Mountain torque

From Glossary of Meteorology

mountain torque

The torque about a given axis exerted on or by the earth's surface due to the force associated with a difference of pressure on two sides of a mountain.

For example, if the axis is the earth's polar axis and the air pressure is higher (level for level) on the west side of a mountain than on the east, there exists a mountain torque in the vicinity tending to speed up the earth's rotation.
See also frictional torque.