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| Titel |
New insights on aerosol sources and properties of Organics in the west Mediterranean basin |
| VerfasserIn |
José B. Nicolas, Jean Sciare, Jean-Eudes Petit, Nicolas Bonnaire, Anaïs Féron, François Dulac, Eric Hamonou, Valérie Gros, Marc Mallet, Dominique Lambert, Stéphane Sauvage, Thierry Leonardis, Emmanuel Tison, Aurelie Colomb, Evelyn Fresney, Jean-Marc Pichon, Laetitia Bouvier, Thierry Bourrianne, Gregory Roberts |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250083741
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| Zusammenfassung |
| The Mediterranean basin exhibits high PM concentrations for a marine area, in particular
during the dry season (summer), associated with high photochemistry. The large population
of the basin is impacted by both natural and anthropogenic aerosols of various sources from
Europe and North Africa. Simulations predict significant climate changes in that area, with
less precipitation and hotter temperatures, reinforced by an increasing anthropogenic
pressure, which will be linked by higher emissions of pollutants and also by higher impacts
on the health. Nevertheless the aerosol models in that area currently suffer from
large uncertainties, due to a lack of knowledge in organic aerosol (OA) sources and
processes.
As part of the French program ChArMEx (The Chemistry-Aerosol Mediterranean
Experiment, http://charmex.lsce.ipsl.fr), a 5-week intensive campaign has been
performed in June - July 2012 at the new Cape Corsica station (see Dulac et al.
in that session), and aiming at a better characterization of anthropogenic versus
biogenic aerosols, long range transport versus local influence, with a focus on fine
OA.
A complete instrumental strategy was deployed thanks to the contribution of a large
French community: PM1 concentration every 6 min with a TEOM-FDMS 1405 (Thermo),
major aerosol components in PM1 every 30 min (Organics, SO4, NO3, NH4) by Aerosol
Chemical Speciation Monitor (Aerodyne), Equivalent Black Carbon every 5 min with a 7-λ
aethalometer AE31 (Magee Scientific), on-line major anions and cations (incl. light organics
like oxalate & MSA) every 10 min with Particle-Into-Liquid Sampler (PILS, Metrohm)
coupled with Ion Chromatographs (Dionex), on-line water-soluble organic carbon (WSOC)
every 4 min with a PILS (Applikon) coupled with a Total Organic Carbon instrument
(Ionics). Filter sampling in PM2.5 and PM10 was also performed every 12h for quality
purposes (PM, EC/OC, ions) and for complementary measurements (metals by ICP-MS and
organic tracers by LC-MS). Additional measurements of reactive gases (CO, O3 and VOCs),
and of aerosol optical/physical properties (scattering, extinction, size distribution)
were used for a better identification of air masses origin and optical/number closure
studies.
Backtrajectories issued from Hysplit 4.9 revealed the predominance of air masses from
North-West to South, with some dust events from North Africa (Morocco, Algeria) and a few
anthropogenic events from Italy and from South-East of France. Two intense heat waves,
associated with low wind speed, gave the highest levels of OA observed during the campaign,
suggesting a possible local biogenic origin. The comparison of these heat waves showed
contrasted levels of WSOC, oxalate, OM-to-OC ratio suggesting various sources and/or
processes. |
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