Rossby radius of deformation

In atmospheric dynamics and physical oceanography, the Rossby radius of deformation is the length scale at which rotational effects become as important as buoyancy or gravity wave effects in the evolution of the flow about some disturbance.

For a barotropic ocean:

$L_R \equiv \frac{(gD)^{1/2}}{f_0}$, where $\,g$ is the gravitational acceleration, $\,D$ is the water depth, and $\,f_{o}$ is the Coriolis parameter at the reference latitude.

For baroclinic flow:

$L_R \equiv \frac{NH}{f_0}$, where $\,N$ is the Brunt–Väisälä frequency and $\,H$ is the scale height.

The associated dimensionless parameter is the Rossby number. Both are named in honor of Carl-Gustav Rossby.

Chelton et al. evaluated its geographic variability.