Energy Transfer between the Solar Wind and the Magnetosphere-Ionosphere System

Abstract

The coupling of energy between the solar wind and the magnetosphere has been studied using many different techniques. Early research used simple statistical methods and cross-correlation analyses. Such work suggested that solar wind-magnetosphere coupling is strongly controlled by the interplanetary electric field (-V × B). Later studies have used more sophisticated techniques such as linear prediction filtering to understand quantitatively the time scales and efficiency of such coupling. In fact, there emerge two distinct aspects and time scales for coupling processes: (1) Directly-driven ionospheric dissipation with response time scales of 10-20 min.; and (2) Storage-release mechanisms involving energy loading in the magnetotail for-1 hour. Very recent research has used nonlinear dynamical models and nonlinear filter techniques to incorporate both directly driven and loading-unloading behavior. The result is that very accurate predictions of magnetosphere-ionosphere response are possible using state-input space reconstruction and “nearest neighbor” nonlinear filters.