This project will purchase a 100 node, AMD Opteron based, computer cluster for geospace and plasma modeling. The cluster will be used by four research groups in the University of New Hampshire Institute for the Study of Earth, Oceans, and Space (EOS) who study related processes with similar tools. Specifically, the cluster will be used to model Earth's magnetosphere - ionosphere - thermosphere system and its interaction with the solar wind and the interplanetary magnetic field, simulations of magnetic reconnection and turbulence in plasmas, modeling Earth's ring current, kinetic modeling of collisionless shocks and the acceleration of particles, modeling the impact of cosmic rays on Earth's climate, and simulations of strongly coupled dusty plasmas. The computer cluster will significantly enhance the University of New Hampshire's ability to model these complex and highly coupled systems. Most of the simulation codes that will be used are already mature, and the impact of the cluster on scientific productivity will therefore be immediate. The research to be performed on the cluster has societal impacts because it is directly related to problems related to space weather and it will improve our ability to forecast and nowcast space weather, and to understand and to mitigate its effects. The National Space Weather Program explicitly calls for the development of such capabilities. The cluster will also make an impact on the education of students in all physical disciplines at UNH by giving them access to a state-of-the art computing facility. This project will thus directly contribute to the education of the next generation of scientists.