Modelling studies of the effects of cusp inputs on the polar ionosphere
A new numerical model of the high latitude ionosphere is used in conjunction with data from the EISCAT radar facility to study the formation and structure of polar patches. Inputs based on the ionospheric signature of a Flux Transfer Event (FTE) are used in the model. It is found that a region of decreased O+ and increased molecular ion concentration is produced in the cusp region of the polar ionosphere. Ion temperatures are observed to be greatly enhanced in this region, which leads to an increase in the recombination rate resulting in the alteration of the ion concentrations. The electron temperature is less enhanced than the ions. Large upward fluxes transport plasma to higher altitudes where it is stored and released several hours after the FTE has finished, as the flux tube convects across the polar cap.