Search

Using the meteor radar data at the Mohe (53.5° N, 122.3° E) and Wuhan (30.5° N, 114.2° E) regions over China, this paper conducts a study on the diurnal and seasonal variation of high-frequency (within 2 h) gravity waves (GWs) activity in the mesosphere and the lower thermosphere (MLT). On the basis of the composite day analysis and Hocking's technique, the variance and momentum flux of the high-frequency GWs are derived from the radial velocities of individual meteor trails. Spectral results demonstrate that the high-frequency GWs activity shows 12 and 24 h periodicity, which may be due to the tidal modulation on the high-frequency GWs. The spectra of the variance and momentum flux also show 6 and 8 h periodicity. In addition to the diurnal variation, the high-frequency GWs activity shows the annual and semiannual oscillations. Additionally, the quasi-4-month oscillation is found at Mohe. [ABSTRACT FROM AUTHOR]

This paper compares the wind fields measured by the meteor radar at Mohe, Beijing, Wuhan, and Sanya stations and horizontal wind model (HWM14) predictions. HWM14 appears to successfully reproduce the height-time distribution of the monthly mean zonal winds, although large discrepancies occur in wind speed between the model and measurement, especially in the summer and winter months. For meridional wind, the consistency between model prediction and radar observation is worse than that of zonal wind. The consistency between radar measurements and model prediction at Sanya station is worse than other sites located at higher latitudes. Harmonic analysis reveals large discrepancies in diurnal, semidiurnal, and terdiurnal tides extracted from meteor radar observations and HWM14 predictions. [ABSTRACT FROM AUTHOR]