Collaborative Research: Sizing Up the Smoke--Evaluating and Improving Our Ability to Predict Aged Wildfire Aerosol Size Distributions

Atmospheric And Environmental Research Inc, Lexington MA

Investigators

Abstract

This research is focused on studying the aging of emissions from biomass burning. Small particles emitted from biomass combustion can react in the atmosphere, changing their size, number, and composition. These aging processes will be modeled and the model results will be tested against actual data from field campaigns. The following questions will be investigated: (1) What are the chemical processes that, when combined with the dispersion and coagulation of biomass-burning emissions, capture the evolution of aerosol size and number concentrations seen in the laboratory and the field? (2) Are the secondary organic aerosol (SOA) formation rates and size-distribution changes measured in lab experiments consistent with the field measurements of aerosol aging? If they are not, can we determine why (e.g. lack of continuous dilution or wall losses in chamber experiments)? (3) What properties most strongly determine the aged biomass-burning aerosol size and number? E.g. total mass emission flux, fresh particle size, fuel type, modified combustion efficiency, wind speed, fire area, vertical mixing depth, sunlight. (4) Can the variability in aged biomass-burning aerosol size and number be captured by a simple parameterization that is a function of the most important of the above properties?