Speaker: Omakshi Agiwal
Affiliation: Boston University

Abstract:
Decades of spacecraft and telescope observations of Jupiter’s upper atmosphere reveal that plasma emissions, densities, temperatures and vertical structure do not appear to be controlled by sunlight alone. In this talk, I will present a recently developed unified picture in which neutral winds, acting along Jupiter’s spatially complex magnetic field via field aligned ion–neutral coupling, drive vertical transport that organizes the non auroral ionosphere and creates the steady spatial patterns seen in ~60 years of observations.

This unified view has been informed by 5 complementary studies: a reanalysis of ~6 decades of spacecraft radio occultations (Pioneer, Voyager, Galileo, Juno) which reveal significant variability in plasma vertical structure; over 175,000 spectra from ground-based telescopes (KECK/NIRSPEC), collected across four years, that produce high resolution global maps of ion densities and temperatures; a coordinated 2023 campaign (Juno, JWST, Keck) that delivered simultaneous continuous electron and ion vertical profiles; a new general circulation model of Jupiter’s thermosphere (JTIM) and ionosphere, which produces the first global wind maps consistent with observed temperatures; and a novel Jovian ionosphere model (JAMMIES) which includes an approximation of Jupiter’s magnetic field geometry and can reproduce various observed phenomena through its comprehensive treatment of ionospheric transport at Jupiter.

Finally, I will briefly discuss the outstanding mysteries still persist, concerning how such an ionosphere feeds back on magnetospheric currents, and the unknown drivers that control ionospheric dynamics in regions where neutral wind control is weak.

Submitted by: Omar Abuassaf (oabuassaf@epss.ucla.edu)