Among all the VIIRS EDRs, most relevant to the air quality and public health applications are the Aerosol Optical Thickness (AOT) and Atmospheric Suspended Matter (ASM) EDRs. The accuracy in deriving surface Particulate Matter (PM) concentration and particle size parameter is intrinsically amenable to the accuracy of satellite AOT retrievals. To enrich NPP's applied science aspect of VIIRS aerosol EDRs, we collaborate with scientists from Centers for Disease Control and Prevention, EPA, and multi-institutional project Infusing Satellite Data into Environmental Applications (IDEA) to conduct the following tasks: (a) assess and improve the surface reflectance characterization scheme used in the VIIRS algorithm for AOT retrievals; (b) evaluate and enhance the VIIRS AOT retrieval in dusty conditions; (c) use a novel (and published) approach to conduct the independent retrieval of AOT and surface PM for evaluating and improving the VIIRS ASM EDR; and (d) infuse the VIIRS AOT, our independent estimate of surface PM, and the VIIRS ASM EDR with the IDEA and National Environmental Public Health Tracking Network (NEPHTN) for air quality and public health applications. The information content that VIIRS brings to IDEA will be further used for the diary of air quality on the U.S. air quality weblog. Because the air quality and public health applications most often are targeted at regional scale in nature, all our proposed tasks will focus on problems and improvements of VIIRS aerosol EDRs in specific regions (such as over the semi-arid western U.S) and/or atmospheric conditions (such as during dust event). Our approach for conducting these tasks is based upon our published studies that improved MODIS c005 aerosol product in dusty atmosphere and/or semi-arid region. The approach will integrate the VIIRS clear-sky reflectance data with a chemistry transport model (GEOS-chem) to conduct the independent and self-consistent retrieval of AOT and surface PM concentration. Given that the VIIRS aerosol algorithm has a strong heritage from MODIS, and currently MODIS algorithm doesn't retrieve the ASM amount at the surface, we believe that together with the ground-based aerosol data, our proposed tasks (under the framework of an independent research-oriented retrieval algorithm focusing at regional scale and case studies) will provide an in-depth evaluation of and constructive improvement to the VIIRS AOT and ASM EDRs. We will share our progresses with the VIIRS operational algorithm team, and work together with them to enhance the accuracy of aerosol EDRs and to demonstrate the potential of these EDRs for air quality monitoring and public health surveillance. This proposed project is based upon the PI and Co-Is' 30+ years' research experience in the forefront of remote sensing of aerosols and air quality. The investigators' interdisciplinary collaborations with partners from EPA, Centers for Disease Control and Prevention, and NASA GSFC will strengthen this proposed work and broaden the NPP's applied science component. The proposed tasks will also be leveraged from PI and Co-Is existing projects that heavily use the MODIS and MISR aerosol products for air quality application.