Based on relevant MODIS data and the 6S atmospheric radiation transfer model, aerosol direct radiation effects ( ADRE) on the surface of the Yangtze River Delta and the top layer of the atmosphere were simulated and calculated, and then validated for accuracy with reference to the measured data by CE-318 of the Beichen Building Station of the Nanjing University of Information Science&Technology. On such a basis, analysis was conducted of spatio-temporal distribution of ADRE in the Yangtze River Delta region, Results show that the MODIS data could be used to inverse ADRE on land sur-face and on top of the atmosphere with results approximate to the measured data, reaching 0. 92 and 0. 95 in fitting accura-cy ( R2 ) . In terms of spatial distribution and variation, ADREs on land surface (-31. 60--20. 54 W·m-2 ) and on top of the atmosphere (-3. 48--2. 61 W·m-2 ) tended to be similar with absolute values being high in the north and lower to-wards the south. The ADREs in Suzhou, Wuxi and Changzhou of South Jiangsu increased significantly;In terms of tempo-ral variation, absolute ADREs fluctuated downwards year by year, varying in the range of -21. 78--5. 94 and -2. 45--0. 73 W·m-2 , respectively, on land surface and on top of the atmosphere, and varied quite significantly with the season in Jiangsu and Shanghai and relatively less in Zhejiang in the range of-10-0 W·m-2 on land surface and-1-0 W·m-2 on top of the atmosphere.%以长三角地区为研究区,基于MODIS卫星遥感数据和6S大气辐射传输模型,模拟计算长三角地区地表和大气层顶的气溶胶直接辐射效应(aerosol direct radiation effect,ADRE),并利用南京信息工程大学北辰楼站点CE-318实测数据进行精度验证,在此基础上分析长三角地区气溶胶直接辐射效应的时空分布特征.结果表明,利用MODIS数据反演的地表ADRE、大气层顶ADRE与实测值的拟合精度R2分别为0.92和0.95.在空间上,地表与大气层顶直接辐射效应值的分布区域与变化趋势在整体上趋于一致,其绝对值均呈现北高南低的态势,地表ADRE为-31.60～-20.54 W·m-2、大气层顶ADRE为-3.48～-2.61 W·m-2之间的ADRE绝对值高值区主要集中在北部,尤其在江苏南部的苏州、无锡和常州地区,气溶胶辐射效应显著增大;在时间上,ADRE绝对值的年变化呈波动下降趋势,地表和大气层顶ADRE均值分别在-21.78～-5.94和-2.45～-0.73 W·m-2之间.其中江苏、上海地区气溶胶辐射效应的季节性变化明显,浙江地区辐射效应的季节性差异较小,地表ADRE变化范围大多分布在-10～0 W·m-2区间,大气层顶ADRE变化范围大多分布在-1～0 W·m-2区间.
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