Current flow in the magnetosphere during magnetospheric substorms

A new model current system describing changes in real current flow in the magnetosphere associated with magnetospheric substorm activity is presented in this report. The physically new concept on which this current system is based is the lack of downflowing current in the night side magnetosphere during substorm expansion phase activity. The perturbation pattern stemming from the change in geometry of this new current system configuration can be calculated precisely by using the equivalent three-dimensional current loop discussed by Bonnevier et al. (1970).