Simultaneous Retrieval of Aerosol Optical Thickness and Exponent of Junge Power-law From AATSR L1B

An iterative algorithm is used to simultaneously determining the aerosol optical thickness(AOT) and the exponent of Junge power-law from AATSR L1B reflectance data of channel 0.87um and 1.61um over Taiwan Strait, in this paper. Considering the variation of aerosol complex refractive index(ACRI) with wavelength, the retrieval of aerosol is implemented under constant and variable ACRI. Suppose the MODIS aerosol product values are accurate. For constant ACRI, there are 47.87% and 96.96% pixels with acceptable retrieval AOT and the exponent of Junge power law value, respectively. Likewise, there are 61.02% and 67.01% pixels for variable ACRI. Compared with the retrieval error under constant ACRI, there are 91.79% and 8.3% pixels with smaller AOT and Junge power-law index retrieval error under variable ACRI, respectively. Besides, the precision of AOD retrieved under constant ACRI is equivalent with variable ACRI when AOT product is less than 0.3. However, both constant and variable ACRI can obtain consistant spatial and temporal distribution of AOT.