Tracking high-latitude ionospheric dynamics using ground- and space-based instruments
Abstract: The tomographic inversion of GPS electron content data in a three-dimensional time-dependent inversion algorithms combined with Kalman filters can reveal the spatial and temporal distribution of ionospheric electron density. These algorithms have been applied to reconstruct the large-scale 4D dynamics of ionospheric plasma content and density during some major geomagnetic storms. 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. Plasma dynamics/transport in the polar cap region is investigated using similar inversion methods and verified against the polar cap ionosonde data. Examples of tracking smaller-scale ionospheric disturbances (TIDs) with networks of GPS receivers are also presented. The results are discussed in the context of high-latitude ionospheric space weather.