Synopsis of the GEM program from the GEM website at http://www.cpe.vt.edu/gem/

'The Geospace Environment Modeling (GEM) program is a National Science Foundation (NSF) Division of Atmospheric Sciences initiative to coordinate and focus research on the near-earth portion of geospace from the lower ionosphere to where the earth system interacts with the solar wind. The purpose of GEM program is to support basic research into the dynamical and structural properties of geospace, leading to the construction of a global geospace general circulation (GGCM) model with predictive capability. The GGCM effort is now being treated as a separate campaign. The strategy for achieving GEM goals is to undertake a series of campaigns, in both theory and observational modes, each focusing on particular aspects of the geospace environment.'