The Earth’s Atmosphere

The Layers of the Atmosphere

http://www.vtaide.com/png/atmosphere.htm

There are five layers of the atmosphere:•troposphere – weather occurs here, contains half of the atmosphere•stratosphere – planes fly here because it is a smooth ride, ozone layer is here•mesosphere – meteors burn up in this layer•thermosphere - known as the outer layer of the atmosphere, air is very thin•exosphere - this is where sattelites orbit the earth and some air particles are released into space

Image courtesy of:http://www.world-builders.org/lessons/less/les3/layers.html

Gases in the Atmosphere

The Earth’s atmosphere is made of nitrogen, oxygen, and other gases. The pie graph shows how much of each is in the air.

Hot Air Balloons

http://www.howstuffworks.com/hot-air-balloon.htm

Hot air balloons are are based on the basic principle that warmer air rises in cooler air. Hot air is lighter than cool air, because when air heats, the molecules spread apart. While a cubic foot of air normally weighs about 28 grams, if the air is heated by 100F, it weighs about 7 grams less. The reason hot air balloons are so huge is because about 65,000 cubic feet of hot air is needed to lift 1,000 pounds,

Image and more information on hot-air balloons can be found at:

http://www.howstuffworks.com/hot-air-balloon.htm

The Greenhouse Effect(it’s natural- somewhat)

The reason our planet is able to sustain life is because we have and atmosphere and something called the greenhouse effect. If you remember, when we studied the planets, those with no atmosphere were either really hot or really cold.

Image courtesy of:http://www.green-planet-solar-energy.com/mercury-the-planet.html

Mercury’s temperature varies from 200F to 800F even though it’s closest to the sun.

How Does it Work?

This is how the greenhouse effect works.• The sun’s rays reach the Earth and convert to

heat energy.• Some of this heat is absorbed by the surface. • Some of it returns back to space.• The atmosphere acts like a blanket, holding

the absorbed heat in so we don’t get too hot or too cold.

Image on next page courtesy of:http://www.weatherquestions.com/What_is_the_greenhouse_effect

.htm

Click on the picture to see an animation of the greenhouse effect.

Important Air Fact 1The surface of the earth heats unevenly.

Image courtesy of:http://www.boscobel.k12.wi.us/~schnrich/uneven_heating.htm

Important Air Fact 2

Hot air rises and cool air sinks.

Click the image to the right to see an animations of this.

Image courtesy of:http://www.revisionworld.com/country.php

Land and Sea Breezes

Uneven heating of air over land and water causes breezes near the shore. When the land is warmer than the water during the day, air above it rises, and a cool breeze blows in from the sea.

As the land cools off at night, air pressure over it increases, and a cool land breeze blows out to the sea.

Click on one the images to see an amimation of land and sea breezes.

Sea Breezes

Click on one the images to see an amimation of land and sea breezes.

Land Breezes

Images courtesy of:http://www.prh.noaa.gov/hnl/kids/activities.php

Our Experiments

We did several experiments to demonstrate the concepts covered in the slides you just viewed. On the following slides you will see pictures of each one, how it worked, and what we learned.

The Cup and Peanut

We filled a glass bowl with water and floated a packing peanut on the top. We then pushed down with a plastic cup and the peanut was pushed to the bottom of the bowl. Then we cut a hole in the cup and the peanut stayed floating.

We learned that air takes up space.

Newspaper and Ruler

We placed a ruler under newspaper to see if it was harder to push down than without the newspaper and it was.

We learned that air has weight.

The Two Bags and Candle

We put a candle under one of the two bags balanced at the right. The bag we placed a candle under rose.

We learned that hot air rises.

Temperatures of Different Surfaces

We used the device at right to measure the temperatures of:

• playground• ball field• basketball court• grass We found out that different

surfaces were different temperatures.

Hot and Cold Water

We added food coloring to both hot and cold water and poured into a glass bowl of tap water to see what happened. The hot water stayed toward the top and and cold water sunk to the bottom. We learned that hot air rises and cold air sinks. For pictures, click on the website below.

Experiment adapted from activity on the following website:http://www.prh.noaa.gov/hnl/kids/activities.php