# Does the Sun Influence the Temperature of the Earth?

### Guiding Questions

1. Does the sun influence the temperature of the earth?

2. How can you prove the sun influences or does not influence the temperature of earth surfaces?

3. Does the sun have the same influence on all earth surfaces? Why or why not?

## Objectives

#### Concepts:

The sun's energy heats up the earth.

#### Principles:

• Different surfaces of the earth absorb different amounts of the sun's energy.

• The more of the sun's energy a particular surface absorbs, the hotter it becomes.

• An experiment can be conducted to see if the sun's energy influences the temperature of the earth.

#### Facts:

• If you have a generalization or hypothesis, you can come up with a test to see if it is true or valid. For example, we will do a test or experiment to see if the sun does affect the temperature of the earth.

• Darker and denser earth surfaces absorb more of the sun's energy and so become hotter.

• Lighter-colored and less dense earth surfaces absorb less light and so are cooler than darker surfaces.

• By measuring and documenting the temperature of different earth surfaces, we can prove that darker surfaces absorb more of the sun's energy, because their temperatures are higher than those of lighter surfaces.

#### Skills

• Making Observations
• Making Measurements
• Recording Data
• Making Interpretations of Data
• Forming a Generalizations and Hypothesis
• Drawing Conclusions

### Materials

2. Pencil or Crayon
3. Thermometer

### Room Preparation

No special requirements. Need to be able to go outside and take temperatures of a variety of earth surfaces such as dark pavement or blacktop, concrete, bare ground, grass, shaded area, water or snow. Be sure to do experiment on a sunny and calm day so that clouds and winds do not impact temperature readings of surfaces.

### Safety Precautions

Be careful if you take temperature readings in areas near traffic.

## Procedures and Activity

### Introduction

1. Does the sun influence the temperature of the earth?
• Share ideas.
• Have students give proof or examples of what they believe.
• Help group come up with a general statement they believe in and a hypothesis
2. How can you prove the sun influences or does not influence the temperature of earth surfaces? Discuss ways to conduct an experiment or test to see if the temperature of the earth is influenced by the sun. Some of these ideas can be used as "Extension Ideas" or further experiments.

### Activity

1. Give each student or pair a thermometer and the age-appropriate handout.

• Go over where the students may go to take the temperature of different surfaces.

• Remind them to let a thermometer sit on a surface for three or four minutes before they take a reading and to let a thermometer get back down to air temperature before taking the reading of another surface.

• Go over how to describe the "outdoor conditions" of the day. Briefly talk about whether the conditions might change our experiment and findings. Would a cloudy and windy day change things?

• Talk about "Location" column on handout #2. Help students see that in order to replicate or try their experiment again, they need to know just where the surfaces were that they tested the first time. So, we need to try and describe where we took a thermometer reading in the grass, shade, etc. Handout #1 does not include location description of test sites.

2. Review how to accurately read a thermometer and record data on the handout.

• Share why accuracy is important for scientific experiments and for testing a hypothesis.

3. Have students go out and record temperatures of various earth surfaces listed on the handout.

## Closing - Original Questions

1. Does the sun influence the temperature of the earth?
2. How can you prove the sun influences or does not influence the temperature of earth surfaces?
3. Does the sun have the same influence on all earth surfaces? Why or why not?

## Evaluation

Listen as students give their ideas and share experiment facts to answer the questions. Look for evidence that they understand that the earth's surfaces absorb or take in heat energy from the sun and that different surfaces absorb different amounts of heat. Write on the chalkboard the various surfaces tested. Write down the temperature each person or pair found for each surface. Help students draw some conclusions from looking at and thinking about their facts and findings. For example, shaded areas are protected from the sun and so the surface is not as hot as blacktop or pavement that is dark in color and fully exposed to the sunlight. Go over what a hypothesis is, how you can devise a test or experiment to see if your hypothesis is true, and basic rules about being accurate about your tests, observations, and recording of findings.

## Extension Ideas

1. Talk about controlling variables in experiments. Share ideas about how temperature readings for surfaces could be altered or changed by doing the experiment on a cloudy, windy, or cloudy and windy day.

2. Repeat experiment and recording temperature findings on days with different variables like a sunny but windy day, a cloudy and calm day, and a cloudy and windy day. Compare data from different types of days and come to some conclusions. Form a hypothesis and design and carry out an experiment to test it.

3. Who cares about the varying and changing temperature of earth surfaces? Talk about people who farm, deal with water and air pollution, lay asphalt or concrete, work outdoors.

4. How does the sun's warming of the earth's surfaces impact us and our activities? Talk about swimming and water sports, winter skiing and snow sports, walking on pavement or sandy beaches, breathing on humid and hot days, sitting in a parked and closed-window car (concern for animals), warming ourselves on a winter day...

5. Have students explore and research solar energy, what it is and how it works.

6. Explore Images and Animations Illustrating Convection from the Jet Propulsion Laboratory

7. Look over other activities from CAPS: Convection in Our Atmosphere, Reading a Thermometer, Keeping a Daily Weather Log, What Is Heat Transfer?, and What is Temperature?

## Careers Related to Lesson Topic

• Construction Worker
• Environmental Engineer
• Environmentalist
• Farmer
• Meteorologist
• Tour, Weather Underground at University of Michigan's Atmospheric, Oceanic, and Space Sciences Department
• TV or Radio Weather Reporter

Let us know what you think!

Mark Palmer
University of Oklahoma
Center for Analysis and Prediction of Storms
(405)-325-6079
mpalmer@ou.edu

## Prerequisite Vocabulary

Absorb
When something takes in or sucks up something. Examples are a sponge sucking up water or a surface of the earth taking in heat from the sun.

Energy
Useable power; in this lesson we are talking about the sun and its heat energy.

Hypothesis
An assumption or idea about something that we can do experiments or tests on to see if it is true or valid.

Sun
The luminous body in the sky that the earth rotates around that gives off heat and light.

Updated 18 Jan 01