ANALYTICAL MODELS OF THE MAGNETIC-FIELD OF DISK-SHAPED CURRENT SHEETS

Disk-shaped current distributions are useful tools in modeling the mag netospheres of Earth and other planets and have also been adapted for modeling the geotail. Such models usually start with an axisymmetric v ector potential but may be modified to account for observed asymmetrie s, variable thickness, and warping in response to an inclined Orientat ion of the planetary dipole axis. Models of this type until now either have lacked the ability to simulate a sharp inner edge of the current and to control accurately its falloff with distance or did not allow a simple analytical representation. Here existing methods will be revi ewed, after which a new class of models which overcomes the above defi ciencies and also allows the modeling of current disks of finite thick ness flanked by current-free regions will be presented.