Evaluating the potential for application of MODIS satellite data for urban air quality monitoring in Vietnam

Abstract

Using satellite remote sensing data in combining with other technologies (i.e. sensor, ground-based system) for surface air quality monitoring has been considered as one of promising approaches for urban air quality management in future smart cities. This study assessed the accuracy of latest collection (Collection 6.1 - C6.1) of MODerate resolution Imaging Spectroradiometer (MODIS) satellite aerosol optical depth (AOD) retrieval by Dark Target (DT) algorithm at 3 and 10 km spatial resolutions in urban areas in Vietnam. Collocated Aqua and Terra MODIS C6.1 AOD at 550 nm were inter-compared against AOD from two AERONET stations in Vietnam, estimated throughout the satellite passes (± 1 h). Two investigated AERONET stations are Nghia Do (inland urban) and Bac Lieu (coastal urban) with the studying periods of 2010 - 2016 and 2010 - 2017, respectively. Our findings showed that the MODIS DT 3km were performed worse than the MODIS DT 10 km product in urban areas. Furthermore, all two MODIS AOD DT products showed better performance at inland urban site than coastal urban site. In general, both MODIS products were able to follow the monthly-mean AERONET AODs. The peak of aerosol loading at the investigated urban sites could be properly attributed to the combination of the monsoon effect and biomass burning activities. The mean aerosol loading of rainy season appeared to be lowest in the year, which could be attributed to the fact that the frequent rain washes out the dust in the atmosphere.