Investigating Biomass Burning Aerosol in North America

Fires and the aerosols that they emit have important implications for air quality, visibility, health, and climate, but the abundance and properties of carbonaceous aerosol (both black carbon and organic carbon) from biomass burning remain uncertain and poorly constrained. To explore this, we compare three years (2012-2014) of GEOS-Chem model simulations driven by a variety of fire emissions inventories (Global Fire Emissions Database version 4 (GFED4), Quick Fire Emission Dataset (QFED), Fire INventory from NCAR (FINN), and Global Fire Assimilation System (GFAS)). This allows us to bracket the uncertainty in smoke aerosol associated with emissions. We quantify the spread in black carbon (BC) and organic aerosol (OA) concentrations simulated using these various inventories and compare these to observations from two fire-influenced aircraft campaigns in North America (ARCTAS and DC3) and surface concentration data from the Interagency Monitoring of Protected Visual Environments (IMPROVE) network. We also explore how fire emissions impact the aerosol optical depth (AOD) simulated over North America and how various emissions inventories impact our ability to capture the MODIS AOD observations. Finally, we consider whether the addition of secondary organic aerosol (SOA) formation in fire plumes, as constrained by the recent FIREX lab experiments, improves our simulation.