In previous works, the authors used a simple model of the equatorial E and F regions to predict simultaneously zonal neutral and ion velocities and vertical currents at the base of the F region. In this work, the model is extended to include effects not considered previously: ion-neutral drag at the F region base, the E region dynamo electric field, and the F region zonal electric field. The model is used to predict the variables mentioned above as functions of time and latitude. The results of the calculations show first that the ion velocity is quite sensitive to the combination of the three effects, and a substantial improvement over previous results is found upon comparison with meaured values. The calculated zonal neutral wind also reveals the influence of ion drag through its latitudinal variations. Finally, the current density perpendicular to the geomagnetic field exhibits two pronounced peaks of the order of 10-7 A m-2 sunrise and sunset at the dip equator. ¿ American Geophysical Union 1987 |