Jupiter's Zonal Jets and Turbulent Eddies: the Importance of Moist Convective Processes on a Global Scale

Abstract:

We present the first results from a general circulation model of Jupiter's weather layer that includes latent heat and moist convective processes on a global scale. This model uses the MITgcm as the dynamical core with additions relevant to Jupiter such as a 2-stream radiation scheme, vertical diffusion, internal heat flux, dry convective adjustment, MHD drag, a simple parametrization of NH3, NH4SH, and H2O cloud formation and subsidence, and, most recently latent heat and moist convective processes. The model has been developed primarily to examine the physical phenomena underlying the formation and maintenance of zonal jets on Jupiter, and the interactions between these and small-scale turbulent eddies, in particular how these depend on moist convective processes. Initial work without moist convection found a strong dependence of the strength and direction of the equatorial jet on the internal heat flux, including a prograde equatorial jet, but not at the speeds observed on the planet. We will also compare our model results against recent analyses of Jupiter's turbulence using kinetic energy spectra and structure functions, which show a clear upscale transfer of energy in the 3rd order structure function on scales larger than a few times the deformation radius.