The EEF causes vertical E B plasma drift upward at the dip
equator.This vertical ion drift lifts equatorial plasma to altitudes
above 800 km which then diffuses down magnetic field lines
to form dense bands of plasma on either side of the magnetic
equator at low latitudes (about 15 north and south of the dip
equator).This is known as the equatorial ionospheric anomaly
(EIA) (Appleton,1954;Anderson,1981). The vertical ion drift,whose velocity is E B=B2 provides the opportunity to directly
measure the EEF from Doppler shifts in radar echoes