Significant overestimation of global aerosol optical thickness by MODIS over land  

作　　者：XIA Xiang'ao 

机构地区：[1]Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China

出　　处：《Chinese Science Bulletin》2006年第23期2905-2912,共8页

基　　金：The research is supported by the National Natural Science Foundation of China(Grant Nos.40305002,40333029 and 40520120071).

摘　　要：Global aerosol optical thickness (AOT) data over land obtained from the Moderate Resolu-tion Imaging Spectroradiometer (MODIS) are evaluated through comparisons with AOT data retrieved by Aerosol Robotic Network (AERONET). In general, MODIS overestimates AOT except at a few AERONET sites in Africa and eastern Asia. MODIS/AOTs are, on average, larger than AERONET/AOTs by 0.041 and 0.090 at 470 nm and 660 nm, respectively. The AOT bias at 660 nm is significantly correlated to the surface reflectance at 2130 nm. Both facts suggest that the underestimation of the surface reflectance is the principal reason for this bias at 660 nm. To use the MODIS/AOT at 470 nm is strongly recommended because it is much more reliable than the AOT at 660 nm.Global aerosol optical thickness （AOT） data over land obtained from the Moderate Resolution Imaging Spectroradiometer （MODIS） are evaluated through comparisons with AOT data retrieved by Aerosol Robotic Network （AERONET）. In general, MODIS overestimates AOT except at a few AERONET sites in Africa and eastern Asia. MODIS/AOTs are, on average, larger than AERONET/AOTs by 0.041 and 0.090 at 470 nm and 660 nm, respectively. The AOT bias at 660 nm is significantly correlated to the surface reflectance at 2130 nm. Both facts suggest that the underestimation of the surface reflectance is the principal reason for this bias at 660 nm. To use the MODIS/AOT at 470 nm is strongly recommended because it is much more reliable than the AOT at 660 nm.

关 键 词：MODIS AOT 重要评估 整体气溶胶光学厚度 主要原因 

分 类 号：O648.18[理学—物理化学]