An empirical model of the drift velocity of equatorial plasma depletions

摘要: [1] The Far-Ultraviolet Imager on the IMAGE spacecraft (IMAGE-FUV) has been used to observe O+plasma depletions in post-sunset equatorial ionosphere. Small-scale density irregularities associated with such are believed adversely affect trans-ionospheric radio signals as GPS. Prediction of motion these plasma is a necessary component ability forecast occurrence signal interference. An automated method recently developed identify and track position zonal drift velocity depletions. Here we use this create large database velocities We present an empirical model based observations that describes observed function both local time magnetic latitude, which essential represent their behavior. A comparison winds from (Horizontal Wind Model; HWM07) first-principles (the TIEGCM) reveals depletions' have latitudinal gradient cannot be explained solely by F-region dynamo period, at least climatological models. This suggests may not simply background plasma. It previously suggested vertical polarization electric fields responsible for drifts exceeding flow, explain previously-observed discrepancy gradients reported here.