Effect of outer magnetosphere pre-conditioning on the inner magnetosphere during a magnetic storm

It has been suggested that the plasma sheet conditions prior to the main phase of a geomagnetic storm can have a significant effect on the storm development and the minimum Dst. In particular, northward IMF conditions leading up to the storm may load the plasma sheet with cold dense plasma and lead to stronger storms as opposed to those storms that lack a northward IMF phase before storm commencement. We use the OpenGGCM-RCM model to simulate storm events with northward IMF preconditioning before the storm commences. We will show in the simulation how a cold dense plasma sheet is formed in the mid-tail plasma sheet, how a super-dense plasma sheet develops near the inner magnetosphere boundary, and how this dense plasma affects the ring current and Dst index in the storm main phase. In order to quantify the effect we will present comparisons of simulations of the same storm with and without preconditioning by northward IMF.