Storm-Substorm Relationships During the 4 October, 2000 Storm. IMAGE Global ENA Imaging Results Pontus C:son Brandt, Donald G. Mitchell, Shin Ohtani, Robert Demajistre, Edmond C. Roelof, Jorg-Micha Jahn, Craig Pollock Geoff Reeves Global ion distributions in the 1-200 keV energy range from the main phase of the geomagnetic storm on 4 October 2000 are presented and analyzed. Proton distributions have been obtained by inverting energetic neutral atom (ENA) images from the high energy neutral atom (HENA) instrument on board the IMAGE satellite using a constrained linear inversion technique. The storm is characterized by a 24-hour long main phase where the IMF B steadily decreases followed by a 2 day recovery. Several substorms occured during the main phase as can be seen from in-situ measurements from geosynchronous satellites (LANL, GOES). Substorm injections during the early main phase, when the dawn to dusk electric field was weak, ocurred on closed trajectories. A strong asymmetric ring current developed as the IMF B decreased gradually to about -10 nT. A substorm ocurred at about 17:30 UT which injected plasma onto open trajectories with no clear change in the morphology of the partial ring current. As the IMF B increased towards zero, substorms were observed to inject ions onto closed trajectories. The peak of the ring current moved from L=5 to L=3 during the entire main phase. A preliminary inspection of 80-160 keV oxygen ENA fluxes reveal a one order of magnitude increase during the entire main phase, implying that O+ contributed significantly to this storm. Rapid decrease followed by decay (1 h) was superposed on the gradual increase of the oxygen ENA. Each one of these "bursts" are associated with a substorm onset. No burst-like features were present in the hydrogen data. In order to quantify the variations in the ring current energy content, the equivalent magnetic disturbance D(ENA) is calculated for the L<=6 proton distributions using the Dessler-Parker-Sckopke relation. Our calculated D(ENA) suggests that substorm proton injections did not increase the ring current energy content over the main phase. Together with the fact that the proton ring current was mostly partial, this shows that the dominant ring current energy increase must have been due to increased convection. However, the long-term increase in oxygen ENA fluxes suggests that O+ may have been continuously extracted from the ionosphere throughout the main phase and subsequently energized at each substorm dipolarization to give rise to the oxygen ENA bursts. We also discuss implications of strong electric fields in the inner region L<4. _______________ AGU Monograph on the Storm-Substorm Relationship, 142, 103-118, doi:10.1029/142GM10, 2004.