1University of Montana, Department of Chemistry, Missoula, MT, USA
2USDA Forest Service, Fire Sciences Laboratory, Missoula, MT, USA
3University of Miami, Rosenstiel School of Marine and Atmospheric Science, Miami, FL, USA
4School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
5Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ, USA
6National Center for Atmospheric Research, Boulder, CO, USA
7University of Colorado, Department of Atmospheric and Oceanic Sciences, Boulder, CO, USA
Abstract. We report airborne measurements of emission factors (EF) for trace gases and PM2.5 made in southern Mexico in March of 2006 on 6 crop residue fires, 3 tropical dry forest fires, 8 savanna fires, 1 garbage fire, and 7 mountain pine-oak forest fires. The savanna fire EF were measured early in the local dry season and when compared to EF measured late in the African dry season they were at least 1.7 times larger for NOx, NH3, H2, and most non-methane organic compounds. Our measurements suggest that urban deposition and high windspeed may also be associated with significantly elevated NOx EF. When considering all fires sampled, the percentage of particles containing soot increased from 15 to 60 % as the modified combustion efficiency increased from 0.88 to 0.98. We estimate that about 175 Tg of fuel was consumed by open burning of biomass and garbage and as biofuel (mainly wood cooking fires) in Mexico in 2006. Combining the fuel consumption estimates with our EF measurements suggests that the above combustion sources account for a large fraction of the reactive trace gases and more than 90 % of the total primary, fine carbonaceous particles emitted by all combustion sources in Mexico.