Intensification of Near‐Surface Currents and Shear in the Eastern Arctic Ocean
Intensification of Near‐Surface Currents and Shear in the Eastern Arctic Ocean
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DOI：
10.1029/2020gl089469
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发表时间：
2020-08
影响因子：
5.2
通讯作者：
I. Polyakov;T. Rippeth;I. Fer;T. Baumann;E. Carmack;V. Ivanov;M. Janout;L. Padman;A. Pnyushkov;R. Rember
中科院分区：
文献类型：
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作者：
I. Polyakov;T. Rippeth;I. Fer;T. Baumann;E. Carmack;V. Ivanov;M. Janout;L. Padman;A. Pnyushkov;R. Rember
欧亚海盆东部海洋上部50米处15年（2004-2018年）的系泊观测记录显示，流速和垂直切变增加，与2004-2018年风、冰和海洋上部之间的耦合增加有关，特别是在夏季。在50米以上的流速和切变的大幅增加主要是由半日带中的电流放大2倍，其中包括潮汐和风强迫的近惯性振荡。首次观察到上层洋流和剪切力的增强与层结的减弱相一致。这种耦合将大西洋水的热量与海冰联系起来，其结果是减少了区域海冰的体积。这些结果指出了一种新的正反馈机制，其中海冰范围的减少促进了更有力的惯性振荡和相关的上层海洋切变，从而增强了大西洋水的通风。
A 15‐year (2004–2018) record of mooring observations from the upper 50 m of the ocean in the eastern Eurasian Basin reveals increased current speeds and vertical shear, associated with an increasing coupling between wind, ice, and the upper ocean over 2004–2018, particularly in summer. Substantial increases in current speeds and shears in the upper 50 m are dominated by a two times amplification of currents in the semidiurnal band, which includes tides and wind‐forced near‐inertial oscillations. For the first time the strengthened upper ocean currents and shear are observed to coincide with weakening stratification. This coupling links the Atlantic Water heat to the sea ice, a consequence of which would be reducing regional sea ice volume. These results point to a new positive feedback mechanism in which reduced sea ice extent facilitates more energetic inertial oscillations and associated upper‐ocean shear, thus leading to enhanced ventilation of the Atlantic Water.