Jupiter's Overturning Circulation: Breaking Waves Take the Place of Solid Boundaries

Abstract

Cloud‐tracked wind observations document the role of eddies in putting momentum into the zonal jets. Chemical tracers, lightning, clouds, and temperature anomalies document the rising and sinking in the belts and zones, but questions remain about what drives the flow between the belts and zones. We suggest an additional role for the eddies, which is to generate waves that propagate both up and down from the cloud layer. When the waves break they deposit momentum and thereby replace the friction forces at solid boundaries that enable overturning circulations on terrestrial planets. By depositing momentum of one sign within the cloud layer and momentum of the opposite sign above and below the clouds, the eddies maintain all components of the circulation, including the stacked, oppositely rotating cells between each belt‐zone pair, and the zonal jets themselves.

Ammonia Abundance Derived from Juno MWR and VLA Observations of Jupiter

“…The pressure range over which mixing occurs is consistent in the extratropical region, where the mixing occurs over a rather small pressure range (5 bars), as shown in Figure 20(e). This mixing is very consistent across uncertainties and much more localized in pressure than the results shown in Ingersoll et al (2021), which derived a map based on both limb-darkening and nadir brightness temperature information.…”

“…This agrees with the conclusion by de Pater et al (2019b), who showed that ammonia abundance profiles by Li et al (2017) gave an inferior fit to the data as compared to their derived abundance profile. Similarly, Ingersoll et al (2021) used PJ1-PJ7 observations and did not find a structure consistent with an inversion at midlatitudes.…”

Evidence for Multiple Ferrel‐Like Cells on Jupiter

“…Indications for the upper cells come from measurements of temperature and shallow tracer distributions (de Pater et al., 2019; Fletcher et al., 2016; Gierasch et al., 1986). Similar to the balance describing the deeper branch of the lower cells, the upper branch of the upper cells requires a drag force, which may result from breaking of atmospheric waves (Gierasch et al., 1986; Ingersoll et al., 2021).…”

Mid-Infrared Observations of the Giant Planets

“…This full picture of the gas giant circulations becomes more complicated when one also considers the distribution of storms, deep ammonia, and microwave radiances-all of which potentially point towards deeper, vertically coincident, but directionally opposite circulation cells ("stacked" circulation cells) on Jupiter [345][346][347][348][349]. A discussion of this circulation is beyond the scope of this review, but see Fletcher et al, [334] for a comprehensive review.…”