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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Characterization of a real-time tracer for isoprene epoxydiols-derived secondary organic aerosol (IEPOX-SOA) from aerosol mass spectrometer measurements

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Hu, W. W. [1, 2] ; Campuzano-Jost, P. [1, 2] ; Palm, B. B. [1, 2] ; Day, D. A. [2, 1] ; Ortega, A. M. [2, 3] ; Hayes, P. L. [1, 2] ; Krechmer, J. E. [2, 1] ; Chen, Q. [4, 5] ; Kuwata, M. [4, 6] ; Liu, Y. J. [4] ; de Sa, S. S. [4] ; McKinney, K. [4] ; Martin, S. T. [4] ; Hu, M. [5] ; Budisulistiorini, S. H. [7] ; Riva, M. [7] ; Surratt, J. D. [7] ; St Clair, J. M. [8] ; Isaacman-Van Wertz, G. [9] ; Yee, L. D. [9] ; Goldstein, A. H. [9, 10] ; Carbone, S. [11] ; Brito, J. [11] ; Artaxo, P. [11] ; de Gouw, J. A. [12, 1, 2] ; Koss, A. [1, 12] ; Wisthaler, A. [13, 14] ; Mikoviny, T. [13] ; Karl, T. [15] ; Kaser, L. [14, 16] ; Jud, W. [14] ; Hansel, A. [14] ; Docherty, K. S. [17] ; Alexander, M. L. [18] ; Robinson, N. H. [19] ; Coe, H. [19] ; Allan, J. D. [20, 19] ; Canagaratna, M. R. [21] ; Paulot, F. [22, 23] ; Jimenez, J. L. [1, 2]
Número total de Autores: 40
Afiliação do(s) autor(es):
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[1] Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 - USA
[2] Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 - USA
[3] Univ Colorado, Dept Atmospher & Ocean Sci, Boulder, CO - USA
[4] Harvard Univ, Sch Engn & Appl Sci, Cambridge, MA 02138 - USA
[5] Peking Univ, Coll Environm Sci & Engn, State Key Joint Lab Environm Simulat & Pollut Con, Beijing 100871 - Peoples R China
[6] Nanyang Technol Univ, Earth Observ Singapore, Singapore 639798 - Singapore
[7] Univ N Carolina, Dept Environm Sci & Engn, Gillings Sch Global Publ Hlth, Chapel Hill, NC - USA
[8] CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 - USA
[9] Univ Calif Berkeley, Dept Environm Sci Policy & Management, Berkeley, CA 94720 - USA
[10] Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA 94720 - USA
[11] Univ Sao Paulo, Dept Appl Phys, Sao Paulo - Brazil
[12] NOAA, Earth Syst Res Lab, Boulder, CO - USA
[13] Univ Oslo, Dept Chem, Oslo - Norway
[14] Univ Innsbruck, Inst Ion Phys & Appl Phys, A-6020 Innsbruck - Austria
[15] Univ Innsbruck, Inst Atmospher & Cryospher Sci, A-6020 Innsbruck - Austria
[16] Natl Ctr Atmospher Res, ACD, Boulder, CO 80307 - USA
[17] Alion Sci & Technol, Res Triangle Pk, NC - USA
[18] Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 - USA
[19] Univ Manchester, Sch Earth Atmospher & Environm Sci, Manchester, Lancs - England
[20] Univ Manchester, Natl Ctr Atmospher Sci, Manchester, Lancs - England
[21] Aerodyne Res Inc, Billerica, MA - USA
[22] NOAA, Geophys Fluid Dynam Lab, Princeton, NJ - USA
[23] Princeton Univ, Program Atmospher & Ocean Sci, Princeton, NJ 08544 - USA
Número total de Afiliações: 23
Tipo de documento: Artigo Científico
Fonte: Atmospheric Chemistry and Physics; v. 15, n. 20, p. 11807-11833, 2015.
Citações Web of Science: 92

Substantial amounts of secondary organic aerosol (SOA) can be formed from isoprene epoxydiols (IEPOX), which are oxidation products of isoprene mainly under low-NO conditions. Total IEPOX-SOA, which may include SOA formed from other parallel isoprene oxidation pathways, was quantified by applying positive matrix factorization (PMF) to aerosol mass spectrometer (AMS) measurements. The IEPOX-SOA fractions of organic aerosol (OA) in multiple field studies across several continents are summarized here and show consistent patterns with the concentration of gas-phase IEPOX simulated by the GEOS-Chem chemical transport model. During the Southern Oxidant and Aerosol Study (SOAS), 78% of PMF-resolved IEPOX-SOA is accounted by the measured IEPOX-SOA molecular tracers (2-methyltetrols, C5-Triols, and IEPOX-derived organosulfate and its dimers), making it the highest level of molecular identification of an ambient SOA component to our knowledge. An enhanced signal at C5H6O+ (m/z 82) is found in PMF-resolved IEPOX-SOA spectra. To investigate the suitability of this ion as a tracer for IEPOX-SOA, we examine fC(5)H(6)O (fC(5)H(6)O = C5H6O+ / OA) across multiple field, chamber, and source data sets. A background of similar to 1.7 +/- 0.1 parts per thousand (parts per thousand = parts per thousand) is observed in studies strongly influenced by urban, biomass-burning, and other anthropogenic primary organic aerosol (POA). Higher background values of 3.1 +/- 0.6 parts per thousand are found in studies strongly influenced by monoterpene emissions. The average laboratory monoterpene SOA value (5.5 +/- 2.0 parts per thousand) is 4 times lower than the average for IEPOX-SOA (22 +/- 7 parts per thousand), which leaves some room to separate both contributions to OA. Locations strongly influenced by isoprene emissions under low-NO levels had higher fC(5)H(6)O (similar to 6.5 +/- 2.2 parts per thousand on average) than other sites, consistent with the expected IEPOX- SOA formation in those studies. fC(5)H(6)O in IEPOX- SOA is always elevated (12-40 parts per thousand) but varies substantially between locations, which is shown to reflect large variations in its detailed molecular composition. The low fC(5)H(6)O (< 3 parts per thousand) reported in non-IEPOX-derived isoprene-SOA from chamber studies indicates that this tracer ion is specifically enhanced from IEPOX- SOA, and is not a tracer for all SOA from isoprene. We introduce a graphical diagnostic to study the presence and aging of IEPOX- SOA as a triangle plot of f(CO2) vs. fC(5)H(6)O. Finally, we develop a simplified method to estimate ambient IEPOX- SOA mass concentrations, which is shown to perform well compared to the full PMF method. The uncertainty of the tracer method is up to a factor of similar to 2, if the fC(5)H(6)O of the local IEPOX- SOA is not available. When only unit mass-resolution data are available, as with the aerosol chemical speciation monitor (ACSM), all methods may perform less well because of increased interferences from other ions at m/z 82. This study clarifies the strengths and limitations of the different AMS methods for detection of IEPOX- SOA and will enable improved characterization of this OA component. (AU)

Processo FAPESP: 14/05238-8 - Propriedades físico químicas de aerossóis orgânicos secundários biogênicos na Floresta Amazônica
Beneficiário:Samara Carbone
Linha de fomento: Bolsas no Brasil - Pós-Doutorado
Processo FAPESP: 13/05014-0 - GoAmazon: interação da pluma urbana de Manaus com emissões biogênicas da Floresta Amazônica
Beneficiário:Paulo Eduardo Artaxo Netto
Linha de fomento: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Temático