, Behnam;  Krumpen, Thomas;  Smedsrud, Lars H.;  Gerdes, Ruediger
收藏  |  浏览/下载:25/0  |  提交时间:2019/11/27
Ocean-sea ice model  Fram Strait  Sea ice area export  Sea ice volume export  Sea ice export trends  High-resolution model  Arctic sea ice mass balance  
Nonuniform Contribution of Internal Variability to Recent Arctic Sea Ice Loss 期刊论文
JOURNAL OF CLIMATE, 2019, 32 (13) : 4039-4053
作者:  England, Mark;  Jahn, Alexandra;  Polvani, Lorenzo
收藏  |  浏览/下载:14/0  |  提交时间:2019/11/27
Arctic  Sea ice  Ensembles  Interannual variability  Multidecadal variability  Trends  
Revisiting the Linkages between the Variability of Atmospheric Circulations and Arctic Melt-Season Sea Ice Cover at Multiple Time Scales 期刊论文
JOURNAL OF CLIMATE, 2019, 32 (5) : 1461-1482
作者:  Yu, Lejiang;  Zhong, Shiyuan;  Zhou, Mingyu;  Lenschow, Donald H.;  Sun, Bo
收藏  |  浏览/下载:21/0  |  提交时间:2019/04/09
Arctic  Sea ice  Arctic Oscillation  Atmosphere-ocean interaction  Climate variability  Trends  
A 40-y record reveals gradual Antarctic sea ice increases followed by decreases at rates far exceeding the rates seen in the Arctic 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2019, 116 (29) : 14414-14423
作者:  Parkinson, Claire L.
收藏  |  浏览/下载:18/0  |  提交时间:2019/11/27
sea ice  climate change  satellite Earth observations  climate trends  Antarctic sea ice  
Stratospheric Ozone Depletion: An Unlikely Driver of the Regional Trends in Antarctic Sea Ice in Austral Fall in the Late Twentieth Century 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2017, 44 (21)
作者:  Landrum, Laura L.;  Holland, Marika M.;  Raphael, Marilyn N.;  Polvani, Lorenzo M.
收藏  |  浏览/下载:18/0  |  提交时间:2019/04/09
Antarctic sea ice trends  stratrospheric ozone depletion  Amundsen Sea Low  
Toward an ice-free Barents Sea 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2017, 44 (16)
作者:  Onarheim, Ingrid H.;  Arthun, Marius
收藏  |  浏览/下载:10/0  |  提交时间:2019/04/09
Barents Sea  sea ice trends  observations  coupled climate models  Arctic  internal variability