1. The document analyzes aerosol measurements from Higashi-Osaka, Japan to classify aerosol types into six categories and correlate aerosol optical thickness (AOT) with particulate matter (PM). 2. Aerosols were classified using k-means clustering of AERONET data into categories like dust, biomass burning, and pollution. Approximate size distributions were proposed to characterize each category. 3. Correlating AOT and PM measurements improved PM2.5 estimation from AOT by considering anthropogenic versus dust aerosols separately. 4. Aerosol retrieval algorithms were developed using the proposed aerosol models and properties to interpret MODIS data for heavy