 The Coriolis force is the deflection of objects observed in a rotating reference frame. If a person is standing in a fixed position in the northern hemisphere, an object moving away from him or her will tend to rotate towards the right in the northern hemisphere, and the left in the southern hemisphere is a result of the rotation of the earth. This effect is called the Coriolis force. The Coriolis force is very small because the rotation of the earth is very slow, 360 degrees in one day. However, the Coriolis force affects all air masses, whether they be giant hurricanes, such as Hurricane Katrina here, with a rotation towards the right and clockwise because it is in the northern hemisphere, cyclones, typhoons, as well as the large ocean gyres.