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The Coriolis Effect

Learner Objectives

By completing this lesson, the learner will:

Exploration

Consider current weather systems found world-wide. Describe any rotating patterns you see; are there any noticable differences between the northern and southern hemispheres? Follow other map links found at The Weather Channel Web Site to verify your generalizations. Make quick sketches to justify your position.

Demonstration

Part I:

The Coriolis effect can be easily and cheaply demonstrated with a circular piece of cardboard like that which comes with pizza. Pin or nail the cardboard so that it is allowed to rotate freely. Rotate it smoothly with one hand, and with the other hand draw a straight line from the center towards a particular fixed direction. You should notice a definite spiral to the line, despite the fact that the hand movement was linear. Repeat the demonstration by rotating the opposite direction; you should be able to draw some conclusions about the direction of apparent deflection in the northern hemisphere versus the southern hemisphere.

Teacher Directed Questions: What happened to the line as you rotated the cardboard? What happens to the line as you get further toward the edge? Use mathematics to describe what happened to the curve. (use trigonometry) What happens if you spin it fast or slow? Look at a satellite image, observe the pattern of air masses, and how does this explain the motion of the air massess? You can do the same demonstration as above with a chalkable globe. This is more expensive, but very realistic and an excellent way to firmly fix the concept of the Coriolis effect in your mind.

Part 2:

You can do the same demonstration as above with a chalkable globe. This is very realistic, more expensive, and an excellent way to firmly fix the concept of the Coriolis effect in your mind.

Teacher Directed Questions: Repeat the above. Is there any other way you can demonstrate the Coriolis effect? Essay Question-- Demonstrate that the Coriolis effect in the southern hemisphere is a mirror image of that in the north, that is, air masses curve to the left no matter which direction they move, including East-West.

Extensions

Investigate these links on Internet resource information regarding the Coriolis Effect.

Mathematically compute the effects of the Coriolis Effect using vector calculus.