In planetary atmospheres, it is common that the outer atmospheric envelope contains highly turbulent flows powered by solar energy and by a heat flux from within the planet itself. These thermal energy sources transform into sources of atmospheric motion by driving turbulent eddies whose typical scales do not exceed a typical length scale of ∼ 2,500 km for both Jupiter and Saturn. It ensures the growth of powerful large scale zonal jets, that is east-west directed flow with 10,000–20,000 km latitudinal scale, and a host of waves and vortices, see Figure 1. On planets as Jupiter and Saturn, the jets are profoundly strong, their influence on the distribution of clouds is clearly visible even through relatively simple amateur telescopes, and their appearance is almost unchanging over hundreds of years since early observations. However, how these zonal jets form in planetary flows and how deep they extend within planetary interiors? are long-lived conundrums that aimed to be explored by designing the JUpiter Modelling Platform throughout the project JUMP.
To address the central question arise with JUMP, we designed the first mixed laboratory-numerical-observational platform to explore physical ingredients that govern the formation of zonal jets in the gas giant’s atmospheres. We deliver, in open access, a package of theoretic statistical tools to extract properties of Jupiter-like flows reproduced with the numerical and laboratory platform and observe from direct measurement in the planets. The theoretic statistical tools aim to disclose the dynamical mechanisms that lead to the formation of zonal jets. Using these tools, we show that zonal jets in planetary envelopes results from upscale transfer of kinetic energy from the small scale turbulent eddies up to the large scale jets. We show that this upscale transfer result of rapid planetary rotation in planet such as Jupiter and Saturn. Finally we evidence that large scale hydrodynamic features become zonal jets because of the curvature of the spherical planetary fluid layer. These successive dynamical parameters, namely the formation of turbulent eddies, rotation and spherical curvature, are responsible for the banding of Jupiter’s and Saturn’s atmospheres. In the Earth's atmosphere and oceans, jets are also present but they are so weak and meandering that they are virtually undetectable without some deep analysis of the flow. Nonetheless, jets formation in all planetary envelopes, of the Earth, gas giants and other exoplanets, are likely to result from the same planetary parameters.
These results, being obtained using a new climate model named DYNAMICO, we integrated today collaborative efforts of numerous scientific communities that aim to model and understand climate changes. Indeed, Jupiter and Saturn reference simulations that have been run to reproduce the planetary jets, can be considered as crucial tests for the new model DYNAMICO before it becomes a widespread model for the Earth’s atmosphere. Therefore, the next step will be to apply JUMP dynamical diagnostic to the most recent and future models of the Earth’s atmosphere and ocean.
