Abstract: How to use the measurement from the visible channel of Chinese Fengyun-2C geostationary satellite to retrieve aerosol optical depth (AOD) is discussed. By calculating mean surface reflectance at the same local time of each day in one month, the randomicity of the estimated surface reflectance can be reduced. The influence of different values of AOD assumed in the cleanest days on the quality of final AOD product is analyzed. In addition, the data in May 2008 was used to test the proposed algorithm and the results were compared with the AOD product from six AERONET sites in East Asian and MODIS AOD product respectively. Last, the error sources were analyzed in the retrieval of AOD from FY2C satellite, and the corresponding possible schemes to decrease the error influence and improve the quality of FY2C AOD product were investigated. The comparison indicates that in East Asian the AOD product can display the pattern of aerosol distribution, but overestimates the values of AOD in southwest of China and low latitude areas, and underestimates the values of AOD in east of China.

Key words: aerosol optical depth, surface reflectance, FY2C, AERONET, MODIS

摘要： 探讨利用中国风云2C静止卫星可见光资料反演气溶胶光学厚度(AOD)的数值方法。通过计算一个月中每日同一时刻平均地表反射率来降低地表反射率估计的随机性, 讨论了该方法中对清洁天AOD值的不同假设对结果的影响。将2008年5月由风云2C可见光资料反演得到的AOD产品分别与东亚6个AERONET站点的AOD产品和MODIS的AOD产品进行了比较, 分析了风云2C卫星的AOD产品算法的误差来源和降低误差影响以及改善产品质量的方案。结果对比表明, 在东亚地区利用风云2C可见光资料反演的AOD产 品可以展示气溶胶的分布样式, 但是目前的算法高估了中国西南部地区和低纬度一些地区的AOD值而低估了中国东部地区的AOD值。

关键词: 气溶胶光学厚度, 地表反射率, 风云2C静止卫星, AERONET, MODIS