Natural and Anthropogenically Influenced Isoprene Oxidation in Southeastern United States and Central Amazon

Author(s):Show less -

Yee, Lindsay D. ^[1] ; Isaacman-VanWertz, Gabriel ^[1] ; Wernis, Rebecca A. ^[2] ; Kreisberg, Nathan M. ^[3] ; Glasius, Marianne ^[4] ; Riva, Matthieu ^[5] ; Surratt, Jason D. ^[5] ; de Sa, Suzane S. ^[6] ; Martin, Scot T. ^{[6, 7]} ; Alexander, M. Lizabeth ^[8] ; Palm, Brett B. ^{[9, 10]} ; Hu, Weiwei ^{[9, 10]} ; Campuzano-Jost, Pedro ^{[9, 10]} ; Day, Douglas A. ^{[9, 10]} ; Jimenez, Jose L. ^{[9, 10]} ; Liu, Yingjun ^[6] ; Misztal, Pawel K. ^[1] ; Artaxo, Paulo ^[11] ; Viegas, Juarez ^[12] ; Manzi, Antonio ^[12] ; de Souza, Rodrigo A. F. ^[13] ; Edgerton, Eric S. ^[14] ; Baumann, Karsten ^[14] ; Goldstein, Allen H. ^{[1, 2]}

Affiliation:Show less -

^[1] Univ Calif Berkeley, Dept Environm Sci Policy & Management, Berkeley, CA 94720 - USA

^[2] Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 - USA

^[3] Aerosol Dynam Inc, Berkeley, CA 94710 - USA

^[4] Aarhus Univ, Dept Chem, DK-8000 Aarhus C - Denmark

^[5] Univ N Carolina, Dept Environm Sci & Engn, Gillings Sch Global Publ Hlth, Chapel Hill, NC 27599 - USA

^[6] Harvard Univ, Sch Engn & Appl Sci, Cambridge, MA 01451 - USA

^[7] Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 01451 - USA

^[8] Pacific Northwest Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 - USA

^[9] Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 - USA

^[10] Univ Colorado, Cooperat Inst Res Environm Sci CIRES, Boulder, CO 80309 - USA

^[11] Univ Sao Paulo, BR-05508020 Sao Paulo - Brazil

^[12] Inst Nacl de Pesquisas da Amazonia, BR-69060001 Manaus, Amazonas - Brazil

^[13] Univ Estado Amazonas, BR-69735000 Manaus, Amazonas - Brazil

^[14] Atmospher Res & Anal Inc, Cary, NC 27513 - USA

• Document type: Journal article
• Source: Environmental Science & Technology; v. 54, n. 10, p. 5980-5991, MAY 19 2020.
• Web of Science Citations: 1

Abstract

Anthropogenic emissions alter secondary organic aerosol (SOA) formation chemistry from naturally emitted isoprene. We use correlations of tracers and tracer ratios to provide new perspectives on sulfate, NOx, and particle acidity influencing isoprene-derived SOA in two isoprene-rich forested environments representing clean to polluted conditions-wet and dry seasons in central Amazonia and Southeastern U.S. summer. We used a semivolatile thermal desorption aerosol gas chromatograph (SV-TAG) and filter samplers to measure SOA tracers indicative of isoprene/HO2 (2-methyltetrols, C-5-alkene triols, 2-methyltetrol organosulfates) and isoprene/NOx (2-methylglyceric acid, 2-methylglyceric acid organosulfate) pathways. Summed concentrations of these tracers correlated with particulate sulfate spanning three orders of magnitude, suggesting that 1 mu g m(-3) reduction in sulfate corresponds with at least similar to 0.5 mu g m(-3) reduction in isoprene-derived SOA. We also find that isoprene/NOx pathway SOA mass primarily comprises organosulfates, similar to 97% in the Amazon and similar to 55% in Southeastern United States. We infer under natural conditions in high isoprene emission regions that preindustrial aerosol sulfate was almost exclusively isoprene-derived organosulfates, which are traditionally thought of as representative of an anthropogenic influence. We further report the first field observations showing that particle acidity correlates positively with 2-methylglyceric acid partitioning to the gas phase and negatively with the ratio of 2-methyltetrols to C-5-alkene triols. (AU)

• FAPESP's process: 13/05014-0 - GoAmazon: interactions of the urban plume of Manaus with biogenic forest emissions in Amazonia
• Grantee: Paulo Eduardo Artaxo Netto
• Support Opportunities: Research Program on Global Climate Change - Thematic Grants