 |
| Titel |
Chemical characterization of springtime submicrometer aerosol in Po Valley, Italy |
| VerfasserIn |
S. Saarikoski, S. Carbone, S. Decesari, L. Giulianelli, F. Angelini, M. Canagaratna, N. L. Ng, A. Trimborn, M. C. Facchini, S. Fuzzi, R. Hillamo, D. Worsnop |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 12, no. 18 ; Nr. 12, no. 18 (2012-09-19), S.8401-8421 |
| Datensatznummer |
250011454
|
| Publikation (Nr.) |
 copernicus.org/acp-12-8401-2012.pdf |
|
|
|
|
|
| Zusammenfassung |
| The chemistry of submicron particles was investigated at San Pietro
Capofiume (SPC) measurement station in the Po Valley, Italy, in spring 2008.
The measurements were performed by using both off-line and on-line
instruments. Organic carbon (OC) and elemental carbon, organic acids and
biomass burning tracers were measured off-line by using a 24-h PM1
filter sampling. More detailed particle chemistry was achieved by using a
Aerodyne high resolution time-of-flight aerosol mass spectrometer
(HR-ToF-AMS) and analyzing the data by positive matrix factorization (PMF).
Oxalic acid had the highest concentrations of organic acids
(campaign-average 97.4 ng m−3) followed by methane sulfonic, formic,
malonic, and malic acids. Samples were also analyzed for glyoxylic,
succinic, azelaic and maleic acids. In total, the nine acids composed 1.9
and 3.8% of OC and water-soluble OC, respectively (average), in terms of
carbon atoms. Levoglucosan concentration varied from 17.7 to 495 ng m−3
with the concentration decreasing in the course of the campaign most likely
due to the reduced use of domestic heating with wood. Six factors were found
for organic aerosol (OA) at SPC by PMF: hydrocarbon-like OA (HOA), biomass
burning OA (BBOA), nitrogen-containing OA (N-OA) and three different
oxygenated OAs (OOA-a, OOA-b and OOA-c). Most of the OA mass was composed of
OOA-a, HOA and OOA-c (26, 24 and 22%, respectively) followed by OOA-b
(13%), BBOA (8%) and N-OA (7%). As expected, OOAs were the most
oxygenated factors with organic matter:organic carbon (OM : OC) ratios ranging
from 1.9 to 2.2. The diurnal variability of the aerosol chemical composition
was greatly affected by the boundary layer meteorology. Specifically, the
effect of the nocturnal layer break-up in morning hours was most evident for
nitrate and N-OA indicating that these compounds originated mainly from the
local sources in the Po Valley. For sulfate and OOA-a the concentration did
not change during the break-up suggesting their origin to be mostly
regional. That resulted in much more oxidized OA in the daytime mixing layer
than in the nocturnal surface layer. In this study, the high mass resolution
and source-related aerosol chemistry from the HR-ToF-AMS was combined with
the filter measurements in a total new extent elucidating novel features and
sources of organic aerosol in the Po Valley region. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|