Improving spatial resolution of PM2.5 measurements during wildfires

Publication Date


Document Type


Publication Title

Atmospheric Pollution Research








This study proposes an approach to improve the spatial resolution of ground-level concentrations of PM2.5 that is required to assess health risks associated with exposure to pollutants released during wildfires. We use this approach to analyze the impact on air quality of the wildfire complex consisting of the Atlas, Nuns, Tubbs, Pocket, and Redwood Valley fires in northern California that started on October 8, 2017 and the Camp Fire in northern California that was first reported on November 8, 2018. The PM2.5 concentrations measured in populated areas downwind of these fires were well above the 24-h standard of 35 μg/m3 during several days of both fires. To estimate health risks at locations where ground-based monitors did not provide sufficient spatial coverage we first estimate the emissions from the fires by fitting concentration estimates from two models, a Lagrangian model and a segmented plume dispersion model, to corresponding concentrations from ground monitors. We also use a power law model to fit the measured PM2.5 concentrations to the ratio of aerosol optical depth (AOD) to planetary boundary layer measured by the Moderate Resolution Imaging Spectroradiometer (MODIS) carried by NASA's Terra and Aqua satellites. Dispersion model estimates are then combined with estimates from the AOD model to compute ground-level concentrations at a resolution of 1 km. Kriged residuals between estimates from the combined model and measured PM2.5 concentrations are then added to obtain high resolution maps that can be used for exposure studies.

Funding Number


Funding Sponsor

National Aeronautics and Space Administration


Dispersion modeling, Kriging, PM2.5, Satellite AOD, Spatial resolution, Wildfires emissions


Meteorology and Climate Science