This grant will continue support of a research program aimed at the interaction of the solar wind and the magnetosphere. This interaction is important since it is the mechanism by which the magnetosphere is "pumped up' with magnetic energy. This magnetosphere eventually unloads this energy in a multitude of ways including the aurora. This grant has a nice combination of theory, numerical simulations and data analysis addressing the following areas: o analytic theory of non-linear Alfven waves. o spacecraft observations. o numerical simulation of shock related MHD waves. o quasi linear theory of beam instabilities Overall, this is a concerted program aimed at the elucidation of plasma processes occuring in the earth's bow shock.