The Entry of Solar Wind Ions into the Magnetosphere During the 8 - 9 March 2008 CIR/HSS Geomagnetic Storm

We investigate the entry of solar wind ions into the magnetosphere during the 8 - 9 March 2008 geomagnetic storm event. The event begins with the arrival of a density plug associated with a corotating interaction region at 0730 UT on 8 March. The high-speed stream portion of the event begins at 1830 UT on 8 March, and minimum Dst for the storm, -86 nT, is reached at 0530 UT on 9 March. For this study, we carried out a global magnetohydrodynamic (MHD) simulation of the event using upstream solar wind and interplanetary magnetic field data, then used the three-dimensional time-dependent electric and magnetic fields from the MHD simulation to carry out a large-scale kinetic simulation of the event. We launched protons from the solar wind beginning at 0400 UT on 8 March at 1-minute intervals until the end of the main phase of the storm on 9 March. We examined the access of ions to the near-Earth plasma sheet and ring current throughout the event, and determined the entry locations of ions populating these regions as a function of the solar wind and IMF.