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| Titel |
Mountain wave motions determined by the Esrange MST radar |
| VerfasserIn |
A. Réchou, V. Barabash, P. Chilson, S. Kirkwood  , T. Savitskaya, K. Stebel |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
0992-7689
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| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 17, no. 7 ; Nr. 17, no. 7, S.957-970 |
| Datensatznummer |
250013792
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| Publikation (Nr.) |
 copernicus.org/angeo-17-957-1999.pdf |
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| Zusammenfassung |
A European campaign of ground-based radar,
lidar and optical measurements was carried out during the winter of 1996/1997
(28 December-2 February) to study lee waves in the northern part of Scandinavia.
The participants operated ozone lidars, backscatter lidars and MST radars at
ALOMAR/Andoya and Esrange/Kiruna, and an ALIS imaging system in Kiruna. The
Andoya site was generally windward of the Scandinavian mountains, the Kiruna
site on the leeward side. The goal of the experiment was to examine the
influence of lee waves on the formation of Polar Stratospheric Clouds (PSCs).
This paper studies the radar data from MST-radar ESRAD located at Esrange [68.°N,
21.°E], i.e. in the lee of the mountains. We present three cases
where strong lee waves were observed: in one case they propagated upwards to the
lower stratosphere and in the other two cases they were trapped or absorbed in
the troposphere. We examine the local waves and the direction and strength of
the local wind using the radar, the synoptic meteorological situation using
weather maps (European Meteorological Bulletin) and the synoptic stratospheric
temperatures using ECMWF data. We observed that waves propagate up to the
stratosphere during frontal passages. When anticyclonic ridges are present, the
propagation to the stratosphere is very weak. This is due to trapping of the
waves at or below the tropopause. We also show that the radar data alone can be
used to characterise the different weather conditions for the three cases
studied (through the variation of the height of the tropopause). The synoptic
stratospheric temperatures in the three cases were similar, and were above the
expected threshold for PSC formation. Lidar and visual observation of PSCs and
nacreous clouds, respectively, showed that these were present only in the case
when the lee waves propagated up to the lower stratosphere.
Key words. Atmospheric composition and structure
(aerosols and particles) · Electromagnetic (wave propa- gation) · Meteorology
and atmospheric dynamics (mesoscale meteorology) |
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