The Eye of the Geomagnetic Storm: Electrodynamics at High-Latitudes during Geomagnetic Storm

Abstract: 

The Earth’s magnetosphere is coupled to the solar wind, and the ionosphere. The solar wind-magnetosphere coupling gives rise to electrical currents which flow through the magnetosphere and come together in the ionosphere. These currents are carried by the electrically conducting plasma which surrounds our neutrally charged atmosphere. The plasma adjusts to carry the currents, and in doing so, the plasma circulates the magnetospheric system. This is known as plasma convection and it can be measured near the geomagnetic poles by ground- and space-based instruments. In this talk, I will introduce the Super Dual Auroral Radar Network and how its data, now spanning several decades, can be utilised to measure plasma convection. Measuring the plasma convection allows us to remote sense what happens in geospace, including the time-varying nature of magnetospheric activity, and the magnetosphere’s non-linear response to solar wind driving, which we can measure in plasma convection strength and morphology.

During geomagnetic storms for example, when the solar wind driving of the magnetospheric convection is high, we see the plasma convection span a larger area than previously thought, which is not described by conventional high-latitude electric field models. Since the ionosphere interacts with the neutral atmosphere, it is crucial for whole atmosphere models to appropriately incorporate the high-latitude ionosphere. In this talk I will demonstrate why this becomes important when we model the magnetospheric system for space weather purposes, or the atmosphere for climate purposes, and how we can leverage the SuperDARN dataset to build improved models for a better understanding.