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 24, issue 12
Ann. Geophys., 24, 3343–3350, 2006
https://doi.org/10.5194/angeo-24-3343-2006
© Author(s) 2006. This work is distributed under
the Creative Commons Attribution 3.0 License.
Ann. Geophys., 24, 3343–3350, 2006
https://doi.org/10.5194/angeo-24-3343-2006
© Author(s) 2006. This work is distributed under
the Creative Commons Attribution 3.0 License.

  21 Dec 2006

21 Dec 2006

Signatures of 3–6 day planetary waves in the equatorial mesosphere and ionosphere

H. Takahashi1, C. M. Wrasse1, D. Pancheva2, M. A. Abdu1, I. S. Batista1, L. M. Lima3, P. P. Batista1, B. R. Clemesha1, and K. Shiokawa4 H. Takahashi et al.
  • 1Instituto Nacional de Pesquisas Espaciais, INPE, CP-515, 12245-970 São José dos Campos, SP, Brazil
  • 2Department of Electronic & Electrical Engineering, University of Bath, Bath, BA2 7AY, UK
  • 3Dept. Física, Universidade Estadual de Paraíba, Campina Grande, PB, Brazil
  • 4Solar Terrestrial Environmental Laboratory, STEL, Nagoya University, Toyokawa, Aichi 442-8507, Japan

Abstract. Common periodic oscillations have been observed in meteor radar measurements of the MLT winds at Cariri (7.4° S, 36.5° W) and Ascension Island (7.9° S, 14.4° W) and in the minimum ionospheric virtual height, h'F, measured at Fortaleza (3.9° S, 38.4° W) in 2004, all located in the near equatorial region. Wavelet analysis of these time series reveals that there are 3–4-day, 6–8-day and 12–16-day oscillations in the zonal winds and h'F. The 3–4 day oscillation appeared as a form of a wave packet from 7–17 August 2004. From the wave characteristics analyzed this might be a 3.5-day Ultra Fast Kelvin wave. The 6-day oscillation in the mesosphere was prominent during the period of August to November. In the ionosphere, however, it was apparent only in November. Spectral analysis suggests that this might be a 6.5-day wave previously identified. The 3.5-day and 6.5-day waves in the ionosphere could have important roles in the initiation of equatorial spread F (plasma bubble). These waves might modulate the post-sunset E×B uplifting of the base of the F-layer via the induced lower thermosphere zonal wind and/or the E-region conductivity.

Publications Copernicus
Download
Citation