Magnetosphere‐Ionosphere‐Thermosphere Coupling Study at Jupiter Based on Juno's First 30 Orbits and Modeling Tools

Abstract

We analyze the first 30 orbits of Juno to retrieve the properties of current systems and plasma flows associated with Jovian main auroras.• Southern hemisphere results are consistent with ionospheric plasma sub-corotation.• The two opposite patterns, sub-corotation and super-corotation, are observed in the northern hemisphere.

Simulation of Centrifugally Driven Convection in Jovian Inner Magnetosphere Using the Rice Convection Model

“…They are strongly correlated with particle precipitations and are significantly enhanced within the main auroral regions, outside of which the conductances are expected to become smaller (e.g., Al Saati et al., 2022; Wang et al., 2021). Strobel and Atreya (1983) suggested that the Pedersen conductance $${{\Sigma }}_{P}$$ is between 0.2 and 10 S , which is consistent with the values found with Juno data (Al Saati et al., 2022; Gerard et al., 2020; Wang et al., 2021). The Hall conductances $${{\Sigma }}_{H}$$ are usually 2–3 times larger than the Pedersen conductances (Wang et al., 2021).…”

A Juno‐Era View of Electric Currents in Jupiter's Magnetodisk

“…However, two significant differences appear between our equatorial and these previous polar observations. First, the latter generally found a two-subregion structure with an upward FAC on the equatorward side and a downward FAC on the poleward side, except for a minor fraction of northern flybys for which Al Saati et al (2022) observed the opposite trend. In contrast, our study finds an additional downward FAC on the equatorward side of the upward FAC.…”

“…By combining Juno multi-instrument data and modeling tools, Wang et al (2021) and Al Saati et al (2022) surveyed FACs and their other defined "MIT coupling Key Parameters" comprehensively during Juno magnetic footprint traversals of the main auroral emission. They found peak values of FACs (both upward and downward) in the northern and southern hemispheres of about 1 and 2 μA/m 2 , respectively.…”

“…It revealed that, although in the southern hemisphere the upward FACs are always located equatorward of the downward FACs, the pattern for the northern hemisphere is more complex. In about 70% of the northern flybys studied by Al Saati et al (2022), upward FACs are located on the equatorward side as well, while in the other northern flybys the opposite trend was observed. The latter trend indicates that the northern ionospheric plasma might be temporally in super-corotation, a phenomenon noted previously when studying the equatorial magnetic fields measured by Voyager 1 and 2 (Hairston & Hill, 1986).…”

“…They revealed a large north-south asymmetry in the magnitude of FACs, with northern FAC amplitudes being about half of southern FAC ones. Furthermore, development for Juno of a multi-instrument method linking UV and IR spectro-imaging observations of the main auroral emission to in situ magnetic field and electron precipitation observations made it possible to retrieve simultaneously the ionospheric components of field-aligned and horizontal currents that close the giant current loop connecting the magnetodisk to the ionosphere-thermosphere (e.g., Al Saati et al, 2022;Wang et al, 2021). It revealed that, although in the southern hemisphere the upward FACs are always located equatorward of the downward FACs, the pattern for the northern hemisphere is more complex.…”