[1] A sudden increase in the solar wind dynamic pressure compresses the magnetosphere and launches compressional waves into the magnetosphere. The global response of the magnetosphere, including the ionosphere and the location of the field-aligned current (FAC) generation, to a step increase in the solar wind density has been studied using a global three-dimensional adaptive MHD model. As the density increase propagated along the flanks of the magnetopause, a two-phased response was seen in the ionosphere. The first response was an increase in FACs near the polar cap. For this response we found the location of FACs to lie just inside the magnetosphere. The second response was an increase in FACs at lower latitudes. The increase in FACs was in the same direction as region 1 currents. For the second response we found the location of FACs to fall well within the magnetosphere.

No abstract

[1] The effect of magnetospheric substorms on the ring current is not completely understood. Using a combination of the University of Michigan's BAT-S-RUS Model and Fok Ring Current Model, we modeled the effects of multiple substorms on the ring current by modeling multiple dipolarizations in the tail. Increasing the number of substorms corresponds to increases in the number of injections into the ring current. The ionospheric potential increases during periods of southward IMF. Energy increases are more dependent on the duration of large ionospheric potential than the number of substorm dipolarizations.

Abstract. The Kelvin-Helmholtz instability is a mechanism for transport of mass and momentum from the solar wind to the magnetosphere. Using a two-dimensional compressional MHD simulation, we explore the mass and momentum transport at the boundary for different magnetic field configurations corresponding to the flank low-latitude boundary layer. We used data taken from Phan and Paschmann [ 1996] and Paschmann et al. [ 1993] to better approximate the density and magnetic field structure of the boundary layer for low-and high-shear magnetic fields. We found that mass transport was the largest for the low-shear magnetic field configuration where the magnetic field in the magnetosheath was almost parallel to the magnetospheric magnetic field. The largest momentum transport occurred for cases where the magnetic field in the magnetosheath was parallel or antiparallel to the magnetospheric magnetic field.