Stokes drift-induced and direct wind energy inputs into the Ekman layer within the Antarctic Circumpolar Current
Stokes drift-induced and direct wind energy inputs into the Ekman layer within the Antarctic Circumpolar Current
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DOI：
10.1029/2007jc004579
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发表时间：
2008-10
影响因子：
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通讯作者：
K. Wu;B. Liu
中科院分区：
文献类型：
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作者：
K. Wu;B. Liu
[1]将Coriolis-Stokes强迫引入经典Ekman模式，对Ekman层的能量进行了理论分析，结果表明，输入Ekman层的风能有两个分量：风应力对表层Ekman流所作的功和Coriolis-Stokes强迫对混合层水体所作的功。在垂直扩散系数为常数的假设下，推导了直接风能输入和斯托克斯漂移引起的风能输入的解析表达式。通过比较输入到Ekman层的风能，包括和不包括波浪引起的Stokes漂移效应，评估表面波的相对重要性。利用欧洲中期天气预报中心40年再分析风应力和面波资料，估算了南极绕极流（ACC）内Ekman层的总风能输入量为833 GW，其中直接风能输入量为650 GW（78%），Stokes漂移引起的风能输入量为183 GW（22%）。由于波浪效应，输入到ACC中的总机械能与输入到经典Ekman层中的机械能相比增加了约4%（30 GW）。直接风和斯托克斯漂移引起的能源输入到ACC的长期变化也进行了研究。
[1] Theoretical analysis of energetics of the Ekman layer by incorporating the CoriolisStokes forcing into the classical Ekman model shows that the wind energy input to the Ekman layer has two components: the work done by the wind stress on the surface Ekman current and that done by the Coriolis-Stokes forcing on the whole body of water in the mixed layer. Under the assumption of constant vertical diffusivity, analytical forms of the direct wind energy input and the Stokes drift–induced energy input are derived. Assessments of relative importance of surface waves are made by comparing the wind energy input into the Ekman layer with and without wave-induced Stokes drift effects included. Using the European Centre for Medium-Range Weather Forecasts 40-year reanalysis wind stress and surface wave data sets, the total rate of wind energy input into the Ekman layer within the Antarctic Circumpolar Current (ACC) is estimated to be 833 GW, in which the direct wind energy input is 650 GW (78%), and the Stokes drift– induced energy input is 183 GW (22%). The total mechanical energy input into the ACC due to wave effects is increased by approximately 4% (30 GW) compared to that into the classical Ekman layer. Long-term variability of direct wind and Stokes drift–induced energy inputs to the ACC is also examined.