SmokePath Explorer, a New Smoke Management Tool for California

Prescribed fires are one of the most effective tools to reduce hazardous fuels (vegetation) buildup contributing to severe wildfires in the western U.S. In the coming years, California is expected to significantly increase the use of prescribed fires. Any vegetation burning emits smoke and harmful air pollutants. However, prescribed fires can minimize smoke impacts on downwind air quality, especially in comparison to uncontrolled wildfires. To conduct prescribed fires effectively, land and air quality managers need information and tools to support smoke management.

In this project funded by CAL FIRE, we developed a turnkey, online decision-support tool named SmokePath Explorer for prescribed fire planning and wildfire response. The tool allows users to specify a time window and a location for a planned prescribed fire or current wildfire, and view the fire weather statistics and the probability of potential downwind smoke impacts. Based on 20 years (2001-2020) of high-resolution (2 km) climatological data for California and Nevada, fire weather statistics were computed, and air transport data were created through hourly air parcel trajectory modeling. For user-specified location, years, and months or weeks of year, the SmokePath Explorer uses these results to:

1. Determine the probability of air parcel transport downwind
2. Display the historical summary of weather parameters relevant to fire and smoke conditions (e.g., relative humidity, temperature, mixing height)
3. Identify the potential receptor locations by integrating air parcel transport probability with population, education facility, healthcare facility, and ZIP code data

Air and land managers can use the SmokePath Explorer to plan prescribed fires. This will allow for more timely public messaging regarding potential smoke impacts, and proactive mitigation efforts to assist at-risk populations.

In addition to the tool, the project team has identified multiple case studies based on past prescribed fire projects and wildfires to evaluate the transport modeling results and establish guidance for using the tool. These cases include pile burns, broadcast burns, and typical wildfires in different air basins across California. Results of these case studies and the tool will be presented.