Charney–Hasegawa–Mima equation

Summary

The Charney–Hasegawa–Mima equation is a nonlinear equation for a single stream function that appears both in geophysics and in plasma physics. In geophysics it is the equivalent-barotropic form of the quasi-geostrophic equations, a layer of finite deformation radius on a beta plane. In plasma physics it describes drift waves in a magnetised plasma with a density gradient. It is a basic model for Rossby waves, two-dimensional turbulence and zonal jets.