Effective aerosol optical thickness retrieval algorithm using modis 500 metre data

Abstract

Aerosol estimation from satellite data is crucial for the air quality assessment, visibility estimation, and climate modelling. Numerous retrieval algorithms have been developed for aerosol optical thickness estimation but there are still uncertainties in estimation due to several factors that need to be addressed for the development of an effective retrieval algorithm. Therefore, the main goal of this study is to develop an effective aerosol retrieval algorithm using Moderate Resolution Imaging Spectroradiometer 500 metre data considering the effects of different Radiative Transfer codes, surface reflectance estimation techniques, local aerosol models, and atmospheric transmission contributions. The aerosol estimation algorithm has been developed using several processing steps include i) estimation of aerosol reflectance from satellite data, ii) local aerosol models characterization using aerosol inversion product, iii) estimation of aerosol reflectance as function of aerosol optical thickness using different Radiative Transfer codes and direct method, iv) retrieval of aerosol optical thickness by comparing the residual of aerosol reflectance between satellite data and Radiative Transfer codes using Look-up Tables based on optimal spectral shape fitting function, and v) validation of retrieved aerosol optical thickness with in-situ ground measurement. Results indicate that aerosol optical thickness can be successfully retrieved from the satellite data using Second Simulation of a Satellite Signal in the Solar Spectrum vector code, 2-channel of Moderate Resolution Imaging Spectroradiometer data, and surface reflectance derived from the Radiative Transfer code based atmospheric correction using continental and desert aerosol model together. The proposed algorithm is very effective and retrieved aerosol optical thickness from Moderate Resolution Imaging Spectroradiometer 500 metre data with the accuracy of 96% and low uncertainty for the both study sites. This finding highlights the potential of this algorithm to retrieve aerosol optical thickness from satellite data with high accuracy and good spatial information compared to the 10 kilometres satellite aerosol product.