Numerical Simulations of the Geospace Response to the Arrival of an Idealized Perfect Interplanetary Coronal Mass Ejection

摘要

Previously, Tsurutani and Lakhina (2014, ) created estimates for a "perfect" interplanetary coronal mass ejection and performed simple calculations for the response of geospace, including dB/dt. In this study, these estimates are used to drive a coupled magnetohydrodynamic-ring current-ionosphere model of geospace to obtain more physically accurate estimates of the geospace response to such an event. The sudden impulse phase is examined and compared to the estimations of Tsurutani and Lakhina (2014, ). The physics-based simulation yields similar estimates for Dst rise, magnetopause compression, and equatorial dB/dt values as the previous study. However, results diverge away from the equator. dB/dt values in excess of 30 nT/s are found as low as 40 degrees magnetic latitude. Under southward interplanetary magnetic field conditions, magnetopause erosion combines with strong region one Birkeland currents to intensify the dB/dt response. Values obtained here surpass those found in historically recorded events and set the upper threshold of extreme geomagnetically induced current activity at Earth.