The global magnetospheric impacts of ICME mesoscale magnetic field variations

Coherent structures and random plasma variability at intermediate scales—between the large heliospheric structures such as interplanetary coronal mass ejections (ICMEs) and kinetic scales—have attracted growing attention within the solar wind and ICME community. This mesoscale variability in the solar wind has been shown to introduce uncertainty in the prescribed driving conditions of the magnetosphere, as in situ spacecraft upstream of the Earth’s magnetosphere do not always represent the actual solar wind forcing. Here, we demonstrate the global magnetospheric impacts of ICME mesoscale magnetic field variations. Using the Geospace configuration of the Space Weather Modelling Framework, we simulate the magnetospheric environment and, for the first time, capture a non-linear magnetospheric response that results from differences in the time-history of the driving conditions. Our results highlight the importance of understanding the longitudinal mesoscale variations in the solar wind to accurately interpret magnetospheric dynamics resulting from solar wind energy input into the system.