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| Titel |
Statistical characteristics of gravity wave activities observed by an OH airglow imager at Xinglong, in northern China |
| VerfasserIn |
Q. Li, J. Xu, J. Yue, W. Yuan, X. Liu |
| 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 ; 29, no. 8 ; Nr. 29, no. 8 (2011-08-23), S.1401-1410 |
| Datensatznummer |
250017074
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| Publikation (Nr.) |
 copernicus.org/angeo-29-1401-2011.pdf |
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| Zusammenfassung |
| An all-sky airglow imager (ASAI) was installed at Xinglong, in northern
China (40.2° N, 117.4° E) in November 2009 to study the morphology
of atmospheric gravity waves (AGWs) in the mesosphere and lower thermosphere
(MLT) region. Using one year of OH airglow imager data from December 2009 to
November 2010, the characteristics of short-period AGWs are investigated and
a yearlong AGW climatology in northern China is first ever reported. AGW
occurrence frequency in summer and winter is higher than that in equinoctial
months. Observed bands mainly have horizontal wavelengths from 10 to 35 km,
observed periods from 4 to 14 min and observed horizontal phase speeds in
the range of 30 to 60 m s−1. Most of the bands propagate in the meridional
direction. The propagation directions of the bands show a strong
southwestward preference in winter, while almost all bands propagate
northeastward in summer. Although the wind filtering in the middle
atmosphere may control AGW propagations in the zonal direction, the
non-uniform distribution of wave sources in the lower atmosphere may
contribute to the anisotropy in the meridional direction in different
seasons. Additionally, as an indication of local instability, the
characteristics of ripples are also analyzed. It also shows seasonal
variations, occurring more often in summer and winter and mainly moving
westward in summer and eastward in winter. |
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