Simulation of the polar cap F region ionization using an experimental convection electric field

The electrons and ions concentration over the polar cap F region was calculated with a code running on a vectorial computer. Four coupled continuity equations, one for each ion specie, are solved together with the momentum equation, assuming that the in velocities and temperatures are the same for all species. The transportation of the ionization is due to neutral wind drag, the electric field and the ambipolar diffusion velocity which includes a stress tensor for taking account of the anisotropy created by the intense electric field encountered in the polar cap. The horizontal ion transportation is due to the planetary convection electric field which is deduced from 24 hours EISCAT observations during a quiet day. Because the observations are limited northward in latitude it is necessary to interpolate the equipotential lines providing reasonable physical assumption. Then the experimental convection electric field is replaced by a theoretical one. Results from the simulation of the ions concentration with the two convection models are compared. These results are compared also with the EISCAT electron density measurements.