Standard 6, Objective 2

Earth Systems Standard 6, Objective 2

Title: El Nino in a Bowl

Description: Students model formation of an El Nino current in a pie pan.

Materials: clear glass pie plate, cold salty water with some red food coloring in it, warm fresh water, paper circles, turkey baster or large pipet (optional), plastic beakers, student page

Time Needed: 50 minutes

Background Knowledge: Students should know that El Nino is the name given to a certain combination of weather events that occur in a cyclic pattern. The interaction between prevailing winds and ocean water creates the effect. Students need to be aware that the coldest ocean water is most dense and stays at the bottom of the sea. It contains the most nutrients for living things. Living things need light and must live at the oceans surface. Typically, the prevailing winds blow surface water away from the coast and draw up colder nutrient rich water from the bottom. Schools of fish are attracted to the plankton that quickly grows there. During an El Nino year, the winds die or blow erratically and the water is not drawn up. Fish populations go down and weather patterns change as the pool of warmer water sits by the coast.

Procedures: 1. Read the procedures with students. If turkey basters are not being used, the student can pour the cold water from a beaker into the pie plate. 2. Students should see the red water collect right where their breath is blowing strongly. If students have difficulty seeing this it can be demonstrated on an overhead projector as long as you don’t turn on the light until you are ready. The light will heat up the water and it will mix. 3. Students should be encouraged to try the test several times and build a new ocean if they don’t succeed at first. 4. Discuss the results with students and give them time to answer the questions.

Scoring Guide 1. Students set up and perform experiment………………..4 2. Students collect and record data………………………….4 3. Students correctly answer analysis questions…………4 Answers: 1. it is densest 2. the wind moves the surface water away, pulling up the bottom water 3. the surface water continues to warm up 4. the cold water contains nutrients 5. air over warm water heats up and gathers moisture 6. when it hits land it may cool and precipitate 7. Wind water Title: El Nino in a Bowl name______

Purpose: To model the formation of an “El Nino” weather event.

Materials: clear glass pie plate, colored, cold salty water, warm fresh water, baster, plastic beakers

Procedure:

1. Add enough warm water to the pie plate to cover it in about 2 cm. of water. 2. Get a beaker of cold colored water. Draw up a baster full. 3. Place the tip of the baster on the bottom of the pie plate, under the warm water. 4. Slowly empty the baster into the dish. Keep adding cold water until it is as deep as the warm water. You should now have a two layer system. 5. A student should blow across the top surface near an edge of the pie plate. Have everyone else watch and observe what happens. Draw in the data what your plate looks like from the top. 6. If your two layer system has not mixed, try blowing TOWARD the edge of the dish from the middle. Record your findings on the data.

Data: Pie plate from the top:

Blowing away from near edge Blowing toward far edge analysis:

1. Why is the coldest, saltiest water on the bottom of the ocean?

2. What happens to the ocean as wind blows across the surface?

3. What happens to the ocean if the wind doesn’t blow?

4. Why is cold water coming to the surface important?

5. What happens to the air over warm ocean water?

6. What would that air mass do when it reaches land?

7. What can we do to stop “El Nino”?

8. Use arrows to show what happens to the ocean and atmosphere on a normal year:

Conclusion: