This study presents a survey of ion flow speed, density, temperature, and composition observed by the Jovian Auroral Distributions Experiment Ion (JADE-I) sensor on Juno from 10–40 RJ in the dawn to midnight sector of Jupiter's magnetosphere. The survey covers Juno orbits 5–22, and the observations are separated by equatorial (|zmag[RJ]| ≤ 1.5) and off-equator (|zmag[RJ]|>1.5) regions. Plasma parameters for H+, O+, O2+, O3+, Na+, S+, S2+, and S3+ are derived by forward modeling JADE-I's energy-per-charge versus time-of-flight spectra using omnidirectional averaged convected kappa distributions and modeled instrument responses. O+ and S2+ are resolved via a ray-tracing simulation based on carbon-foil-effects. The ion flow speed increases with radial distance and is comparable to rigid corotation speed out to ∼20 RJ. Ion number densities decrease with radial distance, the primary species being H+, O+, and S2+. The relative contribution of H+ and S2+ increases and decreases, respectively, in the off-equator regions, supporting the interpretation that the latitudinal distribution of ions is mass dependent. The O+ to S2+ and ΣOn+ to ΣSn+ number density ratios are variable, the 5 RJ bin averages for O+ to S2+ ranging from ∼0.75–1.5 (equator) and ∼1.1–1.8 (off-equator) and ΣOn+ to ΣSn+ from ∼0.6–0.9 (equator) and ∼0.8–1.1 (off-equator). Both proton and heavy ion temperatures show order of magnitude increases between 10 and 20 RJ and range from ∼100 eV to 10 keV and 1 keV to a few tens of keV, respectively.
All Science Journal Classification (ASJC) codes
- Space and Planetary Science
- ion composition
- ion plasma parameters
- plasma sheet