title: Soil humic-like organic compounds in prescribed fire emissions using nuclear magnetic resonance spectroscopy.
abstract: Here we present the chemical characterization of the water-soluble organic carbon fraction of atmospheric aerosol collected during a prescribed fire burn in relation to soil organic matter and biomass combustion. Using nuclear magnetic resonance spectroscopy, we observed that humic-like substances in fire emissions have been associated with soil organic matter rather than biomass. Using a chemical mass balance model, we estimated that soil organic matter may contribute up to 41% of organic hydrogen and up to 27% of water-soluble organic carbon in fire emissions. Dust particles, when mixed with fresh combustion emissions, substantially enhances the atmospheric oxidative capacity, particle formation and microphysical properties of clouds influencing the climatic responses of atmospheric aeroso. Owing to the large emissions of combustion aerosol during fires, the release of dust particles from soil surfaces that are subjected to intense heating and shear stress has, so far, been lacking.
authors.affiliation: Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, 4301 W. Markham St., Little Rock, AR 72205, USA. ikavouras@uams.edu
authors.forename: M-C
authors.initials: MC
authors.lastname: Chalbot
authors.forename: G
authors.initials: G
authors.lastname: Nikolich
authors.forename: V
authors.initials: V
authors.lastname: Etyemezian
authors.forename: D W
authors.initials: DW
authors.lastname: Dubois
authors.forename: J
authors.initials: J
authors.lastname: King
authors.forename: D
authors.initials: D
authors.lastname: Shafer
authors.forename: G
authors.initials: G
authors.lastname: Gamboa da Costa
authors.forename: J F
authors.initials: JF
authors.lastname: Hinton
authors.forename: I G
authors.initials: IG
authors.lastname: Kavouras
mesh_terms: D000336:Aerosols / Q000032:analysis* / Q000737:chemistry; D000393:Air Pollutants / Q000032:analysis*; D018533:Biomass; D004391:Dust / Q000032:analysis*; D004784:Environmental Monitoring; D005390:Fires; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D012987:Soil / Q000737:chemistry*
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D004391:Dust; D012987:Soil
keywords: Aerosol; Biomass burning; Mineral dust; Nuclear magnetic resonance; Organic carbon; Wildfires