OBSERVATIONS OF ALTITUDINAL AND LATITUDINAL E-REGION NEUTRAL WIND GRADIENTS NEAR SUNSET AT THE MAGNETIC EQUATOR

Sounding rocket chemical release measurements of the E-region neutral wind profiles were carried out at the magnetic equator at dusk on two consecutive days in September 1994 when a strong prereversal enhanceme nt of the F-region vertical plasma drift was present. Wind profiles we re obtained at the equator and similar to 450-480 km further north. Th e profiles show wind speeds of 80-100 m s(-1) in the lower E-region an d reversals of the wind direction over vertical scales of 10-15 km. On bath days, the wind direction in the lower E region changed consisten tly between the northern and equatorial releases, with a strong southw ard wind evident at the northern position and a stronger eastward wind at the equator.