Tidally Forced Lee Waves Drive Turbulent Mixing Along the Arctic Ocean Margins
Tidally Forced Lee Waves Drive Turbulent Mixing Along the Arctic Ocean Margins
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DOI：
10.1029/2020gl088083
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发表时间：
2020-08-28
影响因子：
5.2
通讯作者：
Kolas, Eivind
中科院分区：
文献类型：
--
作者：
Fer, Ilker;Koenig, Zoe;Kolas, Eivind
在北冰洋，有限的测量表明，在大气强迫的表面混合层之下，最强烈的混合发生在潮流强劲的地方。然而，从潮汐到湍流的能量转换机制以及潮汐驱动混合对北冰洋状态的总体贡献尚不清楚。我们提供了来自斯瓦尔巴群岛北部大陆架的测量结果，显示了10-50米的突然等深垂直位移和与类似于0.15米秒（-1）的跨等深日潮流相关的强烈耗散。在最大下坡流期间，正压潮的能量在斜压背风波中积累，并在松弛水域周围释放。在6小时的湍流事件中，存在高频内波，整个300 m深度的水柱变成湍流，耗散率增加了100倍，湍流热通量平均为15 W m(-2)，而背景速率为1 W m（-2）。
In the Arctic Ocean, limited measurements indicate that the strongest mixing below the atmospherically forced surface mixed layer occurs where tidal currents are strong. However, mechanisms of energy conversion from tides to turbulence and the overall contribution of tidally driven mixing to Arctic Ocean state are poorly understood. We present measurements from the shelf north of Svalbard that show abrupt isopycnal vertical displacements of 10-50 m and intense dissipation associated with cross-isobath diurnal tidal currents of similar to 0.15 m s(-1). Energy from the barotropic tide accumulated in a trapped baroclinic lee wave during maximum downslope flow and was released around slack water. During a 6-hr turbulent event, high-frequency internal waves were present, the full 300-m depth water column became turbulent, dissipation rates increased by a factor of 100, and turbulent heat flux averaged 15 W m(-2)compared with the background rate of 1 W m(-2).