THE AMUNDSEN SEA AND THE ANTARCTIC ICE SHEET
THE AMUNDSEN SEA AND THE ANTARCTIC ICE SHEET
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DOI：
10.5670/oceanog.2012.90
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发表时间：
2012-09-01
期刊：
影响因子：
2.8
通讯作者：
Guerrero, Raul
中科院分区：
文献类型：
--
作者：
Jacobs, Stan;Jenkins, Adrian;Guerrero, Raul
几十年前，随着大气变暖，南极冰盖预计会增大，向极地的湿气输送增加，导致全年保持在冰点以下的地区降雪量增加。对气候变化敏感性的担忧主要集中在气温和冰川动态上。南大洋的角色被降级为冰山运输、冰架下融化和冻结的混合体，并受到海冰产生产生的寒冷陆架水域的缓冲，以及其他强迫作用导致的海平面缓慢上升。当时，偏远的阿蒙森海缺乏观测，那里恶劣的冰况困扰了探险家 200 多年。 1994 年开始对其海洋结构和环流进行测绘，揭示了“温暖”的环极深水可以进入其大陆架。海底的冰川冲刷槽为海水提供了管道，使靠近其深接地线的区域冰架更快地融化。一致的卫星数据显示，冰架正在变薄，进而导致冰川流动加速和接地冰流失到海洋中。重复的测量和建模表明海洋变化可能会影响以海洋为基础的西南极冰盖的稳定性。
A few decades ago, Antarctic ice sheets were expected to grow as the atmosphere warmed and increasing poleward moisture transport added snowfall to regions that would remain below freezing year-round. Concerns about their sensitivity to climate change were centered on air temperature and on glacially paced ice dynamics. Southern Ocean roles were relegated to iceberg transport, a mix of melting and freezing under ice shelves buffered by the frigid shelf waters generated by sea ice production, and slow sea level rise by other forcing. At that time, observations were lacking in the remote Amundsen Sea, where difficult ice conditions have vexed explorers for more than 200 years. Mapping of its ocean structure and circulation began in 1994, revealing that "warm" Circumpolar Deep Water has access to its continental shelf. Glacially scoured troughs in the seafloor provide conduits for that seawater to melt regional ice shelves far more rapidly near their deep grounding lines. Coincident satellite data showed the ice shelves were thinning, in turn leading to accelerated glacier flow and loss of grounded ice to the sea. Repeated measurements and modeling suggest ocean changes that could impact the stability of the marine-based West Antarctic Ice Sheet.