中国地区云光学厚度和云滴有效半径变化趋势

摘要

利用ISCCP最新的D2云气候资料集和MODIS云的资料,给出中国地区云的光学厚度和云滴有效半径的分布特征；分别对季节平均和年平均时间序列进行线性趋势分析,并进行了显著性检验.结果表明:夏季云的光学厚度和有效半径的变化趋势最显著.结合云量变化情况,可发现云滴有效半径的变化对云光学厚度的影响可能在夏季最大,也就是说,气溶胶的间接气候效应可能在夏季最强；云量、云光学厚度和云滴有效半径的变化也表明长江以南地区和青藏高原地区可能是气溶胶间接气候效应比较显著的地区.中国地区冰云光学厚度与有效直径的相关具有很强的区域特征,说明冰云的微物理机制比水云更复杂.%The temporal and spatial characteristics of clouds over China are analyzed by using the ISCCP (International Satellite Cloud Climatology Project) monthly mean D2 data and MODIS (MODerate-resolution Imaging Spectroradiometer) cloud data. The results show that over the past 20 years, the changes in cloud effective radius have the greatest effect on cloud optical thickness during summer, which means that the indirect effect of aerosol on climate may be the strongest during summer. The analysis of cloud optical thickness and effective radius changes also shows that the Yangtze River region and the Qinghai-Tibet Plateau region may be the areas influenced the most prominently by the indirect climatic effects of aerosols. Besides, the ice cloud optical thickness and effective diameter are associated with strong regional characteristics in China, which indicates that micro-physical mechanisms in ice clouds are more complex than water clouds.