JULY 2007: Fire and biofuel contributions to annual mean aerosol mass concentrations in the United States

We estimate the contributions from biomass burning (summer wildfires, other fires, residential biofuel, and industrial biofuel) to seasonal and annual aerosol concentrations in the United States. Our approach is to use correlation statistics between total carbonaceous (TC) and non-soil potassium (ns-K) aerosol mass concentrations for 2001-2004 from the nationwide IMPROVE network of surface sites, together with satellite fire data.

Figure shows annual mean contributions of individual burnings to TC aerosol concentrations in the United States for 2001-2004. Numbers on top of each panel give the mean concentrations over the western and eastern United States separated at 95oW. Summer wildfires and other fires including non-summer wildfires and prescribed burns are largest contributors to annual TC aerosol concentrations in the United States. Residential and industrial biofuels make also important regional contributions. Total annual mean fine aerosol concentrations from biomass burning average 1.2 and 1.6 ug m-3 in the west and east, respectively, contributing about 50% of observed annual mean TC concentrations in both regions and accounting for 30% (west) and 20% (east) of total observed fine aerosol concentrations. Biomass burning is thus an important contributor to U.S. air quality degradation which is likely to grow in the future. A full description of this work is given in Park et al. [2007].