Driving and Quenching of Zonal Flows on Gas Giants

Explore a 51-minute lecture examining the fierce east-west winds in the outer convective envelopes of Jupiter and Saturn, drawing on gravity measurements from the Juno and Cassini missions. Delve into 3D magnetohydrodynamic simulations that reveal how zonal winds are driven in gas giant atmospheres and the mechanisms behind their depth limitations. Learn how the primary jet formation occurs through upscale transfer directly from small convective scales, bypassing large-scale structures, rather than through an inverse cascade. Discover the role of Reynolds stresses in driving jet formation through statistical correlations of velocity components in small-scale convective flows. Examine evidence for a stably stratified layer at the base of the zonal winds that acts as a lower boundary, explaining the depth constraints observed in gravity measurements.