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国际研究揭示冰川消融对生物多样性和生态系统功能的影响 快报文章
气候变化快报,2025年第10期
作者:  董利苹 杜海霞
Microsoft Word(15Kb)  |  收藏  |  浏览/下载:402/0  |  提交时间:2025/05/20
Deglaciation  Biodiversity  Ecosystem Function  
气候变化导致第三极洪水风险剧增 快报文章
气候变化快报,2021年第10期
作者:  董利苹
Microsoft Word(15Kb)  |  收藏  |  浏览/下载:490/0  |  提交时间:2021/05/20
Glacial Lake Outburst Floods  Risk  Deglaciation  
Ice retreat in Wilkes Basin of East Antarctica during a warm interglacial 期刊论文
NATURE, 2020, 583 (7817) : 554-+
作者:  T. Blackburn;  G. H. Edwards;  S. Tulaczyk;  M. Scudder;  G. Piccione;  B. Hallet;  N. McLean;  J. C. Zachos;  B. Cheney;  J. T. Babbe
收藏  |  浏览/下载:61/0  |  提交时间:2020/08/09

Uranium isotopes in subglacial precipitates from the Wilkes Basin of the East Antarctic Ice Sheet reveal ice retreat during a warm Pleistocene interglacial period about 400,000 years ago.


Efforts to improve sea level forecasting on a warming planet have focused on determining the temperature, sea level and extent of polar ice sheets during Earth'  s past interglacial warm periods(1-3). About 400,000 years ago, during the interglacial period known as Marine Isotopic Stage 11 (MIS11), the global temperature was 1 to 2 degrees Celsius greater(2)and sea level was 6 to 13 metres higher(1,3). Sea level estimates in excess of about 10 metres, however, have been discounted because these require a contribution from the East Antarctic Ice Sheet(3), which has been argued to have remained stable for millions of years before and includes MIS11(4,5). Here we show how the evolution of(234)U enrichment within the subglacial waters of East Antarctica recorded the ice sheet'  s response to MIS11 warming. Within the Wilkes Basin, subglacial chemical precipitates of opal and calcite record accumulation of(234)U (the product of rock-water contact within an isolated subglacial reservoir) up to 20 times higher than that found in marine waters. The timescales of(234)U enrichment place the inception of this reservoir at MIS11. Informed by the(234)U cycling observed in the Laurentide Ice Sheet, where(234)U accumulated during periods of ice stability(6)and was flushed to global oceans in response to deglaciation(7), we interpret our East Antarctic dataset to represent ice loss within the Wilkes Basin at MIS11. The(234)U accumulation within the Wilkes Basin is also observed in the McMurdo Dry Valleys brines(8-10), indicating(11)that the brine originated beneath the adjacent East Antarctic Ice Sheet. The marine origin of brine salts(10)and bacteria(12)implies that MIS11 ice loss was coupled with marine flooding. Collectively, these data indicate that during one of the warmest Pleistocene interglacials, the ice sheet margin at the Wilkes Basin retreated to near the precipitate location, about 700 kilometres inland from the current position of the ice margin, which-assuming current ice volumes-would have contributed about 3 to 4 metres(13)to global sea levels.


  
Millennial-scale hydroclimate control of tropical soil carbon storage 期刊论文
NATURE, 2020, 581 (7806) : 63-+
作者:  Lam, Tommy Tsan-Yuk;  Jia, Na;  Zhang, Ya-Wei;  Shum, Marcus Ho-Hin;  Jiang, Jia-Fu;  Zhu, Hua-Chen;  Tong, Yi-Gang;  Shi, Yong-Xia;  Ni, Xue-Bing;  Liao, Yun-Shi;  Li, Wen-Juan;  Jiang, Bao-Gui;  Wei, Wei;  Yuan, Ting-Ting;  Zheng, Kui;  Cui, Xiao-Ming;  Li, Jie;  Pei, Guang-Qian
收藏  |  浏览/下载:61/0  |  提交时间:2020/05/13

Over the past 18,000 years, the residence time and amount of soil carbon stored in the Ganges-Brahmaputra basin have been controlled by the intensity of Indian Summer Monsoon rainfall, with greater carbon destabilization during wetter, warmer conditions.


The storage of organic carbon in the terrestrial biosphere directly affects atmospheric concentrations of carbon dioxide over a wide range of timescales. Within the terrestrial biosphere, the magnitude of carbon storage can vary in response to environmental perturbations such as changing temperature or hydroclimate(1), potentially generating feedback on the atmospheric inventory of carbon dioxide. Although temperature controls the storage of soil organic carbon at mid and high latitudes(2,3), hydroclimate may be the dominant driver of soil carbon persistence in the tropics(4,5)  however, the sensitivity of tropical soil carbon turnover to large-scale hydroclimate variability remains poorly understood. Here we show that changes in Indian Summer Monsoon rainfall have controlled the residence time of soil carbon in the Ganges-Brahmaputra basin over the past 18,000 years. Comparison of radiocarbon ages of bulk organic carbon and terrestrial higher-plant biomarkers with co-located palaeohydrological records(6) reveals a negative relationship between monsoon rainfall and soil organic carbon stocks on a millennial timescale. Across the deglaciation period, a depletion of basin-wide soil carbon stocks was triggered by increasing rainfall and associated enhanced soil respiration rates. Our results suggest that future hydroclimate changes in tropical regions are likely to accelerate soil carbon destabilization, further increasing atmospheric carbon dioxide concentrations.


  
Wind-Driven Evolution of the North Pacific Subpolar Gyre Over the Last Deglaciation 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2020, 47 (6)
作者:  Gray, William R.;  Wills, Robert C. J.;  Rae, James W. B.;  Burke, Andrea;  Ivanovic, Ruza F.;  Roberts, William H. G.;  Ferreira, David;  Valdes, Paul J.
收藏  |  浏览/下载:22/0  |  提交时间:2020/07/02
North Pacific  deglaciation  gyre circulation  westerlies  oxygen isotopes  climate models  
Oceanic forcing of penultimate deglacial and last interglacial sea-level rise 期刊论文
NATURE, 2020, 577 (7792) : 660-+
作者:  Rizal, Yan;  Westaway, Kira E.;  Zaim, Yahdi;  van den Bergh, Gerrit D.;  Bettis, E. Arthur, III;  Morwood, Michael J.;  Huffman, O. Frank;  Grun, Rainer;  Joannes-Boyau, Renaud;  Bailey, Richard M.;  Sidarto;  Westaway, Michael C.;  Kurniawan, Iwan;  Moore, Mark W.;  Storey, Michael;  Aziz, Fachroel;  Suminto;  Zhao, Jian-xin;  Aswan;  Sipola, Maija E.;  Larick, Roy;  Zonneveld, John-Paul;  Scott, Robert;  Putt, Shelby;  Ciochon, Russell L.
收藏  |  浏览/下载:41/0  |  提交时间:2020/05/13

Sea-level histories during the two most recent deglacial-interglacial intervals show substantial differences(1-3) despite both periods undergoing similar changes in global mean temperature(4,5) and forcing from greenhouse gases(6). Although the last interglaciation (LIG) experienced stronger boreal summer insolation forcing than the present interglaciation(7), understanding why LIG global mean sea level may have been six to nine metres higher than today has proven particularly challenging(2). Extensive areas of polar ice sheets were grounded below sea level during both glacial and interglacial periods, with grounding lines and fringing ice shelves extending onto continental shelves(8). This suggests that oceanic forcing by subsurface warming may also have contributed to ice-sheet loss(9-12) analogous to ongoing changes in the Antarctic(13,14) and Greenland(15) ice sheets. Such forcing would have been especially effective during glacial periods, when the Atlantic Meridional Overturning Circulation (AMOC) experienced large variations on millennial timescales(16), with a reduction of the AMOC causing subsurface warming throughout much of the Atlantic basin(9,12,17). Here we show that greater subsurface warming induced by the longer period of reduced AMOC during the penultimate deglaciation can explain the more-rapid sea-level rise compared with the last deglaciation. This greater forcing also contributed to excess loss from the Greenland and Antarctic ice sheets during the LIG, causing global mean sea level to rise at least four metres above modern levels. When accounting for the combined influences of penultimate and LIG deglaciation on glacial isostatic adjustment, this excess loss of polar ice during the LIG can explain much of the relative sea level recorded by fossil coral reefs and speleothems at intermediate- and far-field sites.


  
Leveraging the Rapid Retreat of the Amundsen Gulf Ice Stream 13,000 Years Ago to Reveal Insight Into North American Deglaciation 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2019, 46 (21) : 12101-12107
作者:  Pico, T.;  Robel, A.;  Powell, E.;  Mix, A. C.;  Mitrovica, J. X.
收藏  |  浏览/下载:11/0  |  提交时间:2020/02/17
Glacial isostatic adjustment  Marine ice sheet instability  Deglaciation  Ice stream  Laurentide Ice Sheet  
Abrupt Bolling-Allerod Warming Simulated under Gradual Forcing of the Last Deglaciation 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2019
作者:  Obase, Takashi;  Abe-Ouchi, Ayako
收藏  |  浏览/下载:23/0  |  提交时间:2019/11/27
deglaciation  AMOC  meltwater  Bolling-Allerod  bipolar seesaw  
Arctic shrub colonization lagged peak postglacial warmth: Molecular evidence in lake sediment from Arctic Canada 期刊论文
GLOBAL CHANGE BIOLOGY, 2019
作者:  Crump, Sarah E.;  Miller, Gifford H.;  Power, Matthew;  Sepulveda, Julio;  Dildar, Nadia;  Coghlan, Megan;  Bunce, Michael
收藏  |  浏览/下载:16/0  |  提交时间:2019/11/27
ancient DNA  Arctic shrubification  deglaciation  dispersal  paleoclimate  paleothermometry  paleovegetation  
Permafrost-carbon mobilization in Beringia caused by deglacial meltwater runoff, sea-level rise and warming 期刊论文
ENVIRONMENTAL RESEARCH LETTERS, 2019, 14 (8)
作者:  Meyer, Vera D.;  Hefter, Jens;  Koehler, Peter;  Tiedemann, Ralf;  Gersonde, Rainer;  Wacker, Lukas;  Mollenhauer, Gesine
收藏  |  浏览/下载:19/0  |  提交时间:2019/11/27
deglaciation  permafrost decomposition  Beringia  Bering Sea  biomarker  atmospheric CO2  Northwest Pacific