Studies on planetary waves and tide interaction in the mesosphere/lower thermosphere region using meteor RADAR data from Rothera (68°S, 68°W), Antarctica

In this study, we report the interaction of planetary waves and tides observed in the mesosphere/lower thermosphere (MLT) region using a meteor radar located at Rothera (68°S, 68°W) Antarctica. The study has been conducted using wind data collected over the year 2005. The obtained data are subjected to wavelet analysis to determine the spectral content of the data and it was found that the MLT region is dominated by semidiurnal tide (SDT) and planetary waves with periods around 5, 10, 16 and 23 days. The behaviour of the semidiurnal tide was investigated and found to be very variable and modulated at the period of ∼23 days in the zonal component and at ∼5 and 16 days in meridional component. Non-linear interaction between the SDT and 16-day planetary wave in the meridional component was found to be mostly responsible for the variability of the SDT than the interaction between the SDT and 5 days in the meridional component and between the SDT and 23-day planetary wave in the zonal component. This was established by investigating the validity of frequency, phase and wavenumber relationship.