Rapid sea-level rise along the Antarctic margins in response to increased glacial discharge
Rapid sea-level rise along the Antarctic margins in response to increased glacial discharge
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DOI：
10.1038/ngeo2230
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发表时间：
2014-10-01
影响因子：
18.3
通讯作者：
Webb, David J.
中科院分区：
文献类型：
--
作者：
Rye, Craig D.;Garabato, Alberto C. Naveira;Webb, David J.
南极陆架海是一个在气候和生态方面都很重要的区域，目前正从南极冰盖及其边缘冰架（主要是在南极半岛和阿蒙森海周边）的融化中接收越来越多的淡水。相应地，该区域的表层海洋盐度在过去几十年中已经下降（3 - 9）。在此，我们利用卫星对海面高度的测量（针对无海冰覆盖的月份）以及一个全球海洋环流模型来评估淡水输入对区域海平面的影响。我们发现，从1992年到2011年，南极海岸沿线的海平面上升比南纬50度以南的南大洋区域平均值至少高出2 ± 0.8毫米/年。基于模型模拟，我们得出结论，这种海平面上升几乎完全与热比容调整有关，而非局部海洋质量的变化，其中上层海洋有盐热比容上升，深层有热比容贡献。我们估计，需要430 ± 230亿吨/年的过量淡水输入来解释观测到的海平面上升。我们得出结论，在过去的二十年中，南极冰盖加速消融对邻近的副极地海域产生了显著且广泛的影响。
The Antarctic shelf seas are a climatically and ecologically important region, and are at present receiving increasing amounts of freshwater from the melting of the Antarctic Ice Sheet and its fringing ice shelves(1,2), primarily around the Antarctic Peninsula and the Amudsen Sea. In response, the surface ocean salinity in this region has declined in past decades(3-9). Here, we assess the effects of the freshwater input on regional sea level using satellite measurements of sea surface height (for months with no sea-ice cover) and a global ocean circulation model. We find that from 1992 to 2011, sea-level rise along the Antarctic coast is at least 2 +/- 0.8 mm yr(-1) greater than the regional mean for the Southern Ocean south of 50 degrees S. On the basis of the model simulations, we conclude that this sea-level rise is almost entirely related to steric adjustment, rather than changes in local ocean mass, with a halosteric rise in the upper ocean and thermosteric contributions at depth. We estimate that an excess freshwater input of 430 +/- 230 Gt yr(-1) is required to explain the observed sea-level rise. We conclude that accelerating discharge from the Antarctic Ice Sheet has had a pronounced and widespread impact on the adjacent subpolar seas over the past two decades.