| Texto completo | |
| Autor(es): Mostrar menos - |
Hu, W. W.
[1, 2]
;
Campuzano-Jost, P.
[1, 2]
;
Palm, B. B.
[1, 2]
;
Day, D. A.
[1, 2]
;
Ortega, A. M.
[2, 3]
;
Hayes, P. L.
[1, 2]
;
Krechmer, J. E.
[1, 2]
;
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.
[12, 1]
;
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): Mostrar menos - | [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 |
| Resumo | |
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: | 13/05014-0 - GoAmazon: interação da pluma urbana de Manaus com emissões biogênicas da Floresta Amazônica |
| Beneficiário: | Paulo Eduardo Artaxo Netto |
| Modalidade de apoio: | Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Temático |
| Processo FAPESP: | 14/05238-8 - Propriedades físico químicas de aerossóis orgânicos secundários biogênicos na Floresta Amazônica |
| Beneficiário: | Samara Carbone |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |