Baroclinic turbulence

Snapshot of the potential vorticity field in a simple two-layer model of baroclinic instability.

THE FORMATION OF MESOSCALE OCEAN EDDIES ON SCALES OF 30-300 KM is primarily driven by baroclinic instability, which releases the superabundant available potential energy stored in sloping isopycnals by basin-scale wind and buoyancy forcing. The details of the local shear and stratification profile can give rise to qualitatively distinct flavors of baroclinic instability, however. In particular, the presence of outcropping isopycnals at the base of the mixed layer — or, equivalently, a thermal wind shear — can have a strong impact on the necessary conditions for baroclinic instability and the resulting linear and nonlinear dynamics.

We are using satellite and hydrographic data, idealized numerical models, and instability analysis to elucidate the competing roles of planetary rotation, isopycnal tilting, and baroclinic shear on the formation and equilibration of mesoscale eddies in the ocean.

X. Xiao, K.S. Smith and S.R. Keating (In revision).
The effect of surface buoyancy gradients on oceanic Rossby wave propagation.  arXiv

A. Klocker, D.P. Marshall, S.R. Keating, and P.L.Read (2016)
A regime diagram for ocean geostrophic turbulence.
Q. J. Roy. Meteo. Soc. 142 (699): 2411-2417 link