Comment on amt-2022-91

Abstract

Aerosol spatial distribution obtained from the satellite sensor is a critical point to understand regional aerosol environment, anthropogenic aerosol emissions, and global climate change. In this study, the performance of aerosol optical depth (AOD) retrieval from the Directional Polarimetric Camera (DPC)/GaoFen-5 by using the Generalized Retrieval of Atmosphere and Surface Properties (GRASP) algorithm was evaluated on a global basis for the first time. The results showed that the DPC GRASP/Model scheme, which used several aerosol-type mixings, achieved good performance. By compared with AERONET observations, the correlation coefficient (R), normalized mean square error, and Expect Error (EE%) were 0.8982, 0.1008, and 83.16 %, respectively. The scattering angle, number of averaged pixels in retrieval units, and radiative and polarized fitting residuals showed impacts on the results of AOD retrieval in the DPC GRASP/Model. From the most of AERONET sites, the R and EE% were larger than ~0.9 and ~80 %. Compared with MODIS products, the spatial and temporal variations of AOD could be caught by the DPC observations with the GRASP/Model, and compared with the MODIS Dark Target algorithm, the DPC GRASP/Model AOD also showed a good performance. The above findings validated the ability of DPC sensor to monitor aerosols. It would contribute to the development of aerosol parameter retrieval from multi-angular polarized sensors in the future.