ATOVS亮温资料同化在台风数值模拟中的应用

An application of ATOVS radiance in data assimilation of typhoon

利用三维变分同化技术,通过将ATOVS(Advanced TIROS-N Operational Vertical Sounder)(包括AMSUA和AMSUB微波辐射探测器及高分辨率红外辐射探测器HIRS)亮度温度资料直接同化进中尺度数值预报模式WRF中,以提高模式对台风路径的模拟精度。针对两个台风个例鲇鱼(2010)和纳沙(2011)进行了同化试验,结果表明:1)同化卫星亮温资料能够改善台风初始场结构(大气流场、温度场和水汽场),进而提高对台风路径的模拟精度;2)不同资料的同化效果不一样,同化AMSUA资料对台风的路径模拟有较明显的改善效果,而同化HIRS3资料和AMSUB资料则无明显改善效果;3)卫星资料同化对于改变环境引导气流有较大作用,可以通过影响副高的强弱和位置改变环境气流场,从而影响台风的路径。

In this study, the Advanced Television and Infrared Observation Satellite Operational Vertical Sounder（ATOVS） radiance （including AMSUA, AMSUB and HIRS） was assimilated into the Weather Research and Forecasting（WRF） model to improve track simulation of Typhoon Megi （2010） and Typhoon Nesat （2011） using thethree-dimensional variational （3DVAR） approach. The results from a series of assimilation experiments are as follows.1） The assimilation of the radiance data can improve the accuracy of typhoon track simulation through adjusting theinitial fields of typhoon structure including the atmospheric circulation, temperature and moisture. 2） Different satelliteradiance data have different effects on improving typhoon track simulation. The improvement by AMSUA data isobviously greater than that by AMSUB data or HIRS3 data. 3） The assimilation of satellite radiance data cansignificantly influence the environmental steering flow through changing the strength and location of the subtropicalhigh, leading to the improvement of typhoon track simulation.