GO IN DEPTH

# El Niño

### Introduction

You may have heard of El Niño before. But, do you know what it has to do with how the atmosphere and oceans affect one another? Use the resources on your El Niño student esheet to help you answer the questions on this sheet.

### Hot air over hot water activity

Materials

• Small, same sized cups (any material; e.g., ceramic, plastic, styrofoam)
• Hand-held mirrors
• Hot and cold water

Directions

1. Take two cups that are the same. They can be ceramic, plastic, styrofoam, whatever, as long as they're the same.
2. Fill one with cool water. Fill the other with hot water. (Not boiling, just good and hot.)
3. Place them on a table.
4. Hold each of your hands over one cup and feel the difference in the air above the water. (Don't actually touch the water. Just feel the air.) The hot water warms the air above it. The cool water doesn't. Now, imagine you fill your bathtub with hot water. Think about how warm and steamy the air in the bathroom gets. Now, imagine millions and millions of bathtubs-ful of hot water. All of that moist, hot air has to go somewhere. Scientists know that hot air rises and carries the moisture with it. Once the moisture gets into the air and starts to cool, rainclouds start to form.
5. Hold a small mirror over the cup of hot water for a few minutes. The moisture in the air should collect on the mirror, and, as it cools, form tiny droplets. Imagine the bathroom mirror after you fill the bathtub with hot water. The "water" on the mirror is caused by the water vapor in the air gathering and cooling. Now imagine the air over the hot water of the tropical Pacific Ocean.

### what is el niño?

What causes storms?

If water rising from the ocean and falling back down as precipitation is a common occurrence, why is El Niño different?

What causes the water to become warm?

### El Niño Events

Record how tradewinds affect El Niño.

### Upwelling and Thermocline

What is upwelling?

What is thermocline?

Draw diagrams of upwelling and thermocline.