 This paper proposes a new methodology to estimate ground-level PM2.5 concentrations using satellite-derived 500M AOD data. The methodology combines the simplified high-resolution MODIS aerosol retrieval algorithm, CERA, AOD product with meteorological variables such as PBLH, RH, WS, and temp extracted from weather research and forecasting, WRF, a simulation to depict the spatiotemporal dynamics in the PM2.5 AOD relationship. The GTWR model provides ground-level PM2.5 concentrations with 500M resolution at the MODIS satellites overpass moments twice a day, which can be used for air quality monitoring and haze tracking at the urban and regional scale. This article was authored by Yang Bai, Lee Sin Woo, Kai Chen, and others.