中文摘要：

地表太阳辐射是陆气能量交换过程中重要的物理参数和生态参数,利用卫星数据反演地表太阳辐射对于全面认识地表太阳辐射空间差异性和年际变化特征具有重要的意义。本文利用GMS-5静止气象卫星数据反演了中国区域1998-2002年地表太阳辐射值,在此基础上分析了我国地表太阳辐射的时空分布特征。结果表明：（1）青藏高原的地表太阳辐射最大,川黔地区最小,都位于北纬22~35°这一带;除川黔地区外,地表太阳辐射从东向西增强,西部随纬度升高而减小,东部以长江流域最小,向南北增加,西南最大,北部次之,至东北地区随纬度升高而减小;（2）各月地表太阳辐射量分布复杂,最小值都出现在12月,但最大值出现时间受雨季影响很大,珠江、长江一带主要在雨季过后的7月,华北、东北和青藏高原主要出现在雨季前的6月及5月,西南地区则在季风雨季前的4-5月;（3）5年来东部沿海地区地表太阳辐射增加了13.71%（＋4.37W/m2.a）,西藏高原地区地表太阳辐射减少了9.31%（-3.47W/m2.a）,全国地表太阳辐射平均减少了0.84%（-0.27W/m2.a）。

英文摘要：

Downward shortwave radiation（DSR） is an important physical and ecological parameter under the total energy exchange process between atmosphere and land surface.DSR retrieval from satellite data is of significance to be fully aware of the spatial variability and interannual variation features of this parameter.Based on DSR at surface retrieved from Geostationary Meteorological Satellite（GMS） 5 data over China from 1998 to 2002,the features of DSR spatio-temporal variation over China are comprehensive analyzed.The results show：（1） on the Nationwide,the maximum DSR is on Tibetan Plateau and the minimum value is over the Sichuan Basin and Guizhou,both the extreme values are located on the belt between 22°N to 35°N;apart from Sichuan Basin and Guizhou,DSR usually increases from East to West;DSR in West region decreases with the increase of latitude,while Yangtze River basin in East part has the lowest DSR;DSR increases from South to North,the maximum DSR is in North China,the second largest place is in South China,DSR decreases with latitude in Northeast China;（2） the distribution of monthly DSR is complicated;the minimum DSR happens in December,however the maximum DSR,controlled by the rainy season,is in July after the rainy season in Pearl and Yangtze River,May and June before the rainy season in South and Northeast China and Qinghai Tibetan Plateau,while April and May before the rainy season in Southwest China;（3）DSR over Southeastern coastal regions has increased by 13.71%（＋4.37W/m2·a）for those 5 years,while DSR over Southwestern Plateau has decreased by 9.31%（-3.47W/m2·a）;the overall average DSR over China has decreased by 0.84%（-0.27W/m2·a）.