This grant will support a program to develop a quantitative model for the global structure and dynamics of the solar wind- magnetosphere-ionosphere coupled system. It divides into four sub-projects: 1. Map the magnetic field that links the ionosphere to the solar wind through the dayside of the magnetosphere. The solar wind imposes its influence on the magnetopshere-ionosphere system mainly by attaching the magnetic field it carries with it onto the earth's magnetic field, which fills the magnetosphere the way air fills a balloon. The dayside of the magnetosphere is where the magnetic coupling takes place. Therefore, mapping the magnetic field in this region is important because it tells where the solar wind effect is concentrated, and it allows researchers to see the imprint of the attachment process at the ionospheric end, which is relatively accessible. 2. Develop a complete model of the magnetohydrodynamic structure of the global boundary of the magnetosphere. This is an extension of the first project, but the emphasis is on global completeness and explicit boundary architecture. 3. Work out the theory by which the solar wind communicates its influence to the ionosphere through electrical currents flowing between them on their linked magnetic field lines. And 4. Develop further and further apply a model which predicts the ionospheric winds that result from 3.. Overall the aim is to develop a global MHD picture of the way in which the sun's plasma energy couples down into the atmosphere.
