Comparison of Two Different Techniques to Derive the Electric Current Density in the Ionosphere

Instantaneous global ionspheric conductance maps during substorms can be derived by using PIXIE and UVI data from the Polar satellite, covering an electron energy range between approximately 0.1 and 100 keV. Mesoscale instantaneous conductance profiles can be inferred from the MIRACLE ground-based network in Northern Scandinavia, using electric field measurements of the STARE coherent scatter radar and ground magnetometer data of the IMAGE network. For this purpose, the 1D method of characteristics is used. First comparison results of these two techniques are presented. The computed Hall and Pedersen conductance distributions from Polar and MIRACLE are then combined with the electric field data to derive the true electric current density in the ionosphere in the Northern Scandinavian region. We also use observations of the ground-based magnetometer network to derive the equivalent ionospheric electric current density over the whole Scandinavian area.