基于热带测雨卫星探测的东亚降水云结构特征的研究

利用2000—2013年5—10月浙江省70个常规站逐小时降水观测资料来检验同期TRMM卫星3B42RT降水产品，尤其针对台风降水进行了评估。对比分析得出，2000—2013年5—10月3B42RT资料与台站观测资料在3 h、6 h、12 h和24 h 4个时间尺度上降水总量接近，两组数据呈显著正相关，相关系数随时间尺度的增大而加强，相关系数大值区位于浙江西部地区；无论是5—10月还是台风降水期间，3B42RT测雨资料的日变化特征与台站观测资料均较为一致，3B42RT能够准确抓到峰值出现的时间；台风期间3B42RT数据表征的全省降水普遍偏低，但与台站观测数据的相关性明显好于5—10月全时段，且相关系数大值区位于浙江东部沿海地区，台风前后时刻的3B42RT逐3 h降水量差值序列与台站观测降水量差值序列呈显著正相关，两组资料表征的降水量变化随时间的演变趋势较为一致。另外，选取2004年0414号台风“云娜”进行相关分析和基于目标诊断技术检验，发现3B42RT资料对降水的结构预报和实况相似度较高。

Differences between east and west pacific rainfall systems

Hourly precipitation observation data from 70 meteorological stations are used to evaluate the satellite retrieval products of Tropical Rainfall Measuring Mission (TRMM) 3B42RT during May to October from 2000 to 2013 in Zhejiang province. It has been specially assessed for rainfall of typhoons. The results show that the satellite precipitation data is similar to ground rain gauge data in revealing the precipitation amounts for four time-scales, i.e., 3 h, 6 h, 12 h and 24 h. The TRMM 3B42RT data are significantly correlated with rain gauge data. The correlation coefficients increase with the increasing timescale, and the larger values locate in western Zhejiang. In both the periods from May to October and during typhoon, diurnal variations of rainfall characterized by TRMM 3B42RT show a good agreement with rain gauge data. The 3B42RT can also reflect correctly the peak of rainfall. The 3B42RT products underestimate the typhoon rainfall in Zhejiang Province. But the correlation between TRMM 3B42RT and rain gauge data during typhoon is much better than that during the whole period from May to October, and the larger correlation coefficients locate in eastern coastal areas of Zhejiang during typhoon. The 3h accumulated precipitation difference sequence computed by 3B42RT is significantly and positively correlated with that by rain gauge data. So, the evolutions of the rainfall change over time obtained by the two data are consistent. Results of correlation analyses and MODE method indicate that 3B42RT correctly shows the structure of the main rain belts during Typhoon Rananim (0414).