First results of the tidal structure in the MLT revealed by Wuhan Meteor Radar (30°40′N, 114°30′E)

Abstract

On the basis of the first year of neutral wind data measured by a meteor radar in Wuhan, the tidal structure in the MLT is studied. The diurnal tide component is the dominant tide over Wuhan, while the semidiurnal and terdiurnal tide are much weaker. According to the variation of diurnal tide phase, the diurnal tide can be shown to propagate upward with vertical wavelengths between 30 and 50 km . The diurnal tide amplitudes tend to show maximum values in spring and autumn. The maximum zonal and meridional diurnal amplitudes are approximately 40 and 60 m/s , respectively. A comparison of the observed diurnal tide with GSWM00 values shows similar phase variations with height, but discrepancies in amplitudes. The observed diurnal tide maximizes below 95 km , however the model amplitude increases with altitude. The agreement of model and the observed diurnal amplitudes are good in summer and winter, but in autumn the model amplitudes are much greater than the observed values. The analysis on semidiurnal tides indicates the maximum amplitudes in both zonal and meridional components are about 28 m/s . The agreement between the model and the observed values of semidiurnal tide is not so good. The observed amplitude of the semidiurnal tide does not show any resemblance to the model value. The observed amplitudes are greater than the model in spring and summer. The phase difference between the model and observed values may exceed 3 h in spring and winter.