中文摘要：

庞大的青藏高原不仅影响其周围的气候,也影响整个亚洲甚或全球的气候,而且本身还形成了独特的高原气候。但高原上气象观测站点极为稀少,降水资料奇缺,难以完整、深刻地认识高原降水的时空分布格局。选用热带降雨测量计划卫星（Tropical Rainfall Measuring Mission,TRMM）3B43月尺度降水率数据,并根据114个气象站点数据与TRMM数据的差额和克里格球形插值模型对原数据进行了修正,克服了原数据低值高估、高值低估的问题,并以此分析了青藏高原1998~2011年的多年平均降水的空间格局与季节分布特征。研究结果证实了青藏高原降水的空间格局呈现自东南向西北递减、自南向北逐渐减少的基本分布规律,包括喜马拉雅山北坡雨影区、高原西北部＂寒旱核心＂的存在;还发现了一些新的规律,包括阿里喀喇昆仑山少雨区、高原腹地相对湿润区、横断山脉中心相对干旱区等。高原降水的季节分配不均匀,其中,西、北部春（3~5月）、秋（9~11月）和冬（12~2月）的降水占全年降水比例均为20%~30%,夏季（6~8月）降水稍多,比例为30%~40%;东南部降水主要集中在夏季,比例高达40%~60%,春、秋降水比例为20%~30%,冬季降水比例低于10%。

英文摘要：

As the highest plateau on the Earth,the Tibetan Plateau influences the climate of its adjacent regions and even the whole Asia or the whole world.However,knowledge on its precipitation pattern is very limited due to the sparsely distributed rain gauges,especially in its western part.Besides,the plateau is geomorphologically complicated,making it even harder to carry out conventional meteorological observations.Satellite data for precipitation estimation has the advantage of full spatial coverage and can be used to solve the problem of climatic data shortage.In this article,the 0.25-degree resolution Tropical Rainfall Measuring Mission（TRMM） 3B43 product from 1998 to 2011 was analyzed to depict spatial and seasonal precipitation patterns over the plateau.But,TRMM 3B43 data often overestimate the amount of rainfall in the arid areas and underestimate rainfall in the extremely humid regions.Kriging interpolation method was chosen to improve the accuracy of TRMM data based on the difference between observational and TRMM-derived data.The results confirmed the generally recognized spatial patterns of precipitation decreasing from southeast to northwest and from south to north,the existence of rain shadow in the northern flank of the Himalaya Mountains and the cold-arid core of the Eurasia.Some new spatial patterns of precipitation were also revealed,such as the dry region in the Ali-Karakoram Mountains,a relatively humid region in the heartland of the plateau and a comparatively arid region in the central part of the Hengduan Mountains.Seasonal patterns of precipitation in the Tibetan Plateau vary greatly from southeast to northwest.The ratios of precipitation in Spring（from March to May）,Autumn（from September to November） and Winter（from December to February） to annual precipitation are all 20~ 30% in the northwest of the plateau,while the ratio for Summer（from June to August） is 30%~40%,a little more than that in other seasons.In the southeast,precipitation occurs mainly in summer（40%~60%）,so