Sea Ice-Ocean Feedbacks in the Antarctic Shelf Seas
Sea Ice-Ocean Feedbacks in the Antarctic Shelf Seas
复制标题
南极陆架海域的海冰-海洋反馈
DOI：
10.1175/jpo-d-18-0229.1
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发表时间：
2019
影响因子：
3.5
通讯作者：
Frew R
中科院分区：
文献类型：
--
作者：
Frew R
观测到的南极海冰变化鲜为人知，部分原因是由于其与大气和海洋相互作用的复杂性。摘要建立了一种高度简化的海冰-海洋耦合混合层模型，研究了南极大陆架海洋两个不同区域（阿蒙森海为暖陆架水域，威德尔海为冷盐水陆架水域）中海冰-海洋反馈对海冰和海洋混合层演化的重要性。在模拟研究中，我们否认了对地表气温扰动的反馈响应，这表明威德尔海混合层和冰盖的反馈的重要性小于对地表大气条件的敏感性。在阿蒙森海，表面空气温度扰动对海冰的影响与温暖的深水夹带进入混合层的变化相反。净影响取决于由表面扰动驱动的海冰增长变化和由基底驱动的融化变化之间的相对平衡。阿蒙森海暖水夹带的变化对冰体积的影响比表面能量收支的扰动大得多。这在阿蒙森海产生了净负冰反照率反馈，逆转了这种典型的正反馈机制的迹象。
Observed changes in Antarctic sea ice are poorly understood, in part due to the complexity of its interactions with the atmosphere and ocean. A highly simplified, coupled sea ice–ocean mixed layer model has been developed to investigate the importance of sea ice–ocean feedbacks on the evolution of sea ice and the ocean mixed layer in two contrasting regions of the Antarctic continental shelf ocean: the Amundsen Sea, which has warm shelf waters, and the Weddell Sea, which has cold and saline shelf waters. Modeling studies where we deny the feedback response to surface air temperature perturbations show the importance of feedbacks on the mixed layer and ice cover in the Weddell Sea to be smaller than the sensitivity to surface atmospheric conditions. In the Amundsen Sea the effect of surface air temperature perturbations on the sea ice are opposed by changes in the entrainment of warm deep waters into the mixed layer. The net impact depends on the relative balance between changes in sea ice growth driven by surface perturbations and basal-driven melting. The changes in the entrainment of warm water in the Amundsen Sea were found to have a much larger impact on the ice volume than perturbations in the surface energy budget. This creates a net negative ice albedo feedback in the Amundsen Sea, reversing the sign of this typically positive feedback mechanism.