热带测雨卫星TMI探测结果对非降水云液态水路径的反演方案研究  

RETRIEVAL OF LIQUID WATER PATH IN NONPRECIPITATING CLOUDS USING TMI MEASUREMENTS

作　　者：王雨[1] 傅云飞[1] 刘国胜[2] 

机构地区：[1]中国科学技术大学地球与空间科学学院,合肥230026 [2]美国佛罗里达州立大学

出　　处：《气象学报》2006年第4期443-452,共10页Acta Meteorologica Sinica

基　　金：国家重点基础研究专项经费(2004CB418304);中国科学院知识创新工程重要方向项目基金(ZKCX2-SW-210);国家自然科学基金(40175015;40375018);国家自然科学基金海外杰出青年基金(40428006)

摘　　要：根据TRMMTMI的探测特点,结合微波辐射传输模式,研究了针对副热带地区非降水云液态水路径的TMI反演方案,并对反演方案进行了间接检验。首先,利用微波辐射传输模式进行模拟研究,分析了在副热带地区,相应TMI各通道的微波亮温对非降水云液态水路径的响应特点,结果表明37.0GHz和85.5GHz的水平极化通道探测结果对非降水云液态水路径的响应更为敏感;随后,利用模式分析了TMI各单一通道反演的非降水云液态水路径与理论值的差异,并在此基础上给出了利用37.0GHz和85.5GHz的水平极化通道亮温联合反演非降水云液态水路径的方案;最后,利用TMI的探测结果,采用该反演方案对无云区、非降水云区以及台风降水云区进行了反演计算。结果表明,无云区的液态水路径在-1—1g/m2之间,且平均值为10-5量级;非降水云的液态水路径变化范围在0—500g/m2之间,且其水平分布与TRMM的可见光通道0.64μm探测的云分布一致;在台风降水云个例中,随着台风的成熟,高液态水路径的面积比初始阶段增多,且当地表降水率小于5mm/h时,云中液态水路径随地表降水率的增大而逐渐增大。The relationship between microwave brightness temperature （TB） and liquid water path （PLw） in the nonprecipitating cloud and a corresponding retrieval algorithm are studied by using the satellite microwave measurements from the TRMM Microwave Imager （TMI）, together with a radiative transfer model for microwave radiances calculations. Radiative transfer modeling shows that the sensitivities of the TBs at 37.0 GHz and 85.5 GHz horizontal polarization channels to PLW in the non-precipitating cloud are both higher. Then, the differences between PLW retrieved from single channel measurements and theoretical values are analyzed by using the model. Based on above analysis results, a joint retrieval algorithm for PLW of non-precipitating cloud is developed by using the TB measurements of TMI 37.0 GHz and 85.5 GHz horizontal polarization channels. At last, the algorithm is indirectly validated through typical retrieval cases. The retrieval results show that PLW ranged from - 1 to 1 g/m^2 for clear sky, and its mean value is in the order of 10 - 5; PLW in the non-precipitating cloud ranged from 0 to 500 g/m^2, and its horizontal distribution is consistent with that of the cloud detected by the 0. 64 μm visible channel of TRMM; and in the typhoon precipitation case, the area of high PLW increased from the initial stage to the mature stage, and when the precipitation rate is lower than 5 mm/h, the retrieved PLW in typhoon cloud increased with increase in precipitation rate.

关 键 词：TMI 微波反演 非降水云 液态水路径 

分 类 号：P631.443[天文地球—地质矿产勘探]