We present the results of self-consistent one-dimensional hybrid code (kinetic ions and fluid electrons) simulations of a dipolarizing field reversal. Local ion energization processes are studied in terms of both the ion kinetics and bulk plasma behavior. We demonstrate evolution of the system through two phases: (1) a quasi-static ''trapping'' phase, during which inflowing ions are trapped in the reversal structure at early times and (3) a dynamic ''escape'' phase, during which trapped ions escape from the reversal after an increase in P∥. We perform simulations with different linking field component (GSE Bz) to reversing component (GESE Bx) ratios and show that this parameter controls the details of the ion energization. This study suggests a characteristic signature in the magnetic field (a bipolar By) and bulk plasma parameters (an increase in P∥) associated with this behavior which should be observable in in situ data. Our results are applicable for times earlier than the midtail to ionosphere Alfv¿n travel time. ¿ American Geophysical Union 1994