Sci-ber Text - 9th Grade

Earth's Energy - You Are My Sunshine!

Each day a remarkable amount of energy strikes Earth in the form of sunlight. The term insolation is used to refer to the amount of energy that arrives at Earth. When light energy strikes Earth it may be reflected back into space as light. It may be turned to heat energy which is eventually radiated back to space, or it may be captured by plants for a while. Examine the chart below to see where most of the sun's energy strikes Earth.

Activity:
Take a few minutes and collect your own insolation data. Follow the steps below.

Materials:

Thermometer
Paper and pencil
Clipboard
Sunny day

Procedure:

Under Trees	Brushy Area	Grass	Sidewalk	Road

Create a data table like the one above.
Go outside and measure the temperature at each location.
Answer the following questions:

Which area was the warmest?
Which was the coolest?
Why were some areas warmer than others?
Does the amount of sunlight striking the grass differ from the amount striking the road?
What happens to the energy striking trees, bushes and grass that doesn't happen to energy striking the sidewalk or road?

Click here for answers from one experiment.

Scientists tell us that on average, 6% of the sun's energy is reflected by the atmosphere, 25% is reflected by clouds, 4% is reflected from Earth's surface, 15% is absorbed by the atmosphere and 50% is directly or indirectly absorbed by Earth's surface (including plants).

Assignment:
Draw a diagram using the percentages in the previous paragraph to show the result of sunlight striking Earth. Use arrows to represent sunlight. Draw clouds and features on Earth's surface. Place labels to show the percentages of energy being absorbed or reflected. (Note: An Internet search with the phrase "Earth's Heat Budget" will provide ample help if you are having trouble. It might also help to research this idea in an Earth Science textbook that describes the heating of Earth's atmosphere. This topic is usually in or near units that have to do with weather.