Recorded 30 January 2025. Simon Cabanes of the Institut de Physique du Globe de Paris (IPGP) presents "Formation of zonal jets in the subsurface oceans of the Jovian and Saturnian moons" at IPAM's Rotating Turbulence: Interplay and Separability of Bulk and Boundary Dynamics Workshop. Abstract: The subsurface oceans of Jupiter's and Saturn's icy moons—Europa, Ganymede, Enceladus, and Titan—are key targets in the search for extraterrestrial life. To study their global ocean circulation, we conducted 21 simulations of Boussinesq thermal convection in rapidly rotating spherical shells, driven by temperature contrasts and constrained by no-slip boundaries. Our simulations exhibit a dynamic global circulation that combines powerful east–west zonal jets, planetary waves, and vortices. By assuming that kinetic energy dissipates via Ekman friction at the ice–ocean boundary, we predict an upper bound for the geostrophic zonal velocity ranging from a few centimeters per second for Enceladus to about one meter per second for Ganymede. These predictions yield typical jets size approaching the ocean depth of Titan, Ganymede and Europa and 10 to 40% of the ocean depth on Enceladus. In addition, our research shows that Ganymede's oceanic flow generates its own magnetic field, a phenomenon that will be detectable by the magnetometers of the ESA’s JUICE space mission. This discovery opens up the exciting possibility of mapping the oceanic flow on Europa and Ganymede using magnetic data from the upcoming NASA’s Europa Clipper and ESA’s JUICE missions. Learn more online at: https://www.ipam.ucla.edu/programs/workshops/rotating-turbulence-interplay-and-separability-of-bulk-and-boundary-dynamics/