# Beta-plane

From AMS Glossary

## beta-plane

The derivative of the Coriolis parameter with respect to latitude.

The beta-plane approximation, useful for the study of equatorial and midlatitude flow, assumes that the Coriolis parameter varies linearly with latitude. Explicitly, the Coriolis parameter is given approximately by in which

*y*is the meridional distance from some fixed latitude where the Coriolis parameter is*f*_{0}and β (from which the beta plane gets its name) is the meridional gradient of*f*at that fixed latitude.