GPS Imaging of Magnetosphere-Ionosphere Coupling

Pokhotelov, D., Mitchell, C. and Spencer, P.

University of Bath, Bath, UK

The global pattern of the ionospheric plasma convection can be deduced from characteristics of GPS signals acquired by ground-based network of GPS receivers. The tomographic inversion of these GPS data in a three-dimensional time-dependent inversion algorithm based on Kalman filtering can reveal the spatial and temporal distribution of ionospheric electron density. This algorithm has been applied to reconstruct the 4D dynamics of ionospheric plasma content (TEC) and density during some major magnetic storms of the recent solar maximum. Comparison between the results of GPS tomography and in-situ measurements of plasma bulk motion by LEO satellites allow conclusions to be made about the degree at which the ionospheric convection flow expands during the major storms and the efficiency of electromagnetic magnetosphere-ionosphere coupling at sub-auroral latitudes.