Alfvénic Contribution From the Solar Wind to Magnetospheric Dynamics

This paper proposes for the first time a theoretical expression for the injection of energy from the solar wind into the ring current due to Alfvénic fluctuations. Using interplanetary and geomagnetic measurements, we select four case studies, validate our approach, and compute the parameters involved in the proposed expression. Our results demonstrate that the linear trend in the recovery phase of geomagnetic storms associated with the passage of high speed streams, when compared to the exponential or hyperbolic trend, is not a different behavior of the magnetosphere, but the result of an injection of energy due to Alfvén waves, which was neglected in previous models.