What Are the Ionospheric and Ground Magnetic Signatures of Global Magnetopause Surface Modes?

Surface waves on Earth’s magnetopause act as an efficient mechanism of filtering, accumulating, and guiding the turbulent disturbances present in the solar wind into terrestrial space, thereby playing a key role in controlling global magnetospheric dynamics. However, it is difficult to directly measure these processes since orbiting spacecraft often only provide sparse observation points. It would, therefore, be desirable to be able to remote sense magnetopause surface modes via ionospheric radar or networks of ground magnetometers. The Alfvénic signatures of localised, tailward propagating magnetopause surface waves in ionospheric and ground magnetometer data are somewhat established. However, those associated with the global-scale compressional surface eigenmodes – the lowest frequency and largest-scale normal mode of the magnetospheric system – remain poorly understood. In this presentation we discuss how high-resolution global magnetosphere simulations coupled to an ionosphere model may be able to predict the qualitative features expected in ground-based instruments. Finally, we compare the results of our simulation to simple theory and reported potential observations.