Methods for Studying Influence of Io Magma Ocean on Alfvén Wings

Abstract: The most volcanically active body in the solar systemand the innermost Galilean moon of Jupiter, Io, is theorizedto have a global magma ocean beneath it’s surface. Io is alsoin a fast-moving flow of plasma where the moon acts as anobstacle in the flow which generates several complex interactions.One important interaction is the propagation of Alfv ́en waves,a specific wave in plasma, and the associated creation of Alfv ́enwings. The proposed magma ocean on Io would give rise to aninduced magnetic field and this induced field would influencethe shape and direction of these Alfv ́en wings. In this project,our aim is to find out how the induced magnetic field from themagma ocean would affect Io’s Alfv ́en wings and then comparethe results of our studies with measurements from the NASAGalileo spacecraft. We want to develop methods that we can applyto the measured magnetic field data from a specific spacecraftflyby to find out where the spacecraft enters and exits the Alfv ́enwing. Two different methods will be attempted, one that examinesthe gradient of the measured magnetic field and one that createscross-sections of these Alfv ́en wings and track the spacecraftstrajectory through it. Our results show that the methods wedevelop for examining the Alfv ́en wings are efficient, but thegeometry of the spacecrafts trajectory is not useful for studyingthe influence of the induced fields on the Alfv ́en wing. Thislimits us in drawing any definite conclusions about the existenceof a global magma ocean. Future spacecraft flybys with bettertrajectories are needed to use our methods to decide whether amagma ocean exists or not.