中文摘要：

基于观察每日的 降水数据，从 UK 的上面的空气温度和海表面温度数据遇见了的每月的 gridded 雷送办公室哈德利中心，来自在东英吉利亚和 NCEP/NCAR 月刊分析数据的大学的气候的研究单位的每月的表面空气温度，这研究在 19612010 期间在中国和北半球的中间高度的纬度上调查小雨事件的空间、时间的变化，并且讨论在 c 之间的关系在华东上的小雨事件显示 3.0%/10 的一个减少的趋势一在里面夏天和冬季一半年。在西北中国上， 4.1%/10 的一个增加的趋势一是在冬季发现半年，但是在夏天没有趋势半年。使用的实验直角的功能(文件结束) 分析，在北半球的中间高度的纬度上的小雨事件的开始的二个主要部件在夏天和冬季一半显示出长时间规模变化，这被发现年。为年两个都描绘的夏天和冬季一半的第一个文件结束模式( EOF1s )在象西北中国一样的北美洲和南部的欧洲上的小雨事件的长期的增加(除了在夏天半年)，并且在大多数欧亚大陆上的长期的减少(中央欧洲，东方欧洲，诺思亚洲和华东)。为夏天的第二个文件结束模式( EOF2 )半年证明小雨事件在北美洲，南部的欧洲和华南上增加，但是 45 湩牣慥敳?瑡爠瑡獥漠?向北在欧亚大陆上减少?┷愠摮㈠?┶瀠牥ㄠ鴿??鞪銮???????嶰??????鴿????????徬?鳪颟?龜逿???龜蒠?鶝麪鰿?侲鬿鉂?隮???????颣陌??????龜鴿????龜??鎪疞???徬??斪?鎬亘箖疞??? 鞪 ？？

英文摘要：

Based on observed daily precipitation data, monthly gridded radiosonde upper air temperature and sea surface temperature data from the UK Met Office Hadley Centre, monthly surface air temperature from the Climatic Research Unit at the University of East Anglia and the NCEP/NCAR monthly reanalysis data, this study investigates the spatial and temporal variations of light rain events over China and the mid-high latitudes of the Northern Hemisphere during 1961-2010, and discusses the relationship between the change of light rain events and atmospheric stability, sea surface temperature and atmospheric circulation. The light rain events over East China display a decreasing trend of 3.0%/10 a in summer and winter half years. Over Northwest China, an increasing trend of 4.1%/10 a is found in winter half years, but there is no trend in summer half years. Using empirical orthogonal function （EOF） analysis, it is found that the first two principal components of light rain events over the mid-high latitudes of the Northern Hemisphere show long time scale variations in summer and winter half years. The first EOF modes （EOFls） for summer and winter half years both depict a long-term increase in light rain events over North America and Southern Europe as well as Northwest China （except in summer half years）, and a long-term decrease over most of the Eurasia （Central Europe, Eastern Europe, North Asia and East China）. The second EOF mode （EOF2） for summer half year shows that light rain events increase over North America, Southern Europe and South China, but decrease over Eurasia north of 45~N from 1961 to early 1980s, while the trends reverse from late 1980s to 2010. The second EOF mode （EOF2） for winter half years indicates that light rain events increase over North America and South and North China, but decrease over Eurasia north of 40~N from 1961 to early 1980s, while the trends reverse from late 1980s to 2009. Correlation analysis and linear regression analysis suggest that EOFls may be related to