中国西南地区气溶胶光学厚度的时空特征

Characteristics of aerosol optical depth distributions over southwest China

采用MODIS卫星遥感产品研究西南地区气溶胶季节变化,并对成都和香格里拉两站2008年的太阳光度计观测资料进行分析。结果表明西南地区气溶胶光学厚度(AOD Aerosol Optical Depth)全年呈西低东高的地理分布特征,但东西部季节变化特征不同:西南地区东部AOD有春季最大,秋冬次之,夏季最小的演变特征,并且在四川盆地,黔、渝、湘交界和广西中部有三个明显的AOD高值区。西南地区西部AOD有春季最大,夏秋次之,冬季最小的演变特征,无明显高值区。太阳光度计资料分析表明,成都地区AOD日变化呈准双峰型,香格里拉AOD日变化呈上升趋势。

The characteristics and seasonal changes of the aerosol optical depth（AOD）distribution of the southwest China were analyzed by using MODIS products and sun-photometer CE318 observations at Chengdu and Shangrila in 2008.The results showed the main geographical distribution feature of AOD from MODIS that was characterized by higher AOD in the west and lower in the east throughout the year.The seasonal variations are different between the eastern and western parts of southwest China.The AOD value in eastern part has shown the evolution features with the maximum in spring,next in autumn and winter,the minimum in summer.Three obviously high value areas of AOD were located at the Sichuan Basin,the juncture of Guizhou,Chongqing,Hunan provinces and the middle of Guangxi.The AOD in western part has shown the features with the maximum in spring,next in summer and autumn,the minimum in winter,and there were no significantly high value areas.From daily sun photometer data analysis it has been found that the changes of AOD in Chengdu from sunrise to sunset were quasi-bimodal,but there were upward trend in Shangrila region.