Retrieval of Aerosol optical thickness and size distribution from PARASOL in Pearl River Delta area

Abstract

AOTs(Aerosol optical thicknesses) and aerosol size distribution functions in Pearl River Delta area are derived from PARASOL (Polarization and Anisotropy of Reflectances for Atmospheric Science coupled with Observations from a LIDAR)multi-directional, multi-spectral polarized signals. Based on analyzing the products of AERONET(Aerosol Robotic Network), aerosol size distribution function and complex refractive index over Pearl River Delta area are received. After that, the particular aerosol model is abstracted. The land surface polarized contribution is calculated using semi empirical model as a function of surface type and NDVI, and the pure atmospheric contribution is computed with a radiative transfer code. Compared with the products of the ground-based AERONET, the derived AOTs are underestimated against AERONET measurement. The retrieved size distribution for the radii bigger than 0.2 micron is also underestimated due to that polarization is insensitive to coarse model aerosol.