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Titel |
Fog characteristics at the airport of Thessaloniki, Greece |
VerfasserIn |
S. N. Stolaki, S. A. Kazadzis, D. V. Foris, Th. S. Karacostas |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1561-8633
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Digitales Dokument |
URL |
Erschienen |
In: Natural Hazards and Earth System Science ; 9, no. 5 ; Nr. 9, no. 5 (2009-09-03), S.1541-1549 |
Datensatznummer |
250006976
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Publikation (Nr.) |
copernicus.org/nhess-9-1541-2009.pdf |
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Zusammenfassung |
A statistical approach in order to study fog event characteristics occuring
at the airport of Thessaloniki, Northern Greece is presented in this work.
To achieve this, the seasonal and diurnal characteristics of fog are
investigated using 35 years (1971–2005) of observations of meteorological
parameters such as: visibility, air temperature, dew point temperature, air
relative humidity, wind vector, precipitation, and cloud base height and
coverage. Hourly surface observations of fifteen (15) years (1991–2005) are
used to identify fog events induced by various physical mechanisms. Fog
events are classified into fog types through the application of objective
criteria that are derived upon fog formation processes and under the
influence of various physiographic features. The temporal variability of
different fog type occurrences are examined and the events are characterized
according to their duration and intensity.
The results are somehow affected by regional and local factors. Fog is
mainly formed in winter time (~64%) with an enhanced likelihood to
appear also in late autumn (19%). The highest frequency of the fog events
occurs around sunrise or 1 to 2 h before of it. The mean duration of the
events is about 4.5 h. Most of them (75%) are dense (visibility <400 m). The overall fog phenomenon is a combination of various types, such
as: advection fog, radiation fog, cloud-base lowering fog and precipitation
fog. Advection fog (30%) and radiation fog (29%), which are the most
common types, occur predominantly in winter and early spring time. With
respect to the former type, it seems that, in many cases, already formed fog
is advected from the nearby Anthemountas valley. Moreover, a considerable number of fog
events (22%) result from cloud-base lowering, and they frequently occur
in late autumn and mid winter. |
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