THE MECHANISM OF ACCELERATION OF RING CURRENT DURING A SUBSTORM OF MAGNETOSPHERE

Aprocess of turbulent dynamo action which leads to the growth of ring current is described in this peper.Owing to the strong magnetic field in the magnetosphere,the magnetic field configuration essentially satisfies the approximation of the force-free field.On the other hand,the fluctuating value of magnetic field is comparable to the mean value,When the electromotive force of the fulctuating field grows,the mean field and current density may grow in such a way that ring current is increased.Obviously,the turbulent or fluctuating field supplies the energy which keeps ring current during a substorm.This is a process of the acceleration of particles.Amodel of α²-turbulent dynamo is discussed specifically in this paper,and an eigenmodel of exponential growth of time is obtained The results of analysis have been used in discussing the process of ring current during a substorm,and a quantitative estimate has been made.