A modeling technique that describes the height dependence of meteorological parameters in the upper part of the atmospheric boundary layer by (z/z₀)(Ro)⁻¹, where z₀ is the surface roughness length and Ro = u_*/fz₀ is called the friction Rossby number, where f is the Coriolis parameter and u_* is the friction velocity. Other Rossby numbers are also used, always in the form of a velocity scale divided by the product of a length times the Coriolis parameter.