Abstract View
A Bird’s Eye View of Sampling Forest Fire Smoke: Using Drone-Based Measurements of Prescribed Burning to Help Close the Gap between Laboratory and Wild-Fire Smoke Studies
NATHAN KREISBERG, Deep Sengupta, Robert Weber, James D.A. Butler, Yutong Liang, Paul Van Rooy, Afsara Tasnia, Farrah Haeri, Coty Jen, Emre Ozen, Edward Gonzalez, Jason Kriesel, Kevin K. Schwarm, Daniel Foster, Rebecca A. Sugrue, Mitchell R. Spearrin, Thomas W. Kirchstetter, Kelley Barsanti, Allen Goldstein, Aerosol Dynamics Inc.
Abstract Number: 571
Working Group: Wildfire Aerosols
Abstract
The incidence of forest fires in the western US is predicted to increase from ongoing changes in climate leading to an increased need to understand the atmospheric burden of biomass burning. The use of prescribed burns to reduce excess fuel loads is also likely to greatly increase to compensate for the historic preference to suppress fires of all sizes. Laboratory based studies to characterize the specific types of emissions from various fuel types (e.g., trees, shrubs and grasses) has led to inventories of chemical emission factors under small scale and necessarily simplified combustion conditions practicably achievable.
Prescribed burns can serve to help close the gap between somewhat artificial laboratory studies and uncontrolled wildfires if the differences in fuels and fire state (flame vs smolder) between them can be sufficiently characterized. A near perfect opportunity to explore this approach occurred at the Blodgett Forest Research Station where an ongoing forest management study involved the use of prescribed burns for comparison with alternative management techniques. Located in the Sierra foothills near the El Dorado National Forest, the Blodgett forest is mixed conifer forest that has not experienced fire for 100 years and thus fairly represents a large portion of the western US national and state forests.
A sample collection and sensor laden drone package was designed, built, and deployed between April 20th and 23rd, 2021 as part of the scheduled prescribed burns. A unique aspect of this study is the pre- and post-burn fuel inventory conducted by UCB that offers the prospect of tying specific smoke plumes sampled with known fuel types consumed by fire. Both particulate and gas samples were acquired in conjunction with real-time gas (CO2, CO and NO) and BC measurements gathered at 1Hz throughout each flight. The samples will be analyzed by multi-dimensional GCMS while the real-time measurements provide a means of estimating specific emission factors for individual compounds while also providing insights into the plume structures themselves. Supplemental visual/thermal and high temporal resolution CO measurements were conducted on two additional drones. Initial findings of this multi-drone sampling strategy will be reported with examples of the real-time sensor and imaging data.