1. The Coriolis Force and Weather By Jing Jin February 23, 2006

2. Gaspard-Gustave Coriolis May 21, 1792- September 19, 1843 French mathematician, mechanical engineer, and scientist kinetic energy and work to rotating systems like waterwheels

3. The Coriolis Force Defined Arises from a noninertial frame (accelerated or rotating frame of reference) Causes deflection of a moving object from a straight line Fictitious force (~gravity, centrifugal force) A fluid assuming a parabolic shape as it is rotating

4. Measuring the Coriolis Force The Foucault pendulum consists of a heavy bob suspended from a bearing that allows it to turn in any direction as deflected by the Coriolis force  it appears to rotate. The precise rate of rotation depends on the latitude on the Earth where the bob is located.

5. Measuring the Coriolis Force The formula for the Coriolis acceleration is -2w x v, where v is the velocity of the particle in the rotating system and w is the angular velocity vector (which has magnitude equal to the rotation rate and points in the direction of the axis of rotation) of the rotating system. This is vector multiplications  magnitude of the Coriolis acceleration of the object will be proportional to the velocity of the object and also to the sine of the angle between the direction of movement of the object and the axis of rotation. The formula implies that the Coriolis acceleration is perpendicular both to the direction of the velocity of the moving mass and to the rotation axis. So in particular:  if the velocity (as always, in the rotating system) is zero, the Coriolis acceleration is zero  if the velocity is parallel to the rotation axis, the Coriolis acceleration is zero  if the velocity is straight (perpendicularly) inward to the axis, the acceleration will follow the direction of rotation  if the velocity is following the rotation, the acceleration will be (perpendicularly) outward from the axis

6. Effects on Weather Patterns meteorology and oceanography storms develop into cyclones: the Coriolis force deflects air parcels moving toward a center of lower pressure and causes them to swirl around the center of low pressure Induced rotation is clockwise in Southern Hemisphere and counterclockwise in Northern Hemisphere Cyclonic flow around a low pressure area. The blue arrows represent the pressure gradient force, the red arrows represent the Coriolis force.

7. Trajectory of Long-Distance Artillery Shells British naval gunners used Northern Hemisphere measurements of the Coriolis force for targeting in a conflict in the Southern Hemisphere But the Coriolis force acts in the opposite direction in the Southern Hemisphere Thus, the long-range shells were incorrectly aimed and missed their targets by miles.

8. Another Application A hypothetical situation: The circles are inertia circles. Air mass that is in motion would, if no other forces are present, turn full circle.

9. Works Cited Hawley, John F. and Katherine A. Holcomb. Foundations of Modern Cosmology. 2 nd ed. New York: Oxford University Press, 2005. “Coriolis Force.” Wikipedia. 23 February 2006.