Abstract:
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Mainly due to the observational restrictions, in the past ionospheric modelling has been done either one-dimensionally in the vertical or field-aligned direction, or two-dimensionally in the horizontal direction. In the latter case, the ionosphere is typically assumed as an infinitely thin sheet, and all quantities used are height-integrated. However, the real ionosphere shows dynamical temporal variations in all three spatial dimensions simultaneously. New types of observations, like tomographic techniques or upcoming ionospheric multi-satellite missions, increasingly allow to obtain instantaneous three-dimensional views of the ionosphere. Therefore, it is necessary to devise new ionospheric modelling techniques which are able to incorporate effects which are neglected in the present models. With respect to ionospheric current systems, the main effects are ionospheric self- and mutual induction, and the possibility to close currents via vertical loops inside the ionosphere. Initial studies have already indicated that these effects can be highly important for the understanding of the magnetosphere-ionosphere coupling, especially under disturbed geomagnetic conditions.
The goal of the applied team is to gather an international group of experts who have started to work on the young field of three-dimensional ionospheric modelling in terms of current systems, induction effects, and the effects on ionosphere-magnetosphere coupling, in order to write a concise review on these topics. Further, the team will act as a think tankEfor finding new ways of improved three-dimensional ionospheric modelling.