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| Titel |
Mexico City aerosol analysis during MILAGRO using high resolution aerosol mass spectrometry at the urban supersite (T0) – Part 1: Fine particle composition and organic source apportionment |
| VerfasserIn |
A. C. Aiken, D. Salcedo, M. J. Cubison, J. A. Huffman, P. F. DeCarlo, I. M. Ulbrich, K. S. Docherty, D. Sueper, J. R. Kimmel, D. R. Worsnop, A. Trimborn, M. Northway, E. A. Stone, J. J. Schauer, R. M. Volkamer, E. Fortner, B. Foy, J. Wang, A. Laskin, V. Shutthanandan, J. Zheng, R. Zhang, J. Gaffney, N. A. Marley, G. Paredes-Miranda, W. P. Arnott, L. T. Molina, G. Sosa, J. L. Jimenez |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 9, no. 17 ; Nr. 9, no. 17 (2009-09-11), S.6633-6653 |
| Datensatznummer |
250007623
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| Publikation (Nr.) |
 copernicus.org/acp-9-6633-2009.pdf |
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| Zusammenfassung |
| Submicron aerosol was analyzed during the MILAGRO field campaign in March
2006 at the T0 urban supersite in Mexico City with a High-Resolution
Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and complementary
instrumentation. Mass concentrations, diurnal cycles, and size distributions
of inorganic and organic species are similar to results from the CENICA
supersite in April 2003 with organic aerosol (OA) comprising about half of
the fine PM mass. Positive Matrix Factorization (PMF) analysis of the high
resolution OA spectra identified three major components: chemically-reduced
urban primary emissions (hydrocarbon-like OA, HOA), oxygenated OA (OOA,
mostly secondary OA or SOA), and biomass burning OA (BBOA) that correlates
with levoglucosan and acetonitrile. BBOA includes several very large plumes
from regional fires and likely also some refuse burning. A fourth OA
component is a small local nitrogen-containing reduced OA component (LOA)
which accounts for 9% of the OA mass but one third of the organic nitrogen,
likely as amines. OOA accounts for almost half of the OA on average,
consistent with previous observations. OA apportionment results from PMF-AMS
are compared to the PM2.5 chemical mass balance of organic molecular
markers (CMB-OMM, from GC/MS analysis of filters). Results from both methods
are overall consistent. Both assign the major components of OA to primary
urban, biomass burning/woodsmoke, and secondary sources at similar
magnitudes. The 2006 Mexico City emissions inventory underestimates the urban
primary PM2.5 emissions by a factor of ~4, and it is
~16 times lower than afternoon concentrations when secondary species
are included. Additionally, the forest fire contribution is at least an
order-of-magnitude larger than in the inventory. |
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