Storm-Time Plasma Signatures Observed by MENA and Comparison with a Global Physics-Based Model M.H. Denton (LANL, Los Alamos, NM 87545), M.G. Henderson, V.K. Jordanova, M.F. Thomsen, R.M. Skoug, G.D. Reeves, S. Zaharia and C. Pollock The storm of 21st October 2001 provides an excellent opportunity to examine plasma dynamics during a major magnetospheric disturbance, using a variety of techniques. The MENA instrument on board the IMAGE satellite generates images of the global distribution of energetic neutral atoms in the energy range ~1-45 keV. These images reflect the global distribution of energetic ions, as "illuminated" by charge exchange with cold exospheric neutral atoms. We use the output from a global physics-based model of ring current evolution to generate simulated ENA images at various phases of the storm, for comparison with actual ENA observations made by the MENA instrument. This methodology gives an understanding of the energetic particle dynamics during the storm and provides a starting point for future planned experimental/theoretical investigations into storm-time proc-esses. ________________ Presentation at the Yosemite Conference of Inner Magnetospheric Interactions, 3 - 6 February 2004, Yosemite, California, USA