title: Light absorption properties and radiative effects of primary organic aerosol emissions.
abstract: Organic aerosols (OAs) in the atmosphere affect Earth's energy budget by not only scattering but also absorbing solar radiation due to the presence of the so-called "brown carbon" (BrC) component. However, the absorptivities of OAs are not represented or are poorly represented in current climate and chemical transport models. In this study, we provide a method to constrain the BrC absorptivity at the emission inventory level using recent laboratory and field observations. We review available measurements of the light-absorbing primary OA (POA), and quantify the wavelength-dependent imaginary refractive indices (kOA, the fundamental optical parameter determining the particle's absorptivity) and their uncertainties for the bulk POA emitted from biomass/biofuel, lignite, propane, and oil combustion sources. In particular, we parametrize the kOA of biomass/biofuel combustion sources as a function of the black carbon (BC)-to-OA ratio, indicating that the absorptive properties of POA depend strongly on burning conditions. The derived fuel-type-based kOA profiles are incorporated into a global carbonaceous aerosol emission inventory, and the integrated kOA values of sectoral and total POA emissions are presented. Results of a simple radiative transfer model show that the POA absorptivity warms the atmosphere significantly and leads to ∼27% reduction in the amount of the net global average POA cooling compared to results from the nonabsorbing assumption.
authors: †Energy Systems Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States.
authors: Zifeng
authors: Z
authors: Lu
authors: †Energy Systems Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States.
authors: David G
authors: DG
authors: Streets
authors: †Energy Systems Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States.
authors: Ekbordin
authors: E
authors: Winijkul
authors: †Energy Systems Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States.
authors: Fang
authors: F
authors: Yan
authors: ‡Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, 205 North Mathews Avenue, Urbana, Illinois 61801, United States.
authors: Yanju
authors: Y
authors: Chen
authors: ‡Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, 205 North Mathews Avenue, Urbana, Illinois 61801, United States.
authors: Tami C
authors: TC
authors: Bond
authors: §Environmental Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States.
authors: Yan
authors: Y
authors: Feng
authors: ∥Earth and Environmental Sciences Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545, United States.
authors: Manvendra K
authors: MK
authors: Dubey
authors: ∥Earth and Environmental Sciences Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545, United States.
authors: Shang
authors: S
authors: Liu
authors: ⊥National Center for Environmental Assessment, U.S. EPA, 4930 Page Road, Research Triangle Park, Durham, North Carolina 27709, United States.
authors: Joseph P
authors: JP
authors: Pinto
authors: #Department of Chemical and Biochemical Engineering, The University of Iowa, 4133 Seamans Center, Iowa City, Iowa 52242, United States.
authors: Gregory R
authors: GR
authors: Carmichael
mesh_terms: D000336:Aerosols / Q000032:analysis* / Q000737:chemistry*; D000393:Air Pollutants / Q000737:chemistry*; D001272:Atmosphere / Q000737:chemistry; D056804:Biofuels; D018533:Biomass; D002244:Carbon / Q000737:chemistry*; D002980:Climate; D008027:Light; D008962:Models, Theoretical; D012031:Refractometry; D053260:Soot / Q000737:chemistry
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D056804:Biofuels; D053260:Soot; D002244:Carbon