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| Titel |
Multi-year observations of gravity wave momentum fluxes at low and middle latitudes inferred by all-sky meteor radar |
| VerfasserIn |
V. F. Andrioli, P. P. Batista, B. R. Clemesha, N. J. Schuch, R. A. Buriti |
| 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 ; 33, no. 9 ; Nr. 33, no. 9 (2015-09-30), S.1183-1193 |
| Datensatznummer |
250121250
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| Publikation (Nr.) |
 copernicus.org/angeo-33-1183-2015.pdf |
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| Zusammenfassung |
| We have applied a modified composite day analysis to the Hocking (2005)
technique to study gravity wave (GW) momentum fluxes in the mesosphere and
lower thermosphere (MLT). Wind measurements from almost continuous meteor
radar observations during June 2004–December 2008 over São João
do Cariri (Cariri; 7° S, 36° W), April 1999–November
2008 over Cachoeira Paulista (CP; 23° S, 45° W), and
February 2005–December 2009 over Santa Maria (SM; 30° S,
54° W) were used to estimate the GW momentum fluxes and variances
in the MLT region. Our analysis can provide monthly mean altitude profiles
of vertical fluxes of horizontal momentum for short-period (less than 2–3 h) GWs. The averages for each month throughout the entire data series have
shown different behavior for the momentum fluxes depending on latitude and
component. The meridional component has almost the same behavior at the
three sites, being positive (northward), for most part of the year. On the
other hand, the zonal component shows different behavior at each location:
it is positive for almost half the year at Cariri and SM but predominantly
negative over CP. Annual variation in the GW momentum fluxes is present at
all sites in the zonal component and also in SM at 89 km in the meridional
component. The seasonal analysis has also shown a 4-month oscillation at
92.5 km over SM in the zonal component and over CP at the same altitudes but
for the meridional component. |
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