气候变化领域集成服务门户(CCPortal): Contributions of biomass-burning; urban; and biogenic emissions to the concentrations and light-absorbing properties of particulate matter in central Amazonia during the dry season

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DOI	10.5194/acp-19-7973-2019
	Contributions of biomass-burning; urban; and biogenic emissions to the concentrations and light-absorbing properties of particulate matter in central Amazonia during the dry season
	De Sá S.S.; Rizzo L.V.; Palm B.B.; Campuzano-Jost P.; Day D.A.; Yee L.D.; Wernis R.; Isaacman-Vanwertz G.; Brito J.; Carbone S.; Liu Y.J.; Sedlacek A.; Springston S.; Goldstein A.H.; Barbosa H.M.J.; Lizabeth Alexander M.; Artaxo P.; Jimenez J.L.; Martin S.T.
发表日期	2019
ISSN	16807316
起始页码	7973
结束页码	8001
卷号	19 期号:12
英文摘要	Urbanization and deforestation have important impacts on atmospheric particulate matter (PM) over Amazonia. This study presents observations and analysis of PM1 concentration, composition, and optical properties in central Amazonia during the dry season, focusing on the anthropogenic impacts. The primary study site was located 70 km downwind of Manaus, a city of over 2 million people in Brazil, as part of the GoAmazon2014/5 experiment. A high-resolution time-of-flight aerosol mass spectrometer (AMS) provided data on PM1 composition, and aethalometer measurements were used to derive the absorption coefficient babs;BrC of brown carbon (BrC) at 370 nm. Non-refractory PM1 mass concentrations averaged 12.2 μgm-3 at the primary study site, dominated by organics (83 %), followed by sulfate (11 %). A decrease in babs;BrC was observed as the mass concentration of nitrogen-containing organic compounds decreased and the organic PM1 O V C ratio increased, suggesting atmospheric bleaching of the BrC components. The organic PM1 was separated into six different classes by positive-matrix factorization (PMF), and the mass absorption efficiency Eabs associated with each factor was estimated through multivariate linear regression of babs;BrC on the factor loadings. The largest Eabs values were associated with urban (2.04±0.14m2 g-1) and biomass-burning (0.82±0.04 to 1.50±0.07m2 g-1) sources. Together, these sources contributed at least 80% of babs;BrC while accounting for 30% to 40% of the organic PM1 mass concentration. In addition, a comparison of organic PM1 composition between wet and dry seasons revealed that only part of the 9-fold increase in mass concentration between the seasons can be attributed to biomass burning. Biomass-burning factor loadings increased by 30-fold, elevating its relative contribution to organic PM1 from about 10% in the wet season to 30% in the dry season. However, most of the PM1 mass (> 60 %) in both seasons was accounted for by biogenic secondary organic sources, which in turn showed an 8-fold seasonal increase in factor loadings. A combination of decreased wet deposition and increased emissions and oxidant concentrations, as well as a positive feedback on larger mass concentrations are thought to play a role in the observed increases. Furthermore, fuzzy c-means clustering identified three clusters, namely "baseline", "event", and "urban" to represent different pollution influences during the dry season. The baseline cluster, representing the dry season background, was associated with a mean mass concentration of 9±3 μgm-3. This concentration increased on average by 3 μgm-3 for both the urban and the event clusters. The event cluster, representing an increased influence of biomass burning and long-range transport of African volcanic emissions, was characterized by remarkably high sulfate concentrations. The urban cluster, representing the influence of Manaus emissions on top of the baseline, was characterized by an organic PM1 composition that differed from the other two clusters. The differences discussed suggest a shift in oxidation pathways as well as an accelerated oxidation cycle due to urban emissions, in agreement with findings for the wet season. © Author(s) 2019.
语种	英语
scopus关键词	biogenic emission; biomass burning; concentration (composition); deforestation; dry season; particulate matter; urban area; urbanization; Amazonia; Brazil
来源期刊	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/144332
作者单位	John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, United States; Department of Environmental Sciences, Universidade Federal de São Paulo, Diadema, São Paulo, Brazil; Department of Chemistry and Cooperative, Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, United States; Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, United States; Department of Civil and Environmental Engineering, University of California, Berkeley, Berkeley, CA, United States; Institute of Physics, University of São Paulo, São Paulo, Brazil; Brookhaven National Laboratory, Upton, NY, United States; Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, United States; Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA, United States; Department of Atmospheric Sciences, University of Washington, Seattle, WA, United States; Department of...
推荐引用方式 GB/T 7714	De Sá S.S.,Rizzo L.V.,Palm B.B.,et al. Contributions of biomass-burning; urban; and biogenic emissions to the concentrations and light-absorbing properties of particulate matter in central Amazonia during the dry season[J],2019,19(12).
APA	De Sá S.S..,Rizzo L.V..,Palm B.B..,Campuzano-Jost P..,Day D.A..,...&Martin S.T..(2019).Contributions of biomass-burning; urban; and biogenic emissions to the concentrations and light-absorbing properties of particulate matter in central Amazonia during the dry season.Atmospheric Chemistry and Physics,19(12).
MLA	De Sá S.S.,et al."Contributions of biomass-burning; urban; and biogenic emissions to the concentrations and light-absorbing properties of particulate matter in central Amazonia during the dry season".Atmospheric Chemistry and Physics 19.12(2019).