 |
| Titel |
Climatological monthly characteristics of middle atmosphere gravity waves (10 min-10 h) during 1979-1993 at Saskatoon |
| VerfasserIn |
N. M. Gavrilov, A. H. Manson, C. E. Meek |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
0992-7689
|
| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 13, no. 3 ; Nr. 13, no. 3, S.285-295 |
| Datensatznummer |
250011788
|
| Publikation (Nr.) |
 copernicus.org/angeo-13-285-1995.pdf |
|
|
|
|
|
| Zusammenfassung |
| Saskatoon (52° N, 107°W) medium frequency
(MF) radar data from 1979 to 1993 have been analyzed to investigate the
climatology of irregular wind components in the height region 60-100 km. This
component is usually treated in terms of internal gravity waves (IGW). Three
different band-pass filters have been used to separate the intensities of IGWs
having periods 0.2-2.5; 1.5-6 and 2-10 h, respectively. Height, seasonal and
inter-annual variations of IGW intensities, anisotropy and predominant
directions of propagation are investigated. Mean over 14 years' seasonal
variation of the intensity of long-period IGWs shows a dominant annual component
with winter maximum and summer minimum. Seasonal variations of the intensity of
short-period waves have a strong semi-annual component as well, which forms a
secondary maximum in summer. Predominant azimuths of long-period IGWs are
generally zonal, though they vary with season. For short-period IGWs, the
predominant azimuth is closer to the meridional direction. Anisotropy of IGW
intensity is larger in summer, winter and at lower altitudes. The IGW intensity
shows apparent correlation with both solar and geomagnetic activity. In most
cases, this correlation appears to be negative. The variations versus solar
activity is larger for longer-period IGW. Possible reasons and consequences of
the observed climatological variations of IGW intensity are discussed. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|