Roles of vertical turbulent mixing in the ocean response to Typhoon Rex (1998)
Roles of vertical turbulent mixing in the ocean response to Typhoon Rex (1998)
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DOI：
10.1007/s10872-009-0034-8
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发表时间：
2009-04
影响因子：
2.3
通讯作者：
A. Wada;H. Niino;H. Nakano
中科院分区：
文献类型：
--
作者：
A. Wada;H. Niino;H. Nakano
利用MRI.COM模式，以1998年台风雷克斯为例，研究了垂直湍流混合在海面冷却中的作用随热带气旋移动速度的变化。COM很好地再现了TRMM/TMI三天平均海表温度（SST）场沿着雷克斯的路径。在雷克斯快速移动阶段，MRI.COM模拟的SSC是由轨道右侧的剪切诱导VTM引起的。另一方面，在缓慢移动阶段，埃克曼抽水区大部分重叠的VTM区后面的雷克斯的中心。在反流阶段，由上升流输送的冷水更有效地夹带到混合层的VTM近1近惯性期后，雷克斯的通道。然后，我们修改了Deardorff（1983）的卷吸公式，并将其纳入到一个板状混合层海洋模式（SOM）中，以适应MRI. COM的模拟结果。主要的修改如下：（1）考虑由表面波破碎引起的湍流动能（TKE）产生;（2）增加用于估计耗散的系数，以平衡由于湍流输送引起的TKE产生;和（3）改变临界Richardson数的初始猜测。这些修改导致SST模拟SOM的改进。结果表明，修正对模拟SST的影响比初始混合层深度和日变化短波辐射与日平均短波辐射之间的差异的影响更显著。
How the role of vertical turbulent mixing (VTM) in sea surface cooling (SSC) varies with the moving speed of a tropical cyclone was examined for Typhoon Rex (1998) by using the Meteorological Research Institute Community Ocean Model (MRI.COM). The MRI.COM well reproduced TRMM/TMI three-day mean sea surface temperature (SST) fields along Rex’s track. During the fast-moving phase of Rex, SSC simulated by the MRI.COM was caused by shear-induced VTM on the right side of the track. During the slowly-moving phase, on the other hand, the Ekman-pumping area mostly overlapped the VTM area right behind Rex’s center. During the recurvature phase, cool water transported by the upwelling was more efficiently entrained into a mixed layer by the VTM for nearly a 1 near-inertial period after the passage of Rex. We then modified the entrainment formulation of Deardorff (1983), which was incorporated into a slab mixed-layer ocean model (SOM) so as to fit to the results simulated by the MRI.COM. The principal modifications are as follows: (1) consideration of turbulent kinetic energy (TKE) production caused by surface wave breaking; (2) increase in the coefficient for estimating dissipation to balance with TKE production due to turbulent transport; and (3) changing the initial guess for the critical Richardson number. These modifications led to an improvement of SST simulations by the SOM. The impact of the modifications on simulated SSTs turned out to be more significant than the impacts of initial mixed-layer depth and the difference between diurnally-varying and daily mean short-wave radiation.