A public domain data-based modeling of long-term variability of Jupiter’s inner electron radiation belt

<p>Until the arrival of Juno at Jupiter in 2016, the inner electron radiation belt dynamics has been examined from ground-based observations of Jupiter&#8217;s Synchrotron Emission (JSE) and theoretical modeling of the relativistic electron population. Simulations of JSE variability on month-to-year timescales only confirm a partial control of the Jovian Electron Radiation Belt (JERB) by large-scale solar-wind-driven particle transport. Juno prime mission and first years of the extended mission provide unique measurements of JSE from within JERB environment allowing us to further address the origins of JSE variability on a timescale of months.&#160;</p> <p>In the present work, we use Juno MicroWave Radiometer (MWR) data from mid-2016 to mid-2022 at different wavelengths to support our investigation of the origins of JERB dynamical behavior. Juno/MWR data from NASA Planetary Data System, ground-based observations of Jupiter and simulated Heliospheric Environment (HE) at the giant planet are combined to constrain the modeling of long-term variability of JSE as it would be observed from Earth. The Juno-data constrained trend of JSE at 11.5-cm wavelength is combined with single-dish observations to cover a multi-decade observation period. Using a simulator of JSE that accounts for the influence of physical parameters on jovian electron belts distributions, we present simulations of JSE to discuss the connection between JERB and HE and identify the magnetospheric physical processes (e.g., particle source and transport, interactions with planetary environment) which might have controlled JSE for the period 1962-2022.&#160;</p> <p>Acknowledgments: Key data processing, JERB model improvements and simulations of Juno/MWR measurements are carried out at Southwest Research Institute and primarily funded by NASA NFDAP program. This work benefits from collaborations with various Juno instrument teams and also from a larger science community.</p>