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| Titel |
Seasonal changes in gravity wave activity measured by lidars at mid-latitudes |
| VerfasserIn |
M. Rauthe, M. Gerding, F.-J. Lübken |
| 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 ; 8, no. 22 ; Nr. 8, no. 22 (2008-11-25), S.6775-6787 |
| Datensatznummer |
250006464
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| Publikation (Nr.) |
 copernicus.org/acp-8-6775-2008.pdf |
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| Zusammenfassung |
| More than 230 nights of temperature measurements between 1 and 105 km have been
performed at the Leibniz-Institute of Atmospheric Physics in Kühlungsborn with
a combination of two different lidars, i.e. a Rayleigh-Mie-Raman lidar and a
potassium lidar. About 1700 h of measurements have been collected between
2002 and 2006. Apart from some gaps due to the adverse weather conditions the
measurements are well distributed throughout the year. Comprehensive information
about the activity of medium- and low-frequency gravity waves was extracted
from this data set. The dominating vertical wavelengths found are between 10
and 20 km and do not show any seasonal variation. In contrast the temperature
fluctuations due to gravity waves experience a clear annual cycle with a
maximum in winter. The most significant differences exist around 60 km
where the fluctuations in winter are more than two times larger than they
are in summer. Only small seasonal differences are observed above 90 km
and below 35 km. Generally, the fluctuations grow from about 0.5 K up
to 8 K between 20 and 100 km. Damping of waves is observed at nearly all
altitudes and in all seasons. The planetary wave activity shows a similar
structure in altitude and season as the gravity wave activity which indicates
that similar mechanisms influencing different scales. Combining the monthly
mean temperatures and the fluctuations we show that the transition between
winter and summer season and vice versa seems to start in the mesopause
region and to penetrate downward. |
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