The High-Latitude Extension of Jupiter's Io Torus: Electron Densities Measured by Juno Waves

This is the supporting data set for the paper by the same title published in AGU JGR Space Physics, 10.1029/2021JA029195

Abstract

We present Jovian electron densities measured by the Juno Waves instrument at high-latitudes on magnetic field lines threading the Io torus using the first 29 orbits of the Juno mission. We infer electron densities from characteristic frequency cutoffs and resonances in plasma wave spectra. There are often times when more than one of the characteristic frequency of the plasma can be identified, whose consistency provides more credibility to the plasma density estimates. The majority of density measurements are on magnetic field lines threading the Io torus and intersecting Jupiter's ionosphere between Io's M-shell and the auroral main oval, but there is evidence of density dropouts near and within the auroral oval, which may be important in auroral particle acceleration. Sharp density gradients are found near the inner edge of the Io torus region. These observations demonstrate the extension of elevated Io torus densities along field lines to higher latitudes. 

Key Points

• We present Jovian electron densities at high-latitudes on magnetic field lines connected to the Io torus and plasma sheet
• Sharp density gradients are found near the inner edge of the Io torus M-shell
• Our densities are consistent with partial electron densities measured by Juno's Jovian Auroral Distributions Experiment