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| Titel |
Joint analysis of continental and regional background environments in the western Mediterranean: PM1 and PM10 concentrations and composition |
| VerfasserIn |
A. Ripoll, M. C. Minguillón, J. Pey, N. Pérez, 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. 2 ; Nr. 15, no. 2 (2015-01-30), S.1129-1145 |
| Datensatznummer |
250119357
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| Publikation (Nr.) |
 copernicus.org/acp-15-1129-2015.pdf |
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| Zusammenfassung |
The complete chemical composition of atmospheric particulate
matter (PM1 and PM10) from a continental (Montsec, MSC, 1570 m a.s.l.)
and a regional (Montseny, MSY, 720 m a.s.l) background site in the
western Mediterranean Basin (WMB) were jointly studied for the first time
over a relatively long-term period (January 2010–March 2013).
Differences in average PMX concentration and composition between both
sites were attributed to distance to anthropogenic sources, altitude, and
different influence of atmospheric episodes. All these factors result in a
continental-to-regional background increase of 4.0 μg m−3 for
PM10 and 1.1 μg m−3 for PM1 in the WMB. This
increase is mainly constituted by organic matter, sulfate, nitrate, and sea
salt. However, higher mineral matter concentrations were measured at the
continental background site owing to the higher influence of long-range
transport of dust and dust resuspension.
Seasonal variations of aerosol chemical components were attributed to
evolution of the planetary boundary layer (PBL) height throughout the year,
variations in the air mass origin, and differences in meteorology. During
warmer months, weak pressure gradients and elevated insolation generate
recirculation of air masses and enhance the development of the PBL, causing
the aging of aerosols and incrementing pollutant concentrations over a large
area in the WMB, including the continental background. This is reflected in
a more similar relative composition and absolute concentrations of
continental and regional background aerosols. Nevertheless, during colder
months the thermal inversions and the lower vertical development of the PBL
leave MSC in the free troposphere most of the time, whereas MSY is more
influenced by regional pollutants accumulated under winter anticyclonic
conditions. This results in much lower concentrations of PMX components
at the continental background site with respect to those at the regional
background site.
The influence of certain atmospheric episodes caused different impacts at
regional and continental scales. When long-range transport from central and
eastern Europe and from north Africa occurs, the continental background site
is frequently more influenced, thus indicating a preferential transport of
pollutants at high altitude layers. Conversely, the regional background site
was more influenced by regional processes.
Continental and regional aerosol chemical composition from the WMB revealed
(a) high relevance of African dust transport and regional dust resuspension;
(b) low biomass burning contribution; (c) high organic matter contribution; (d)
low summer nitrate concentrations; and (e) high aerosol homogenization in
summer. |
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