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.
The nth baroclinic Rossby radius is: In Earth's atmosphere, the ratio N/f0 is typically of order 100, so the Rossby radius is about 100 times the vertical scale height, H. For a vertical scale associated with the height of the tropopause, LR, 1 ≈ 1000 km, which is the predominant scale seen on weather charts for cyclones and anticyclones.
In the ocean, the Rossby radius varies dramatically with latitude.
[3] [4] The size of ocean eddies varies similarly; in low latitude regions, near the equator, eddies are much larger than in high latitude regions.
The associated dimensionless parameter is the Rossby number.