Modulating Solar Wind Fluctuations in a Global MHD Simulation of a CIR

As high speed streams interact with slower solar wind ahead, they create compressed regions known as the corotating interaction regions (CIR). Geomagnetic storms generated by CIRs are thought to obtain a significant of their strength due to the magnetic fluctuations in the z component of the magnetic field. These fluctuations are from Alfven waves in both the CIR and the following high speed stream. Using a real CIR event as our baseline, we enhanced the fluctuation amplitude and dampen various frequency ranges of fluctuation in both the z component of the magnetic field and its corresponding velocity. The Lyon-Fedder-Mobarry (LFM) global MHD simulation was driven using these modified solar wind conditions. The modifications were done in incremental steps with only one modification made per simulated event. This will allow us to gauge which simulated event, and its corresponding modified parameter, contributes to the geomagnetic storm's strength. We will present a comparison of each simulated event and their various characteristics, such as the cross-polar potential, integrated Birkeland currents, and open magnetic flux.