Learning Lesson: How it is Currently Done

Overview

The constant pushing of molecules into each other is the reason we feel wind. As one molecule bumps into another, it transfers energy into the next molecule. This constant pushing on the ocean's surface also transfers energy to the water. This energy transfer is responsible for the motion of the world's ocean currents. Students will make their own ocean currents using straws and black pepper.

Procedure

1. Fill the baking pan with water to about one inch deep.
2. Position one student on each corner of the pan.
3. Sprinkle some black pepper in one corner of the baking pan.
4. At each corner position, have the students aim their straw along the side of the pan to their left.
5. Have each student gently blow through the straw across the top of the water and observe the motion of the pepper.

Discussion

Very quickly, the students will see a circulation develop in their pan and observe the pepper move in a clockwise motion. This clockwise motion is the same basic motion of the currents in the Northern Hemisphere.

The persistent high-pressure systems over both Atlantic and Pacific Oceans have created the clockwise motion of the currents in each region. Since wind moves in a clockwise motion in high pressure, the wind transfers some of its energy to the sea surface, generating currents.

In the Southern Hemisphere, the wind in high pressure systems moves in a counter-clockwise motion. As a result, the ocean's currents also move in a counter-clockwise direction.

You can also have the students at each corner blow across the water toward each other and observe what happens when opposing currents come together.