SPECTRAL ANALYSIS OF ATMOSPHERIC FLUCTUATIONS IN THE POLAR MESOSPHERE

Observations with the mobile SOUSY VHF radar at Andφya (69°N,16°E)during the MAC /SINE campaign in the summer of 1987 are used to calculate the Vertical wavenumber spectra and frequency spectra.Vertical wavenumber spectra have slopes close to -2.70, -2.65 and-1.55 for the zonal,meridional and vertical winds,respectively. Frequency spectra have slopes close to -1.44,- 1.30 and -0.27 in the range 6h-30min periods for the three velocity components.It is found that the horizontal wind spectra are in resonable accord with the 2D turbulence theory or gravity wave spectral theory.The inconsistency of vertical wind spectra to the gravity wave spectral theory can not be explained by the Doppler-shifting effects. This shows that the spectra of atmospheric waves may consist of components other than the gravity waves.