Observations of sesquiterpenes and their oxidation products in central Amazonia during the wet and dry seasons
Year: 2018
Type: article
Abstract: . Biogenic volatile organic compounds (BVOCs) from the Amazon forest region represent the largest source of organic carbon emissions to the atmosphere globally. These BVOC emissions dominantly consist of volatile and intermediate-volatility terpenoid compounds that undergo chemical transformations in the atmosphere to form oxygenated condensable gases and secondary organic aerosol (SOA). We collected quartz filter samples with 12 h time resolution and performed hourly in situ measurements with a semi-volatile thermal desorption aerosol gas chromatograph (SV-TAG) at a rural site (T3) located to the west of the urban center of Manaus, Brazil as part of the Green Ocean Amazon (GoAmazon2014/5) field campaign to measure intermediate-volatility and semi-volatile BVOCs and their oxidation products during the wet and dry seasons. We speciated and quantified 30 sesquiterpenes and 4 diterpenes with mean concentrations in the range 0.01–6.04 ng m−3 (1–670 ppqv). We estimate that sesquiterpenes contribute approximately 14 and 12 % to the total reactive loss of O3 via reaction with isoprene or terpenes during the wet and dry seasons, respectively. This is reduced from ∼ 50–70 % for within-canopy reactive O3 loss attributed to the ozonolysis of highly reactive sesquiterpenes (e.g., β-caryophyllene) that are reacted away before reaching our measurement site. We further identify a suite of their oxidation products in the gas and particle phases and explore their role in biogenic SOA formation in the central Amazon region. Synthesized authentic standards were also used to quantify gas- and particle-phase oxidation products derived from β-caryophyllene. Using tracer-based scaling methods for these products, we roughly estimate that sesquiterpene oxidation contributes at least 0.4–5 % (median 1 %) of total submicron OA mass. However, this is likely a low-end estimate, as evidence for additional unaccounted sesquiterpenes and their oxidation products clearly exists. By comparing our field data to laboratory-based sesquiterpene oxidation experiments we confirm that more than 40 additional observed compounds produced through sesquiterpene oxidation are present in Amazonian SOA, warranting further efforts towards more complete quantification.
Authors: Lindsay D. Yee, Gabriel Isaacman-VanWertz, Rebecca A. Wernis, Meng Meng, Ventura Rivera, Nathan M. Kreisberg, Susanne V. Hering, Mads S. Bering, Marianne Glasius, Mary Alice Upshur, Ariana Gray Bé, Regan J. Thomson, Franz M. Geiger, John H. Offenberg, Michael Lewandowski, Ivan Kourtchev, Markus Kalberer, Suzane de Sá, Scot T. Martin, M. Lizabeth Alexander, Brett B. Palm, Weiwei Hu, Pedro Campuzano-Jost, Douglas A. Day, Jose L. Jimenez, Yingjun Liu, Karena A. McKinney, Paulo Artaxo, Juarez Viegas, Antonio Manzi, Maria B. Oliveira, Rodrigo de Souza, Luiz A. T. Machado, Karla Longo, Allen H. Goldstein
Institutions: University of California, Berkeley, Virginia Tech, University of Toronto, Aerosol Dynamics (United States), Aarhus University, Northwestern University, Environmental Protection Agency, University of Cambridge, Harvard University, Pacific Northwest National Laboratory, Environmental Molecular Sciences Laboratory, Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Colby College, Universidade de São Paulo, Instituto Nacional de Pesquisas da Amazônia, Universidade do Estado do Amazonas, Instituto Nacional de Pesquisas Espaciais
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
SDGs: Climate action, Life on land
Open Access status: gold
Estimated APC paid: $1,725
Funders: National Science Foundation, U.S. Department of Energy, National Aeronautics and Space Administration, U.S. Environmental Protection Agency, Alexander von Humboldt-Stiftung, University of California Berkeley, Northwestern University, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Fundação de Amparo à Pesquisa do Estado do Amazonas, Instituto Nacional de Pesquisas da Amazônia, Office of Science, Natural Environment Research Council, Division of Chemistry, Biological and Environmental Research
Awards: G1186038202, INVESTIGATING SECONDARY AEROSOL PROCESSES IN THE AMAZON THROUGH MOLECULAR-LEVEL CHARACTERIZATION OF SEMI-VOLATILE ORGANICS, Graduate Research Fellowship Program, G4594396776, TAS::89 0222::TAS NEW PHASE I SBIR; TITLE: AN ULTRAFINE FOCUSING SYSTEM TO SEPARATE PARTICULATE AND GASEOUS CONSTITUENTS OF ATMOSPHERIC AEROSOLS; PI, G528737020, Surfaces of Secondary Organic Aerosol Particles, G581965161, UNDERSTANDING THE APPLICABILITY OF GAS/PARTICLE PARTITIONING THEORY TO SOA USING NOVEL CHEMICALLY-SPECIATED PARTITIONING MEASUREMENTS, GoAmazon 2014 Contributions of Biogenic Volatile Organic Compounds to Organic Aerosol Formation in the Presence and Absence of Anthropogenic Pollution, G5976853421, G6036295616, UNDERSTANDING THE APPLICABILITY OF GAS/PARTICLE PARTITIONING THEORY TO SOA USING NOVEL CHEMICALLY-SPECIATED PARTITIONING MEASUREMENTS, G650162323, G6915139076, G7317432133, G8202023883
OpenAlex ID: W2789119787