A study of geomagnetic storms

Abstract

An attempt is made to find interplanetary magnetic field and solar-wind parameters which control the development of geomagnetic storms. For this purpose, the interplanetary energy flux is estimated in terms of the Poynting flux (E×B/4π), and its time variations are compared with the rate of energy dissipation in terms of the ring-current particle injection ui(t), Joule dissipation in the ionosphere uj(t) and auroral particle injection up(t) for 15 major geomagnetic storms. A large increase of u(t) is associated with substorm activity. Thus, the energy flux ∈(t) entering the magnetosphere is dissipated through magneto-spheric substorm processes within the magnetosphere, and their accumulated effects can be understood as geomagnetic storm phenomena.