不同卫星微波遥感资料同化对台风路径模拟的影响

Effects of Assimilating Microwave Remote Sensing Data of Different Satellite on the Simulation of Typhoon Track

本文以2015年13号超强台风"苏迪罗"为个例,利用WRF模式及其3DVar同化系统对NOAA15、NOAA18和NOAA19的AMSU-A微波遥感资料分别同化及组合同化,探究同化不同卫星的同一种微波遥感资料对于台风路径模拟效果的影响。结果表明:同化不同卫星的同一种微波遥感资料对于台风路径模拟具有不同的调整,本文中NOAA15的同化效果最好,其次是NOAA18,最后是NOAA19;同时同化NOAA15、NOAA18和NOAA19的AMSU-A资料并没有取得最好的同化效果,而组合NOAA15和NOAA18则取得了最好的同化效果,即不是同化的卫星数量越多,同化效果越好;同化试验3个时刻的增量场表明同化不同卫星的同一种微波遥感资料对物理场具有不同的调整,这与其对台风模拟路径的调整有着较好的对应,相对于温度场、海平面气压场、位势高度场和风场的增量结构与模拟台风路径的调整更为密切。

In this study, AMSU-A（Advanced Microwave Sounding Unit-A） microwave remote sensing data of NOAA15, NOAA18, and NOAA19 are assimilated respectively and combinedly to simulate the super typhoon ＂Soudelor＂（Number 13, 2015） using the WRF model and its 3 DVar assimilation systems. The objective of the present study is to investigate the effects of assimilating the same type of microwave remote sensing data from different satellites on the simulation of typhoon track. The results demonstrate that assimilation of the same type of microwave remote sensing data from different satellites leads to different effects on the simulation of typhoon track. In this paper, the assimilation effect of NOAA15 is the best, followed by that of NOAA18, and the effect of NOAA19 data assimilation is the worst. Assimilating the AMSU-A data of NOAA15, NOAA18, and NOAA19 simultaneously didn＇t yield the best assimilation effect, whereas assimilating the AMSU-A data of combined NOAA15 and NOAA18 had the best assimilation effects. The above results indicate that assimilating observation data of more satellites doesn＇t necessarily lead to better assimilation effect. The increment fields at three different times in the assimilation experiments demonstrate that assimilating the same type of microwave remote sensing data from different satellites lead to different adjustments on physical fields, which correspond well to the adjustments on the simulation of typhoon track. Compared to the incremental structures of temperature, sea level pressure, geopotential height, and winds are more closely linked with the adjustment of the simulation of typhoon track.