The influence of time-dependent wind on gravity-wave propagation in the middle atmosphere
Ray-tracing techniques are used to computationally investigate the propagation of gravity waves through the middle atmosphere, as characterized by the vertically varying CIRA-86 wind and temperature models, plus a tidal wind model that varies temporally as well as vertically. For the wave parameters...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
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| Series: | Annales Geophysicae |
| Online Access: | http://www.ann-geophys.net/13/375/1995/angeo-13-375-1995.html |
| _version_ | 1811245669595217920 |
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| author | L. Zhong L. J. Sonmor A. H. Manson C. E. Meek |
| author_facet | L. Zhong L. J. Sonmor A. H. Manson C. E. Meek |
| author_sort | L. Zhong |
| collection | DOAJ |
| description | Ray-tracing techniques are used to computationally investigate the propagation of gravity waves through the middle atmosphere, as characterized by the vertically varying CIRA-86 wind and temperature models, plus a tidal wind model that varies temporally as well as vertically. For the wave parameters studied here, the background wind variation has a much stronger influence on the ray path and changes in wave characteristics than does the temperature variation. The temporal variation of the tidal component of the wind changes the observed frequency, sometimes substantially, while leaving the intrinsic frequency unaltered. It also renders temporary any critical levels that occur in the tidal region. Different starting times for the rays relative to the tidal phase provide different propagation environments, so that the temporary critical levels appear at different heights. The lateral component of the tidal wind is shown to advect propagating wave packets; the maximum lateral displacement of a packet varies inversely with its vertical group velocity. Time-dependent effects are more pronounced in local winter than in summer. |
| first_indexed | 2024-04-12T14:42:50Z |
| format | Article |
| id | doaj.art-b26770209b2346a4bf8234ec166041b9 |
| institution | Directory Open Access Journal |
| issn | 0992-7689 1432-0576 |
| language | English |
| last_indexed | 2024-04-12T14:42:50Z |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Annales Geophysicae |
| spelling | doaj.art-b26770209b2346a4bf8234ec166041b92022-12-22T03:28:46ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-0576134375394The influence of time-dependent wind on gravity-wave propagation in the middle atmosphereL. ZhongL. J. SonmorA. H. MansonC. E. MeekRay-tracing techniques are used to computationally investigate the propagation of gravity waves through the middle atmosphere, as characterized by the vertically varying CIRA-86 wind and temperature models, plus a tidal wind model that varies temporally as well as vertically. For the wave parameters studied here, the background wind variation has a much stronger influence on the ray path and changes in wave characteristics than does the temperature variation. The temporal variation of the tidal component of the wind changes the observed frequency, sometimes substantially, while leaving the intrinsic frequency unaltered. It also renders temporary any critical levels that occur in the tidal region. Different starting times for the rays relative to the tidal phase provide different propagation environments, so that the temporary critical levels appear at different heights. The lateral component of the tidal wind is shown to advect propagating wave packets; the maximum lateral displacement of a packet varies inversely with its vertical group velocity. Time-dependent effects are more pronounced in local winter than in summer.http://www.ann-geophys.net/13/375/1995/angeo-13-375-1995.html |
| spellingShingle | L. Zhong L. J. Sonmor A. H. Manson C. E. Meek The influence of time-dependent wind on gravity-wave propagation in the middle atmosphere Annales Geophysicae |
| title | The influence of time-dependent wind on gravity-wave propagation in the middle atmosphere |
| title_full | The influence of time-dependent wind on gravity-wave propagation in the middle atmosphere |
| title_fullStr | The influence of time-dependent wind on gravity-wave propagation in the middle atmosphere |
| title_full_unstemmed | The influence of time-dependent wind on gravity-wave propagation in the middle atmosphere |
| title_short | The influence of time-dependent wind on gravity-wave propagation in the middle atmosphere |
| title_sort | influence of time dependent wind on gravity wave propagation in the middle atmosphere |
| url | http://www.ann-geophys.net/13/375/1995/angeo-13-375-1995.html |
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