The Science Behind the AirNow Sensor Data Pilot

January 21, 2021

The Science Behind the AirNow Sensor Data Pilot

The U.S. Environmental Protection Agency (EPA) and the U.S. Forest Service (USFS) conducted the AirNow Sensor Data Pilot during the 2020 fire season to provide the public with air sensor information on the air pollutant, fine particulate matter (PM2.5), especially during smoke events from fires. The sensor data is shown on the Fire and Smoke Map, part of the popular website.

The air sensors are among several new additions to the Fire and Smoke Map, made possible with innovative technical approaches developed and applied by EPA to compare sensor data with data from regulatory grade monitors and temporary monitors provided by EPA, USFS, states, tribes, and local air quality agencies. This webinar will provide an overview of the AirNow Sensor Data Pilot and the development of the U.S.-wide correction equation for PurpleAir PM2.5 sensor data and its appropriateness for correcting PM2.5 measurements during smoke events.


* Welcome and Introduction, Tim Watkins, Director, EPA's Center for Environmental Measurement and Modeling (CEMM)

* Adding Low-Cost Sensor Data to the AirNow Fire and Smoke Map, Ron Evans, EPA's Office of Air Quality Planning and Standards (OAQPS); Sim Larkin, U.S. Forest Service (USFS)

* Technical Overview of the Development and Performance Validation of U.S.-Wide Correction Equation for PurpleAir Sensor Data, Drs. Karoline Johnson Barkjohn, Amara Holder, and Andrea Clements, EPA's Office of Research and Development (ORD)

* Q&A