Jupiter's Dawn Magnetosheath, Magnetopause, and Polar Flattening as Measured by Juno

Juno's 53-day orbit, with its apojove at 112 RJ, has spent a substantial amount of time in the magnetosheath on the dawn side of Jupiter and crossed the magnetopause boundary more than a hundred times. Juno first entered the magnetosheath on June 24, 2016 and the last recorded magnetosheath crossing occurred on January 6, 2018. It is increasingly unlikely that Juno will re-enter the magnetosheath until after orbit 30 (November 2020). Using the Jovian Auroral Distributions Experiment (JADE), the Magnetic Field Investigation (MAG) and the Waves Investigation (Waves), we present the statistical plasma properties of Jupiter's dawn magnetosheath, including magnetic field strength and directions, densities, plasma flow velocities, pressures, Alfvén speeds, and plasma betas, and their correlations. Characterizing Jupiter's magnetosheath properties is important to understand the frequency and efficiencies of magnetic reconnection and the Kelvin-Helmholtz instability at the magnetopause boundary. We search for these boundary effects in a survey of the magnetopause crossings and present the preliminary results. In addition, we present a new method of using the draping of the magnetic field in the magnetosheath to estimate the polar flattening of Jupiter's magnetosphere.