A numerical study of Stokes drift and thermal effects on the oceanic mixed layer
A numerical study of Stokes drift and thermal effects on the oceanic mixed layer
复制标题
海洋混合层斯托克斯漂移和热效应的数值研究
DOI：
10.1007/s13131-019-1448-9
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发表时间：
2020-05
影响因子：
1.4
通讯作者：
Zou Zhongshui
中科院分区：
文献类型：
--
作者：
Li Xuewei;Zhao Dongliang;Zou Zhongshui
利用Mellor-Yamada湍流闭合方案，研究了Stokes漂移和热力效应对夏季海面温度（SST）偏高、混合层深度（MLD）偏浅时上层海洋偏差的影响。通过普林斯顿海洋模式，在理想强迫和真实的观测情况下，对上层海洋热结构进行了实验检验。结果表明，无论是在夏季还是冬季，斯托克斯漂移都能增强湍流动能，加深MLD。这一影响将改善夏季的模拟结果，但它会导致更深的MLD在冬季相比，观测数据。结果表明，结合斯托克斯漂移和冷表层及暖层对上层混合层的热力作用，可以较好地模拟MLD。在夏季短波辐射高、风速弱的情况下，从太阳吸收的热量被阻挡在暖层中，无法向下传递。结果表明，夏季的热力效应对斯托克斯漂移导致MLD加深的动力效应几乎没有影响。而当冬季层结较弱时，热力效应会通过增强层结强度来抵消斯托克斯漂流的动力效应，抑制混合影响。因此，为了正确模拟夏季和冬季的上层海洋热结构，应同时考虑动力和热力效应。
This study explores the influence of Stokes drift and the thermal effects on the upper ocean bias which occurs in the summer with overestimated sea surface temperature (SST) and shallower mixed layer depth (MLD) using Mellor-Yamada turbulence closure scheme. The upper ocean thermal structures through Princeton ocean model are examined by experiments in the cases of idealized forcing and real observational situation. The results suggest that Stokes drift can generally enhance turbulence kinetic energy and deepen MLD either in summer or in winter. This effect will improve the simulation results in summer, but it will lead to much deeper MLD in winter compared to observational data. It is found that MLD can be correctly simulated by combining Stokes drift and the thermal effects of the cool skin layer and diurnal warm layer on the upper mixing layer. In the case of high shortwave radiation and weak wind speed, which usually occurs in summer, the heat absorbed from sun is blocked in the warm layer and prevented from being transferred downwards. As a result, the thermal effects in summer nearly has no influence on dynamic effect of Stokes drift that leads to deepening MLD. However, when the stratification is weak in winter, the thermal effects will counteract the dynamic effect of Stokes drift through enhancing the strength of stratification and suppress mixing impact. Therefore, the dynamic and thermal effects should be considered simultaneously in order to correctly simulate upper ocean thermal structures in both summer and winter.
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影响因子：
5.2
作者：
Chia-Ying Tu;B. Tsuang
通讯作者：
Chia-Ying Tu;B. Tsuang
影响因子：
5.2
作者：
B. Ward;M. Donelan
通讯作者：
B. Ward;M. Donelan
影响因子：
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作者：
P. Martin
通讯作者：
P. Martin
影响因子：
3.5
作者：
Nirnimesh Kumar;F. Feddersen
通讯作者：
Nirnimesh Kumar;F. Feddersen
影响因子：
3.7
作者：
P. Sullivan;James C. McWilliams;W. Melville
通讯作者：
P. Sullivan;James C. McWilliams;W. Melville