Field-Aligned Current Structures During the Terrestrial Magnetosphere's Transformation into Alfven Wings and Recovery

On April 24th, 2023, a CME event caused the solar wind to becomesub-Alfvenic, leading to the development of an Alfven Wing configuration in theEarth's Magnetosphere. Alfven Wings have previously been observed as cavitiesof low flow in Jupiter's magnetosphere, but the observing satellites did nothave the ability to directly measure the Alfven Wings' current structures.Through in situ measurements made by the Magnetospheric Multiscale (MMS)spacecraft, the April 24th event provides us with the first direct measurementsof current structures during an Alfven Wing configuration. We have found twodistinct types of current structures associated with the Alfven Wingtransformation as well as the magnetosphere recovery. These structures areobserved to be significantly more anti-field-aligned and electron-driven thantypical magnetopause currents, indicating the disruptions caused to themagnetosphere current system by the Alfven Wing formation.