Satellite Aerosol Optical Depth over Vietnam - An Analysis from VIIRS and CALIOP Aerosol Products

Satellite aerosol products are useful to address a variety of questions relating to the atmosphere, climate change, air pollution, and human health. Thus, their evaluation followed by validation in different regions of the world can help in refining the products. In this study, VIIRS (2012–2015) and CALIPSO (2006–2015) aerosol products are analyzed and compared for seasonal trend and aerosol subtypes at Nghia Do, Nha Trang, and Bac Lieu AERONET stations located in the north, central, and southern regions of Vietnam, respectively. At Nghia Do station, VIIRS AOD captured the northern seasonal trends well with low errors, and high correlation coefficients. CALIPSO aerosol subtypes have shown polluted dust, biomass burning, polluted continental, clean continental, and desert dust coinciding with the northern climate conditions, agricultural burning, and long-range transport. At Nha Trang station, VIIRS AOD performed poorly with no seasonal trends, large errors, and low correlation coefficients. However, aerosol subtype analysis revealed marine aerosol, polluted continental, polluted dust, biomass burning, and desert dust events over the Nha Trang which are mostly explained by location, local climate conditions, and vegetation burning. For Bac Lieu station, VIIRS AOD quality is the lowest compared to AERONET AOD. No seasonal trend has been captured and the errors are extremely high in rainy and dry seasons at this station. CALIPSO aerosol subtypes are marine aerosol, polluted continental, polluted dust, biomass burning, and clean continental which could be explained by location, heat island, and local paddy rice seasonality. In overall, evaluation of VIIRS and CALIPSO aerosol products over Vietnam provides useful insights on their utility and potential applications in aerosol and air quality research.