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Titel |
The regime of intense desert dust episodes in the Mediterranean based on contemporary satellite observations and ground measurements |
VerfasserIn |
A. Gkikas, N. Hatzianastassiou, N. Mihalopoulos, V. Katsoulis, S. Kazadzis, J. Pey, X. Querol, O. Torres |
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 ; 13, no. 23 ; Nr. 13, no. 23 (2013-12-13), S.12135-12154 |
Datensatznummer |
250085880
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Publikation (Nr.) |
copernicus.org/acp-13-12135-2013.pdf |
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Zusammenfassung |
The regime of intense desert dust (DD) episodes over the broader
Mediterranean Basin is studied for the period 2000–2007 at a complete
spatial coverage. An objective and dynamic algorithm has been set up which
uses daily measurements of various aerosol optical properties taken by
different satellite databases, enabling the identification of DD episodes
and their classification into strong and extreme ones. The algorithm's
performance was tested against surface-based (in situ) particulate matter
(PM) and (columnar) sun-photometric AERONET (AErosol RObotic NETwork) measurements from stations
distributed across the Mediterranean. The comparisons have shown the
reasonable ability of the algorithm to detect the DD episodes taking place
within the study region. The largest disagreements with PM data were found
in the western Mediterranean in summer, when African dust transport has a great
vertical extent that cannot be satisfactorily captured by surface
measurements.
According to our results, DD episodes in the Mediterranean Basin are quite
frequent (up to 11.4 episodes yr−1), while there is a significant spatial and
temporal variability in their frequency of occurrence and their intensity.
Strong episodes occur more frequently in the western Mediterranean Basin,
whilst extreme ones appear more frequently over central Mediterranean Sea
areas. Apart from this longitudinal variation, there is a predominant
latitudinal variability in both frequency and intensity, with decreasing
values from south to north. A significant seasonal variation was also found
for the frequency of DD episodes, with both strong and extreme episodes
being more frequent during summer in the western Mediterranean Basin, but
during spring in its central and eastern parts. In most cases (> 85%)
the Mediterranean dust episodes last a bit longer than a day on
average, although their duration can reach six~days for strong episodes and four~days
for extreme episodes. A noticeable year-to-year variability was also
found, especially for the frequency of the episodes. |
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