An Evaluation of Two Decades of Aerosol Optical Depth Retrievals from MODIS over Australia

We present an evaluation of Aerosol Optical Depth (AOD) retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS) over Australia covering period 2001–2020. focus on Deep Blue (DB) and Multi-Angle Implementation Atmospheric Correction (MAIAC) algorithms, showing how these compare to one another in time space. further employ speciated AOD estimates Copernicus Monitoring Service (CAMS) reanalyses help diagnose aerosol types hence sources. Considering as a whole, monthly mean AODs show similar temporal behaviour, with well-defined seasonal peak Austral summer. However, excepting periods intense biomass burning activity, MAIAC values are systematically higher than their DB counterparts by, average, 50%. Decomposing into maps, patterns behaviour distinct differences, larger dynamic range AOD, markedly (?AOD?0.1) northern southeastern regions during winter This is counter-balanced by typically smaller across Australian interior. Site level comparisons all available 2 data Robotic Network (AERONET) sites operational study that tends marginally outperform terms correlation (RMAIAC = 0.71, RDB 0.65) root-mean-square error (RMSEMAIAC 0.065, RMSEDB 0.072). To probe this further, we classify according predominant surface type within 25 km radius. analysis shows MAIAC’s advantage retained for R but RMSE. For (Bare, comprising just 1.2% Australia) performance both algorithms relatively poor, 0.403, 0.332).