The AQS Data Mart is a database that contains all of the information from the AQS system. It is a storehouse of air quality information that allows users to make queries of unlimited quantities of data. The Data Mart also includes information from the EPA?s substance and facility registry systems.

The Air Quality System (AQS) database contains measurements of air pollutant concentrations from throughout the United States and its territories. The measurements include both criteria air pollutants and hazardous air pollutants.

The Air Quality System (AQS) database contains measurements of air pollutant concentrations from throughout the United States and its territories. The measurements include both criteria air pollutants and hazardous air pollutants.

AQS data is a publicly available dataset, which is part of this study. This data can be found on EPA website https://aqs.epa.gov/aqsweb/airdata/download_files.html (accessed on 1 April 2023). PA data is a 3rd party data and restrictions apply to the availability of these data. Data was obtained from Purple Air and are available from PurpleAir API https://community.purpleair.com/t/making-api-calls-with-the-purpleair-api/180 (accessed on 1 April 2023) with the permission of Purple Air. HMS smoke plume data is publicly available and can be downloaded at Office of Satellite and Product Operations website https://www.ospo.noaa.gov (accessed on 1 April 2023). The codes to download and analyze data in this paper is available at this GitHub repo https://github.com/hyang199723/PAFusion (uploaded on 30 June 2023). This dataset is associated with the following publication: Yang, H., S. Ruiz-Suarez, B. Reich, Y. Guan, and A. Rappold. A data fusion approach to assessing the contribution of wildland fire smoke to fine particulate matter in California. Remote Sensing. MDPI, Basel, SWITZERLAND, 15(17): 1, (2023).

Ambient concentrations of most requested pollutants from the national ambient air quality monitoring networks stored in the Air Quality System (AQS).

Ambient concentrations of most requested pollutants from the national ambient air quality monitoring networks stored in the Air Quality System (AQS).

AirNow is a collaboration between EPA, and othe federal, state and local agencies to provide complete and real-time air quality information.

AirNow is a collaboration between EPA, and othe federal, state and local agencies to provide complete and real-time air quality information.