Coriolis Effect on the spinning Earth

Trajectories inertial reference frame

Trajectories rotating reference frame

Coriolis Force Apparent force that deflects a path in the rotating frame of reference

Coriolis Force Trajectory is straight; observer turns beneath it

Rotation of the Earth Rotates West to East (counterclockwise as seen from above North pole) Poles on axis; equator farthest from axis Source: Earth and Moon Viewer, Copyright © 1989 by Jef Poskanzer.Earth and Moon Viewer

Coriolis Force on Earth Earth rotates to the East Source: Strahler and Strahler, Introducing Physical Geography, Trajectories deflect right in N hemisphere

Coriolis Force on Earth What happens in the Southern Hemisphere? Source: Strahler and Strahler, Introducing Physical Geography, Trajectories deflect left in S hemisphere

Coriolis Force on Earth The direction toilets and bathtubs drain on earth is not determined by the Coriolis force. They are to small and they drain too quickly for the Coriolis force to matter.

Global Circulation Equatorial air rises –Moisture precipitates –Air travels poleward –Diverted by Coriolis effect –Sinks, warms –Converges to equator

Global Circulation Polar air sinks –Diverted by Coriolis effect –Warms from ground, rises –Moisture precipitates –Returns to poles