Modelling the geomagnetic effect of the ring current based on the hourly mean parameters of the interplanetary medium.

The paper proposes two models of DR variations of the geomagnetic field on the basis of the equation of energy balance in the ring current, where average monthly parameters of the solar wind are used as the input data. The model, in which the injection function is made up of two parts (depending on the electric field and the solar wind velocity), makes possible a more accurate description of the recovery phase of magnetic storms in which the minimum value of DR is less than -190 nTl. Comparison with previously existing models demonstrates the improved accuracy achieved with the proposed model.