Make Your Own El Niño in the Classroom
Materials:
Preparation:
Action! (Stage 1) - Have a student turn on the hairdryer (no heat needed) and direct the 'wind' it across the surface of the oil-topped water from the East to the West. Ask the class to describe what effect this has on the "warm" and "cold" water.
Comments: Note that the "warm" water piles up in the West as it is blown by the "trade winds" (hair dryer). This is the normal condition for the equatorial Pacific Ocean. Discuss the location of the warm water on the globe. Discuss what will happen to the air above the warm water in terms of how much moisture the air can hold. (Optional: Have them design an experiment to test the relative moisture holding capabilities of warm and cold air). You may notice that the sediment of the blue food dye moves upwards towards the surface at the east end (this will only happen if there is a sediment). This is upwelling which, in the Pacific Ocean, brings nutrient-rich bottom waters to the surface. Plankton feed on the nutrients, and in turn fish feed on the plankton, so these areas tend to be rich in fish and other sea life. Action! (Stage 2) - Have the student turn off the "trade winds" and ask the class to describe what happened when the trade winds stop. Comments: You may need to do this several times to observe the motion. The "warm" water pulses across the "ocean" from West to East, this pulse of water is the warm water that is the oceans part of the El Niño condition.
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Want to know more?
There is a lot of material available about El Niño's and La Niña's, or
send e-mail to Margaret Srinivasan for hard-copy
material. The educational CD-ROM, 'Visit to an Ocean Planet' which can be
ordered on-line, has a unit on El Niño's.
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