Journal cover Journal topic
Annales Geophysicae An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 1.585 IF 1.585
  • IF 5-year value: 1.698 IF 5-year
    1.698
  • CiteScore value: 1.62 CiteScore
    1.62
  • SNIP value: 0.820 SNIP 0.820
  • IPP value: 1.52 IPP 1.52
  • SJR value: 0.781 SJR 0.781
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 83 Scimago H
    index 83
  • h5-index value: 24 h5-index 24
Volume 27, issue 3
Ann. Geophys., 27, 1059–1065, 2009
https://doi.org/10.5194/angeo-27-1059-2009
© Author(s) 2009. This work is distributed under
the Creative Commons Attribution 3.0 License.

Special issue: 12th International Symposium on Equatorial Aeronomy...

Ann. Geophys., 27, 1059–1065, 2009
https://doi.org/10.5194/angeo-27-1059-2009
© Author(s) 2009. This work is distributed under
the Creative Commons Attribution 3.0 License.

  04 Mar 2009

04 Mar 2009

Seasonal variations in gravity wave activity at three locations in Brazil

B. R. Clemesha1, P. P. Batista1, R. A. Buriti da Costa2, and N. Schuch3 B. R. Clemesha et al.
  • 1Instituto Nacional de Pesquisas Espaciais, São José dos Campos, SP, Brazil
  • 2Universidade Federal de Campina Grande, Campina Grande, PB, Brazil
  • 3Centro Regional Sul de Pesquisas Espaciais – INPE, Santa Maria, RS, Brazil

Abstract. Using the variance in meteor radar winds as a measure of gravity wave activity, we investigate the temporal variations in gravity waves at three locations in Brazil: São João do Cariri (7.3° S, 36.4° W), Cachoeira Paulista (22.7° S, 45.0° W) and Santa Maria (29.7° S, 53.7° W). The technique used is that of Hocking (2005) which makes it possible to separate the zonal and meridional components of the fluctuating wind velocity. We find that the seasonal variation of the fluctuating wind is similar to that of the amplitude of the diurnal tide, showing a predominantly semi-annual variation, stronger at Cachoeira Paulista and Santa Maria than at the quasi-equatorial station, Cariri. Both with respect to the seasonal trend and shorter term variations, strong coupling between gravity wave activity and tides is indicated by a remarkably close correlation between the fluctuating velocity and the vertical shear in the tidal winds. It is not clear as to whether this is caused by gravity wave forcing of the tides or whether it results from in situ generation of gravity waves by tidal wind shear.

Publications Copernicus
Download
Citation