# Richardson number

From AMS Glossary

(Redirected from Mixing efficiency)

## Richardson number

The dimensionless ratio of buoyant suppression of turbulence to shear generation of turbulence.

It is defined as where

*g*is the acceleration of gravity, β a representative vertical stability (commonly ∂θ/∂*z*, where θ is potential temperature), and ∂*u*/∂*z*is a characteristic vertical shear of the wind. It is used as a dynamic stability measure to determine if turbulence will exist.*See*gradient Richardson number, bulk Richardson number, critical Richardson number, flux Richardson number.