MODIS high-resolution MAIAC aerosol product: Global validation and analysis

Abstract

This paper attempt to verify the accuracy of the Multi-Angle Implementation of Atmospheric Correction (MAIAC) aerosol optical depth (AOD) product on a global scale using AOD measurements during 2000–2019 at 332 Aerosol Robotic Network (AERONET) sites. The results indicate that MAIAC AOD retrievals are highly correlated with ground-based AOD measurements. The correlation coefficients (R) are greater than 0.8 at more than 68% of AERONET sites. Meanwhile, the performance of MAIAC AOD retrievals in different climate zones is also investigated. The accuracy of MAIAC AOD retrievals is high (within expected error (EE) = 87.49% and 83.15%) in the regions of tropical rainforest climate and tropical open forest climate. Then, the uncertainties and estimation deviation of MAIAC AOD retrievals in various land-cover-types are analyzed. The results find that the MAIAC AOD retrievals show high correlation with aerosol measurements in the forest (within EE > 95%), while the poor accuracy is always observed in the barren areas (within EE = 62.56%, RMSE = 0.12). The uncertainty of the MAIAC AOD retrievals is not only related to the satellite and solar geometries, but also depends on the aerosol conditions, which become larger with the increase of aerosol loading and Ångstrom exponent (AE). Finally, the spatial variations of AOD values over the world are investigated. High AOD values are mainly distributed in Central Africa, Saudi Arabia, Southern Asia and China.