气溶胶光学厚度（AOD）是表征气溶胶含量及大气污染程度的关键因素。利用CALIPSO卫星level 2气溶胶廓线产品，分析2009年至2018年全球范围典型区域内AOD的时空变化特征及其变化趋势。结果表明：全球范围的AOD表现出一定的时空差异性。在空间尺度上，AOD高值中心主要分布在印度、沙特阿拉伯等地区；在时间尺度上，也存在明显的季节差异性。印度、沙特阿拉伯及中国北方等典型地区在MAM和DJF时期达到AOD峰值，巴西则在JJA时期达到AOD峰值。每个典型地区也存在显著的AOD趋势差异，印度地区AOD上升趋势最强。

Aerosol optical depth （AOD） is a key factor for characterizing aerosol content and atmospheric pollution. In this study， level 2 aerosol profile products of the CALIPSO satellite were used to analyze the temporal and spatial variation characteristics and trends of AOD in specific regions worldwide from 2009 to 2018. Results show that AOD has a certain temporal and spatial difference in different areas. On the spatial scale， high AOD value centers are mainly distributed in India， Saudi Arabia， and other regions； moreover， on the temporal scale， noticeable seasonal differences exist. Specific regions such as India， Saudi Arabia， and northern China show peak AOD during the MAM and DJF periods， while Brazil peak during the JJA period. Moreover， significant AOD trend differences exist in each typical region， with the strongest upward trend in India.