10th International Aerosol Conference
September 2 - September 7, 2018
America's Center Convention Complex
St. Louis, Missouri, USA

Abstract View


Photochemical Model Estimated Fire Impacts on Aerosol Evaluated with Field Studies and Routine Data Sources

KIRK BAKER, United States Environmental Protection Agency

     Abstract Number: 524
     Working Group: Aerosol Transport and Transformation

Abstract
Highly instrumented field studies provide a unique opportunity to evaluate multiple aspects of photochemical grid model representation of fire emissions, dispersion, and chemical evolution. Fuel information and burn area for a specific fire coupled with near-fire and downwind chemical measurements provides information needed to constrain model predicted fire plume transport and chemical evolution of important pollutants such as particulate matter (PM2.5) that have deleterious health effects. Most local to regional scale field campaigns to date have made relatively few transects through plumes from fires with well characterized fuel type and consumption. While more comprehensive field studies are being planned for 2018 and beyond (WE-CAN and FIREX), existing measurement data from multiple field campaigns including 2013 SEAC4RS, satellite data, and routine surface networks are used to assess how a regulatory modeling system captures fire impacts on local to regional scale PM2.5. A comparison of Community Multiscale Air Quality (CMAQ) model estimated speciated PM2.5 from specific fires with routine surface measurements at rural locations in proximity to the 2013 Rim fire, 2011 Wallow fire, and 2011 Flint Hills fires indicate PM2.5 organic carbon tends to be overpredicted at rural surface sites downwind from the 2011 Flint Hills prescribed fires while results were mixed at rural sites downwind of the 2013 Rim fire and 2011 Wallow fire. These results suggest differences in fuel characterization (e.g., emission factors, emissions speciation, burn period, etc.) between these areas may contribute to differences in model prediction. Remotely sensed AOD and aircraft transects made downwind of the 2013 Rim fire suggest the model does well at predicting local to regional scale transport and also the vertical extent of the plume. However, the model tends to underestimate regional downwind AOD compared with satellites and ground-based estimates during the Rim fire period.