基于MODIS数据反演江浙皖地区气溶胶光学厚度

气溶胶是气候变化和大气污染的重要影响因素。人们发现卫星遥感为大面积获取气溶胶光学厚度提供了手段,同时卫星遥感的气溶胶光学厚度弥补了地面观测空间覆盖不足的缺陷。文章首先介绍了使用暗像元法反演气溶胶光学厚度的算法和计算流程,利用传统的暗像元法和改进的暗像元法(即V5.2算法)反演江浙皖地区(29～33°N;116～120°E)气溶胶光学厚度的空间分布,并对两种算法所得结果进行比较与分析。结果表明:暗像元法基本可以反映出该区域气溶胶光学厚度的空间分布特点,尤其是在浓密植被区卫星反演得到的结果与(AERONET)太阳光度计的观测值基本相近。但是在城市地区,该算法得到的结果与观测值存在一定的偏差,有待于进一步改善。

Retrieval of Aerosol Optical Depth over Jiangsu-Zhejiang-Anhui Areas using MODIS Data

Method and calculation process of dense dark vegetation method which is used to retrieve aerosol optical depth was introduced.MODIS data by traditional DDV algorithm and improved DDV algorithm was dealt with for retrieval of spatial distribution of AOD over Jiangsu-Zhejiang-Anhui areas.The inverse method was validated with AERONET solar direct radiance measurement.Results showed that the AOD obtained by both methods in the dense vegetation region were basically in consistent with the results from AERONET.However there was a certain bias between the results obtained by both methods and observations from AERONET in urban areas,which need to be further improved.