首先利用考虑波浪破碎效应的Mellor-Yamada2. 5阶湍流闭合方案, 探讨了海表温度(SST)对波能因子a和Charnock数b的敏感性问题。然后采用变分数据同化途径, 基于Papa海洋天气站(OWSPapaStation)的上层温度观测数据, 对该参数化方案中的波能因子a和Charnock数b两个参数进行了最优估计。最优估计的结果表明, 当a约为167、b约为4. 1×105时, 价值函数达到最小值。利用上述参数的最优估计进行海温的数值模拟, 可以较好地反映出海表温度的日变化和月变化过程, 模拟的上混合层的温度和深度也与观测较为一致。最后利用以上参数的最优估计结果对湍动能方程进行诊断计算, 研究了波浪破碎对海洋上层湍能量收支的影响。
Sensitivity of sea surface temperature (SST) to wave energy factor a and Charnock parameter b is discussed using Mellor-Yamada 2.5 turbulence closure model in which wave breaking is considered. The upper-ocean temperature data in summer from OWS Station Papa is assimilated to estimate a and b via a variational approach optimally. It shows that the cost function reaches minimum when a =167 and b =4.1×105. Both monthly and daily SSTs at OWS Station Papa can be successfully reconstructed with the optimal a and b , and the simulated temperature and depth of surface mixed layer are also consistent with the observation. The equation of turbulent kinetic energy is diagnosed utilizing the optimal parameters, from which the effect of wave breaking on the turbulent energy budget is revealed.
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