Graff, A.A.Graff2022-03-022022-03-021988https://publica.fraunhofer.de/handle/publica/175467Calculations of the decay parameter of the equatorial ring current are generally made under consideration of the momentary injection, which is calculated from interplanetary parameters. Hereby values of the order of 6 h result. However the author's investigations of 23 storms from 1966 to 1977 have shown that the ring current decays in a much slower manner. A time constant of about 20 h has been found. This is obviously caused by the fact that the decay event of the ring current is not disturbed by the injection at the beginning of the recovery phase. It is supposed that at this time the ring current region can no longer be reached by the injection. Therefore it is not justified to consider the injection at the beginning of the recovery phase for the calculation of the decay parameter.enmagnetospheread 1966 to 1977recovery phase injectiondecayring currentequatorial ring current621520journal article