Geostrophic turbulence: a Lagrangian perspective

That energy cascades to larger rather than smaller scales in two dimensions was proposed by Fjortoft and Batchelor in 1953. The simultaneous cascades of energy and enstrophy in 2-D and quasi-geostrophic flows were described by Kraichnan (1967) and Charney (1971), respectively. Rhines (1975) noted that Rossby waves are less effective at energy transfer, so the beta effect can effectively halt an inverse cascade. Lagrangian data provides a novel way of studying geostrophic turbulence, and has given indications of such phenomena in the atmosphere and ocean. However Lagrangian statistics can be difficult to interpret, and one must seek consistent indications among different measures. I'll review the relevant results and discuss the current state of understanding.