|
Titel |
Aerosol chemistry above an extended archipelago of the eastern Mediterranean basin during strong northern winds |
VerfasserIn |
E. Athanasopoulou, A. P. Protonotariou, E. Bossioli, A. Dandou, M. Tombrou, J. D. Allan, H. Coe, N. Mihalopoulos, J. Kalogiros, A. Bacak, J. Sciare, G. Biskos |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
1680-7316
|
Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 14 ; Nr. 15, no. 14 (2015-07-28), S.8401-8421 |
Datensatznummer |
250119933
|
Publikation (Nr.) |
copernicus.org/acp-15-8401-2015.pdf |
|
|
|
Zusammenfassung |
Detailed aerosol chemical predictions by a comprehensive model system (i.e.
PMCAMx, WRF, GEOS-CHEM), along with airborne and ground-based observations,
are presented and analysed over a wide domain covering the Aegean
Archipelago. The studied period is 10 successive days in 2011,
characterized by strong northern winds, which is the most frequently
prevailing synoptic pattern during summer. The submicron aerosol load in the
lower troposphere above the archipelago is homogenously enriched in sulfate
(average modelled and measured submicron sulfate of 5.5 and 5.8 μg m−3, respectively), followed by organics (2.3 and 4.4 μg m−3)
and ammonium (1.5 and 1.7 μg m−3). Aerosol concentrations smoothly
decline aloft, reaching lower values (< 1 μg m−3) above
4.2 km altitude. The evaluation criteria rate the model results for sulfate,
ammonium, chloride, elemental carbon, organic carbon and total PM10
mass concentrations as "good", indicating a satisfactory representation of
the aerosol chemistry and precursors. Higher model discrepancies are
confined to the highest (e.g. peak sulfate values) and lowest ends (e.g.
nitrate) of the airborne aerosol mass size distribution, as well as in
airborne organic aerosol concentrations (model underestimation ca. 50 %).
The latter is most likely related to the intense fire activity at the
eastern Balkan area and the Black Sea coastline, which is not represented in
the current model application. The investigation of the effect of local
variables on model performance revealed that the best agreement between
predictions and observations occurs during high winds from the northeast, as
well as for the area confined above the archipelago and up to 2.2 km
altitude. The atmospheric ageing of biogenic particles is suggested to be
activated in the aerosol chemistry module, when treating organics in a
sufficient nitrogen and sulfate-rich environment, such as that over the
Aegean basin. More than 70 % of the predicted aerosol mass over the Aegean
Archipelago during a representative Etesian episode is related to transport
of aerosols and their precursors from outside the modelling domain. |
|
|
Teil von |
|
|
|
|
|
|