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| Titel |
Simultaneous lidar observations of temperatures and waves in the polar middle atmosphere on the east and west side of the Scandinavian mountains: a case study on 19/20 January 2003 |
| VerfasserIn |
U. Blum, K. H. Fricke, G. Baumgarten, A. Schöch |
| 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 ; 4, no. 3 ; Nr. 4, no. 3 (2004-06-03), S.809-816 |
| Datensatznummer |
250001719
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| Publikation (Nr.) |
 copernicus.org/acp-4-809-2004.pdf |
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| Zusammenfassung |
| Atmospheric gravity waves have been the subject of intense
research for several decades because of their extensive effects on
the atmospheric circulation and the temperature structure. The
U. Bonn lidar at the Esrange and the ALOMAR RMR lidar at the Andøya
Rocket Range are located in northern Scandinavia 250 km apart on
the east and west side of the Scandinavian mountain ridge. During
January and February 2003 both lidar systems conducted
measurements and retrieved atmospheric temperatures. On
19/20 January 2003 simultaneous measurements for more than
7 h were possible. Although during most of the campaign time the
atmosphere was not transparent for the propagation of
orographically induced gravity waves, they were nevertheless
observed at both lidar stations with considerable amplitudes
during these simultaneous measurements. And while the source of
the observed waves cannot be determined unambiguously, the
observations show many characteristics of orographically excited
gravity waves. The wave patterns at ALOMAR show a random
distribution with time whereas at the Esrange a persistency in the
wave patterns is observable. This persistency can also be found in
the distribution of the most powerful vertical wavelengths. The
mode values are both at about 5 km vertical wavelength,
however the distributions are quite different, narrow at the
Esrange with values from λz=2–6 km and broad at
ALOMAR, covering λz=1–12 km vertical wavelength.
In particular the difference between the observations at ALOMAR
and at the Esrange can be understood by different orographic
conditions while the propagation conditions were quite similar. At
both stations the waves deposit energy in the atmosphere with
increasing altitude, which leads to a decrease of the observed
gravity wave potential energy density with altitude. The
meteorological situation during these measurements was different
from common winter situations. The ground winds were mostly
northerlies, changed in the upper troposphere and lower
stratosphere to westerlies and returned to northerlies in the
middle stratosphere. |
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