Quasi-two-dimensional turbulence on the polar beta-plane: laboratory experiments

Abstract

Results from a new series of experiments on turbulent flows decaying in a thin layer of water with a free surface in a rotating circular container are presented. The flows are generated electromagnetically using a regular array of permanent magnets. The Particle Image Velocimetry method is used to determine the velocity and vorticity fields in the flow. The experimental results demonstrate the formation of a polar vortex and jets perturbed by stationary Rossby waves in experiments with higher values of the beta parameter. Blocking events similar to those occurring in the Earth's atmosphere were observed in the laboratory flows. The Two-dimensional energy spectra of the flow demonstrate anisotropy in the space of the azimuthal and total wavenumbers. The One-dimensional energy spectra are characterized by a peak at the Rhines wavenumber.