|
|
 |
|
|
Ann. Geophys., 24, 2481-2491, 2006
www.ann-geophys.net/24/2481/2006/
© European Geosciences Union 2006
Gravity waves observed from the Equatorial Wave Studies (EWS) campaign during 1999 and 2000 and their role in the generation of stratospheric semiannual oscillations
V. Deepa1, G. Ramkumar1, and B. V. Krishna Murthy2
1Space Physics Laboratory, Vikram Sarabhai Space Centre, Trivandrum-695 022, India
2B1 Ceebros, 47/20, IIIrd Main Road, Gandhi Nagar, Adayar, Chennai-600 020, India
Abstract. The altitude profiles of temperature fluctuations in the stratosphere and
mesosphere observed with the Rayleigh Lidar at Gadanki (13.5° N,
79.2° E) on 30 nights during January to March 1999 and 21 nights during February
to April 2000 were analysed to bring out the temporal and vertical
propagation characteristics of gravity wave perturbations. The gravity wave
perturbations showed periodicities in the 0.5–3-h range and attained
large amplitudes (4–5 K) in the mesosphere. The phase propagation
characteristics of gravity waves with different periods showed upward wave
propagation with a vertical wavelength of 5–7 km. The mean flow acceleration
computed from the divergence of momentum flux of gravity waves is compared
with that calculated from monthly values of zonal wind obtained from RH-200
rockets flights. Thus, the contribution of gravity waves towards
the generation of Stratospheric Semi Annual Oscillation (SSAO) is estimated.
Full Article in PDF (1352 KB) |
|
|
