TMI降水结构的反演算法和最佳分辨率选取个例试验

Precipitation Structure and Best Resolution for the Precipitation Retrieval of Tropical Cyclone ETAU(T0310) with TRMM/TMI

利用热带降雨测量卫星(TRMM)的微波成像仪(TMI)和星载测雨雷达(PR)资料,选取了2003年出现在西北太平洋亚洲季风区的热带气旋ETAU(T0310),采用间接对数组合方案建立了多频道线性回归算式,对4种不同分辨率(0.1°、0.2°、0.25°、0.5°)进行了TMI反演降水试验。结果表明,间接对数组合法能够较好地表征降水区的范围和强度分布,且反演结果稳定,是由微波亮温资料反演洋面降水的一种较为理想方法。采用0.2°和0.25°分辨率反演降水效果相对较好,具有实际应用价值,能对降水的宏观特征做出一定的指示。本文结果对于利用卫星微波遥感资料反演降水的研究具有一定参考价值。

Using the microwave brightness temperature data from TRMM/TMI and the precipitation rate from TRMM/PR for tropical cyclone ETAU which appeared in the North-west Pacific and Asian monsoon area during 2003, a precipitation retrieval algorithm was constructed with total channel indirect logarithmic composite scheme, four different resolutions in retrieval experiments had been tested separately with microwave brightness temperature data. The results show that using total channel indirect logarithmic composite scheme is significantly better than that using only highfrequency channel data for retrieval effect and the scheme is also more stable. It suggests that the low-frequency microwave information is useful for precipitation retrieval, and the best retrieval resolution are 0.2° and 0.25°. The results of this paper may be worthy for the operational precipitation retrieval with microwave remote sensing data from the meteorological satellite of China.