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| Titel |
Climatology of northern polar latitude MLT dynamics: mean winds and tides |
| VerfasserIn |
G. Kishore Kumar, W. K. Hocking |
| 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 ; 28, no. 10 ; Nr. 28, no. 10 (2010-10-07), S.1859-1876 |
| Datensatznummer |
250016895
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| Publikation (Nr.) |
 copernicus.org/angeo-28-1859-2010.pdf |
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| Zusammenfassung |
| Mean winds and tides in the northern polar Mesosphere and Lower Thermosphere
(MLT) have been studied using meteor radars located at Resolute Bay
(75° N, 95° W) and Yellowknife (62.5° N, 114.3° W). The
measurements for Resolute Bay span almost 12 years from July 1997 to February
2009 and the Yellowknife data cover 7 years from June 2002 to October 2008. The
analysis reveals similar wind flow over both sites with a difference in
magnitude. The summer zonal flow is westward at lower heights, eastward at
upper heights and the winter zonal flow is eastward at all heights. The
winter meridional flow is poleward and sometimes weakly equatorward, while
non winter months show equatorward flow, with a strong equatorward jet
during mid-summer months. The zonal and meridional winds show strong
interannual variation with a dominant annual variation as well as
significant latitudinal variation. Year to year variability in both zonal
and meridional winds exists, with a possible solar cycle dependence. The
diurnal, semidiurnal and terdiurnal tides also show large interannual
variability and latitudinal variation. The diurnal
amplitudes are dominated by an annual variation. The climatological monthly
mean winds are compared with CIRA 86, GEWM and HWM07 and the climatological
monthly mean amplitudes and phases of diurnal and semidiurnal tides are
compared with GSWM00 predictions. The GEWM shows better agreement with
observations than the CIRA 86 and HWM07. The GSWM00 model predictions need
to be modified above 90 km. The agreements and disagreements between
observations and models are discussed. |
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