中文摘要：

利用热带测雨卫星（TRMM）上搭载的测雨雷达（PR）探测结果和中国40°N以南地区约430个台站雨量计观测结果,分析研究了1998 2005年中国南方地区这两种降水资料气候分布的异同。研究结果表明两种降水资料在2.5°空间水平分辨率上,所描述的中国南方降水率气候分布在多年年平均和季平均上具有较好的一致性,但在降水率极值和极值区范围大小等细节上两者还存在一定的差异,主要是地面雨量计结果相对PR结果偏高,其中中国南方50%以上地区两者相差在1 mm/d以内、30%的地区两者相差在1-2 mm/d,夏季差异可超过2 mm/d。对两种降水资料差异的原因分析表明,地面雨量计空间分布密度是影响两者差异的决定性因素,当格子内雨量计超过6个时,两者的相关系数大于0.7;夏季两种降水资料的相关性都比其他季节差,不论格子内的雨量计数量多与少;对流降水多发地区,两种降水资料之间的差异大于层云降水多发地。利用PR探测结果对夏季青藏高原多年月平均降水率分布及高原东、西部的降水特点的分析表明,6月高原东部出现2 mm/d左右的降水区,而在7和8月1 mm/d的降水区域基本覆盖了除高原西部以外的整个高原,其中高原中部地区出现降水率近3mm/d的大值区。月降水距平的时间演变表明,高原降水偏少月份要多于偏多月份。

英文摘要：

The rain rates measured by the TRMM PR and observed by the 430 rain gauges in the southern China from January 1998 to December 2005 are compared in the multi-time scale in order to study the difference between these two precipitation datasels.The results suggest a significantly consistent precipitation distribution at the 2.5 degree horizontal resolution with one another in either the multiyear average scale or the multiyear seasonal mean scale but with a certain difference existing in the extreme value and its covering region.Generally,the mean rain rate obtained by rain gauges are relatively higher than that by the PR.The region with the difference less than 1 mm/d occupies over 50%in the southern China while about 30%of the southern China shows the difference of about 1 - 2 mm/d.Such the difference reaches more than 2 mm/d during the summer in the most part of the southern China.The analysis indicates that the difference between these two datasets is mainly determined by the spatial density of the rain gauges.The correlation coefficient is higher than 0.7 when the number of rain gauges in a grid is over 6.However,both the datasets show less correlation in summer than that in the other seasons,whatever be the number of rain gauges in a grid.The difference between these two is also larger in the region with high frequency of convective precipitation than that with frequent stratiform precipitation.By using the TRMM PR measurements,the distribution of the monthly mean rain rate averaged over the 8 years in the Tibetan Plateau during summer is also investigated in this paper.The results show that there exist 2 mm/d precipitation areas in the eastern plateau in June,while in July and August 1 mm/d rain rate areas cover great part of the plateau（except for the western plateau）.And in the center of the plateau a rain rate of over 3 mm/d appears. Time series of monthly rain rate departures show the months of less rainfall are more than those of more rainfall in the plateau.