ENA Observations of the Earth's Magnetosphere during the August 12, 2000 Geomagnetic Storm Pollock, C.J., J. Burch, D.J. McComas, J.-M. Jahn, R. Skoug, H.O. Funsten, E. Scime, M. Gruntman, D. Mitchell, T.E. Moore High quality Medium Energy Neutral Atom (MENA) Observations of the August 12 Geomagnetic Storm were obtained by the MENA imager on the IMAGE spacecraft and supported by high and low energy observations from the HENA and LENA imagers, respectively. The MENA observations are characterized by quite static topology throughout most of the day. Notably, the MENA observations often display a two component signature, including a diffuse component from high altitude emissions and a more intense low altitude component. The low altitude component may either be interpreted either as a purely geometric effect of the viewing angle, versus the pitch angle of mirroring particles at low altitudes, or as evidence of a filled loss cone. The two components have distinctly different temporal signatures. We will distinguish between the two interpretations of the intense, low altitude ENA component and document the disparate time histories of the two components. _______________ Presented at the Fall American Geophysical Union Meeting, San Francisco, CA., December 15-19, 2000