Preliminary study on assimilation of significant wave heights from T/P altimeter

Abstract

结合经验的台风风场模型和NCEP再分析资料构造了南海台风风场,并以此作为一个第三代海浪模式的输入模拟了1999年约克(York)台风经过南海时所产生的台风浪场.模拟结果显示,尽管文中构造的南海台风风场比较接近真实的风场,但模拟出的台风浪场相对于TOPEX/Poseidon高度计的观测波高仍有一定差异,因此进而采用了一种简单的最优插值同化方法,开展了波高资料的初步同化试验.试验结果显示,资料同化显著地改进了海浪模式的(后)预报精度,而这种改进在涌浪区更加显著,同化有效维持时间大约是43h. Combining the NCEP re-analysis wind data with an empirical typhoon wind model,the wind fields are formed and compared with the TOPEX/Poseidon altimetric wind speeds,there is generally consistency between them.The wind fields are used to drive a third-generation wind wave model to simulate the wave fields in the South China Sea during the period of Typhoon York in 1999.The significant wave heights from the wave model are underestimated while compared with the TOPEX/Poseidon altimetric data.Then,a simple optimal interpolation assimilation technology is employed in the wave model,the result shows that the performance of the wave model is improved and its impact of assimilation is obvious especially in the swell part. The lasting time of the assimilation is about (43 h.)