Model study of the earth’s ionosphere electric currents system at high latitudes

Abstract

This paper presents a numerical study of the response of high- latitudinal Earth’s ionosphere electric currents system to different magne- tospheric inputs. The ionosphere states were modeled using the Upper At- mosphere Model (UAM). The magnetospheric inputs were specified using two models of field-aligned currents (FACs), namely, the classical Iijima & Potemra model (UAM-IP variant) vs. the MFACE model (UAM- MFACE variant). Model results showed that the UAM-IP variant did not allow specifying FACs independently at each hemisphere while the UAM- MFACE version did. The inclusion of the IMF dependence in the UAM extended the modeling facility. The UAM-MFACE version reproduced the high latitudinal ionosphere currents and the geometry of the auroral oval better than the UAM-IP version. At the same time, UAM-MFACE required an extended list of input parameters, a specific spatial grid, and finer time-steps.