Wind-driven mixing at intermediate depths in an ice-free Arctic Ocean
Wind-driven mixing at intermediate depths in an ice-free Arctic Ocean
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DOI：
10.1002/2016gl070454
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发表时间：
2016-09-28
影响因子：
5.2
通讯作者：
Bacon, Sheldon
中科院分区：
文献类型：
--
作者：
Lincoln, Ben J.;Rippeth, Tom P.;Bacon, Sheldon
最近季节性的北冰洋海冰退缩是极地气候变化的一个主要指标。北冰洋一般是平静的，其内部盆地的特点是在中间深度的低水平的湍流混合。相反，在海冰覆盖减少的情况下，有证据表明，由于从大气到海洋的动量转移增加，存在高能内波。2012年夏季异常无冰和暴风雨期间在加拿大盆地进行的新测量显示，先前观察到的与无冰条件相关的内波能量增强。然而，在远离显著地形的中间深度处，混合没有增强。这意味着，与预期的增加风引起的混合减少北极海冰覆盖，在加拿大海盆中部的分层继续抑制湍流混合在中间深度和有效地隔离大西洋和太平洋的大型热库从海面。
Recent seasonal Arctic Ocean sea ice retreat is a major indicator of polar climate change. The Arctic Ocean is generally quiescent with the interior basins characterized by low levels of turbulent mixing at intermediate depths. In contrast, under conditions of reduced sea ice cover, there is evidence of energetic internal waves that have been attributed to increased momentum transfer from the atmosphere to the ocean. New measurements made in the Canada Basin during the unusually ice-free and stormy summer of 2012 show previously observed enhancement of internal wave energy associated with ice-free conditions. However, there is no enhancement of mixing at intermediate depths away from significant topography. This implies that contrary to expectations of increased wind-induced mixing under declining Arctic sea ice cover, the stratification in the central Canada Basin continues to suppress turbulent mixing at intermediate depths and to effectively isolate the large Atlantic and Pacific heat reservoirs from the sea surface.