Using VIIRS Aerosol Products to Assess the Impact of Wildfire Emissions on Observed Air Quality in the Mid-Atlantic Region

Smoke particles and trace gases emitted from wildfires are a growing contributor to poor air quality events in the Mid-Atlantic region of the United States. Many of the highest observed ozone (O₃) and fine particulate matter (PM_2.5) days now occur when plumes from large upwind fires reach the Mid-Atlantic. Ozone and PM_2.5 are criteria air pollutants that are harmful for human health, particularly for “sensitive” groups such as children, senior citizens, and individuals with respiratory or cardiovascular diseases. Wildfire emissions plumes contain nitrogen oxides and hydrocarbons, which are precursors for O₃ production, and primary PM_2.5 in the form of smoke aerosols. Large wildfires are becoming more common in the continental United States, Alaska, and Canada due to extended periods of drought and hot weather, leading to increased incidences of emissions plumes reaching the Mid-Atlantic and in turn, contributing to locally high O₃ and PM_2.5. High spatial resolution aerosol products from the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument on the Suomi National Polar-orbiting Partnership (SNPP) satellite can pinpoint when smoke plumes are present in the Mid-Atlantic region. VIIRS aerosol optical thickness (AOT) at 750 m resolution is a quantitative measure of smoke aerosols, and the VIIRS smoke mask provides a qualitative indicator of smoky air. These aerosol satellite data provide support for analysis of associated air quality events, including for Exceptional Event demonstrations. Case studies of recent wildfire-affected high O₃ and PM_2.5 days in the Mid-Atlantic will be presented, demonstrating the presence of wildfire emissions plumes using VIIRS aerosol products. Future steps will also be discussed, including a pilot study to utilize high resolution aerosol products from the GOES-16 satellite during the 2018 fire season to help air quality forecasters predict when wildfire plumes will impact the Mid-Atlantic