Seasonal behavior of equivalent winds over Wuhan derived from ionospheric data in 2000–2001 Original Research Article

The equivalent winds are derived from digisonde measurements over Wuhan (114.4°E, 30.6°N, 45.2° dip) to investigate their seasonal behavior during the years 2000–2001. The results show that the diurnal pattern of the vertical equivalent winds (VEWs) has a prominent seasonal variation. The VEWs are larger upward in summer and larger downward in winter. The VEWs over Wuhan show an equinox asymmetry, i.e., VEWs in vernal equinox have smaller magnitudes than those in autumn equinox. Midnight descent of VEWs is more distinct in fall and winter, but not obvious in spring. The rise occurs in the early morning for all seasons. The VEWs are decomposed to investigate the seasonal difference of the tidal components. Neutral winds estimated from the VEWs are compared with those predicted by the empirical neutral wind model, HWM93. It shows reasonable agreement except for some local time intervals.