Two-layer quasi-geostrophic (QG) turbulence has been studied as an idealization for atmospheric and oceanic eddies. It is simple in the sense that fast waves are filtered out, thereby allowing for efficient numerical integrations and parameter space exploration. Yet, key features of geostrophically balanced motion with stratification (represented by two vertical modes) are built into the QG formulations.

On this subject, the overall theme is to better understand the scales and transport of baroclinc eddies in the turbulent flows. The tool we use is an open-source, spectral PDE solver, called Dedalus.

In the examples below, we can see the well known result that, as the strength of beta (i.e. meridional gradient of the background rotation rate) increases, eddies transition from being largely isotropic to zonally elongated, with banded zonal jets (5 jets in this case) emerging in the bottom right panel. We are examining the dependence of this transition on environmental parameters (i.e. drag strength and beta) as well as the amount of dissipation that is associated with the jets.

Images below offer examples of zonal jets emerged in turbulent flows. Left is a new image of Jupiter from NASA's James Webb Space Telescope. Right is the AVISO-derived, 10-year anomalies of surface geostrophic current from Maximenko et al. (2005). Multiple zonal jets are ubiquitous in both Pacific and Atlantic basins.