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Moschos V, Christensen C, Mouton M, Fiddler MN, Isolabella T, Mazzei F, Massabò D, Turpin BJ, Bililign S, Surratt JD. Quantifying the Light-Absorption Properties and Molecular Composition of Brown Carbon Aerosol from Sub-Saharan African Biomass Combustion. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:4268-4280. [PMID: 38393751 PMCID: PMC10919089 DOI: 10.1021/acs.est.3c09378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 01/19/2024] [Accepted: 01/22/2024] [Indexed: 02/25/2024]
Abstract
Sub-Saharan Africa is a hotspot for biomass burning (BB)-derived carbonaceous aerosols, including light-absorbing organic (brown) carbon (BrC). However, the chemically complex nature of BrC in BB aerosols from this region is not fully understood. We generated smoke in a chamber through smoldering combustion of common sub-Saharan African biomass fuels (hardwoods, cow dung, savanna grass, and leaves). We quantified aethalometer-based, real-time light-absorption properties of BrC-containing organic-rich BB aerosols, accounting for variations in wavelength, fuel type, relative humidity, and photochemical aging conditions. In filter samples collected from the chamber and Botswana in the winter, we identified 182 BrC species, classified into lignin pyrolysis products, nitroaromatics, coumarins, stilbenes, and flavonoids. Using an extensive set of standards, we determined species-specific mass and emission factors. Our analysis revealed a linear relationship between the combined BrC species contribution to chamber-measured BB aerosol mass (0.4-14%) and the mass-absorption cross-section at 370 nm (0.2-2.2 m2 g-1). Hierarchical clustering resolved key molecular-level components from the BrC matrix, with photochemically aged emissions from leaf and cow-dung burning showing BrC fingerprints similar to those found in Botswana aerosols. These quantitative findings could potentially help refine climate model predictions, aid in source apportionment, and inform effective air quality management policies for human health and the global climate.
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Affiliation(s)
- Vaios Moschos
- Department
of Physics, College of Science and Technology, North Carolina A&T State University, Greensboro, North Carolina 27411, United States
- Department
of Environmental Sciences and Engineering, Gillings School of Global
Public Health, The University of North Carolina
at Chapel Hill, Chapel
Hill, North Carolina 27516, United States
| | - Cade Christensen
- Department
of Chemistry, College of Arts and Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Megan Mouton
- Department
of Applied Sciences and Technology, College of Science and Technology, North Carolina A&T State University, Greensboro, North Carolina 27411, United States
| | - Marc N. Fiddler
- Department
of Chemistry, College of Science and Technology, North Carolina A&T State University, Greensboro, North Carolina 27411, United States
| | - Tommaso Isolabella
- Department
of Physics, University of Genoa, 16146 Genoa, Italy
- National
Institute of Nuclear Physics (INFN), 16146 Genoa, Italy
| | - Federico Mazzei
- Department
of Physics, University of Genoa, 16146 Genoa, Italy
| | - Dario Massabò
- Department
of Physics, University of Genoa, 16146 Genoa, Italy
| | - Barbara J. Turpin
- Department
of Environmental Sciences and Engineering, Gillings School of Global
Public Health, The University of North Carolina
at Chapel Hill, Chapel
Hill, North Carolina 27516, United States
| | - Solomon Bililign
- Department
of Physics, College of Science and Technology, North Carolina A&T State University, Greensboro, North Carolina 27411, United States
- Department
of Applied Sciences and Technology, College of Science and Technology, North Carolina A&T State University, Greensboro, North Carolina 27411, United States
| | - Jason D. Surratt
- Department
of Environmental Sciences and Engineering, Gillings School of Global
Public Health, The University of North Carolina
at Chapel Hill, Chapel
Hill, North Carolina 27516, United States
- Department
of Chemistry, College of Arts and Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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Zhong Q, Schutgens N, van der Werf GR, Takemura T, van Noije T, Mielonen T, Checa-Garcia R, Lohmann U, Kirkevåg A, Olivié DJ, Kokkola H, Matsui H, Kipling Z, Ginoux P, Le Sager P, Rémy S, Bian H, Chin M, Zhang K, Bauer SE, Tsigaridis K. Threefold reduction of modeled uncertainty in direct radiative effects over biomass burning regions by constraining absorbing aerosols. SCIENCE ADVANCES 2023; 9:eadi3568. [PMID: 38039365 PMCID: PMC10691779 DOI: 10.1126/sciadv.adi3568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 11/02/2023] [Indexed: 12/03/2023]
Abstract
Absorbing aerosols emitted from biomass burning (BB) greatly affect the radiation balance, cloudiness, and circulation over tropical regions. Assessments of these impacts rely heavily on the modeled aerosol absorption from poorly constrained global models and thus exhibit large uncertainties. By combining the AeroCom model ensemble with satellite and in situ observations, we provide constraints on the aerosol absorption optical depth (AAOD) over the Amazon and Africa. Our approach enables identification of error contributions from emission, lifetime, and MAC (mass absorption coefficient) per model, with MAC and emission dominating the AAOD errors over Amazon and Africa, respectively. In addition to primary emissions, our analysis suggests substantial formation of secondary organic aerosols over the Amazon but not over Africa. Furthermore, we find that differences in direct aerosol radiative effects between models decrease by threefold over the BB source and outflow regions after correcting the identified errors. This highlights the potential to greatly reduce the uncertainty in the most uncertain radiative forcing agent.
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Affiliation(s)
- Qirui Zhong
- Department of Earth Sciences, Vrije Universiteit, Amsterdam, Netherlands
| | - Nick Schutgens
- Department of Earth Sciences, Vrije Universiteit, Amsterdam, Netherlands
| | | | - Toshihiko Takemura
- Research Institute for Applied Mechanics, Kyushu University, Fukuoka, Japan
| | - Twan van Noije
- Royal Netherlands Meteorological Institute, De Bilt, Netherlands
| | | | - Ramiro Checa-Garcia
- Laboratoire des Sciences du Climat et de l'Environnement, IPSL, Gif-sur-Yvette, France
- European Centre for Medium-Range Weather Forecasts, Reading, UK
| | - Ulrike Lohmann
- Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
| | - Alf Kirkevåg
- Norwegian Meteorological Institute, Oslo, Norway
| | | | | | - Hitoshi Matsui
- Graduate School of Environmental Studies, Nagoya University, Nagoya, Japan
| | - Zak Kipling
- European Centre for Medium-Range Weather Forecasts, Reading, UK
| | - Paul Ginoux
- NOAA Geophysical Fluid Dynamics Laboratory, Princeton, NJ, USA
| | | | | | - Huisheng Bian
- Goddard Earth Sciences Technology and Research (GESTAR) II, University of Maryland at Baltimore County, Baltimore, MD, USA
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - Mian Chin
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - Kai Zhang
- Pacific Northwest National Laboratory, Richland, WA, USA
| | - Susanne E. Bauer
- NASA Goddard Institute for Space Studies, New York City, NY, USA
- Center for Climate Systems Research, Columbia University, New York City, NY, USA
| | - Kostas Tsigaridis
- NASA Goddard Institute for Space Studies, New York City, NY, USA
- Center for Climate Systems Research, Columbia University, New York City, NY, USA
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