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| Titel |
Chemical characterization of submicron regional background aerosols in the western Mediterranean using an Aerosol Chemical Speciation Monitor |
| VerfasserIn |
M. C. Minguillón, A. Ripoll, N. Pérez, A. S. H. Prévôt, F. Canonaco, X. Querol, A. Alastuey |
| 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 ; 15, no. 11 ; Nr. 15, no. 11 (2015-06-11), S.6379-6391 |
| Datensatznummer |
250119804
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| Publikation (Nr.) |
 copernicus.org/acp-15-6379-2015.pdf |
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| Zusammenfassung |
| An Aerosol Chemical Speciation Monitor (ACSM, Aerodyne Research Inc.) was deployed at
the Montseny (MSY; 41° 46'46" N, 02° 21'29" E,
720 m a.s.l.) regional background site in the western
Mediterranean, Spain, from June 2012 to
July 2013 to measure real-time inorganic (nitrate, sulfate, ammonium and
chloride) and organic submicron aerosol concentrations. Co-located
measurements, including real-time submicron particulate matter (PM1) and
black carbon (BC) concentrations, and off-line PM1 chemical analysis
were also carried out. This is one of the few studies that compare ACSM data
with off-line PM1 measurements, avoiding the tail of the coarse mode
included in the PM2.5 fraction. The ACSM + BC concentrations agreed
with the PM1 measurements, and a strong correlation was found between
the concentrations of ACSM species and the off-line measurements, although
some discrepancies remain unexplained. Results point to a current
underestimation of the relative ionization efficiency (RIE) established for
organic aerosol (OA), which should be revised in the future. The OA was the
major component of submicron aerosol (53% of PM1), with a higher
contribution in summer (58% of PM1) than in winter (45% of
PM1). Source apportionment of OA was carried out by applying positive
matrix factorization (PMF), using the multilinear engine (ME-2) to the
organic mass spectral data matrix. Three sources were identified in summer:
hydrocarbon-like OA (HOA), low-volatile oxygenated OA (LV-OOA), and
semi-volatile oxygenated OA (SV-OOA). The secondary OA (SOA;
4.8 μg m−3, sum of LV-OOA and SV-OOA) accounted for 85% of
the total OA, and its formation during daytime (mainly SV-OOA) was estimated
to be 1.1 μg m−3. In winter, HOA was also identified (12%
of OA), a contribution from biomass burning OA (BBOA) was included and it was not
possible to differentiate between two different SOA factors, but a single
oxygenated OA (OOA)
factor was resolved. The OOA contribution represented 60% of the total OA,
with a degree of oxidation higher than both OOA summer factors. An intense
wildfire episode was studied, obtaining a region-specific BBOA profile. |
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