Survey of Juno Observations in Jupiter's Plasma Disk: Density

Abstract

AbstractWe explore the variation in plasma conditions through the middle magnetosphere of Jupiter with latitude and radial distance using Juno‐JADE measurements of plasma density (electrons, protons, sulfur, and oxygen ions) surveyed on Orbits 5–26 between March 2017 and April 2020. On most orbits, the densities exhibit regular behavior, mapping out a disk between 10 and 50 RJ (Jovian radii). In the disk, the heavy ions are confined close to the centrifugal equator which oscillates relative to the spacecraft due to the ∼10° tilt of Jupiter's magnetic dipole. Exploring each crossing of the plasma disk shows there are some occasions where the density profiles are smooth and well‐defined. At other times, small‐scale structures suggest temporal and/or spatial variabilities. There are some exceptional orbits where the outer regions (30–50 RJ) of the plasma disk show uniform depletion, perhaps due to enhanced ejection of plasmoids down the magnetotail, possibly triggered by solar wind compression events.