Earth’s Atmosphere

Take a Walk Through the Book

• What looks interesting? • What are you looking forward to

learning about?• What is something that you already

know about?• Find a picture that looks interesting.

Read the caption and write the page # down.

1.1 The Big Concept

•Earth’s atmosphere is a blanket of gases that supports and protects life.

Little Concepts• The atmosphere makes life on Earth

possible.• Natural processes modify the

atmosphere.

Remember our 4 spheres• Atmosphere•Hydrosphere• Biosphere•Geosphere

What is the Atmosphere?• Atmosphere: • Is a whole layer of air that surrounds

Earth.

Earth’s Atmosphere• Gases keep the

Earth warm.• Transport energy to

different regions of the planet.

• Absorb and deflect radiation from the sun.

Density• Density• The amount of

mass in a given space.

• Density is a key concept to our atmosphere.

Altitude• The distance above

sea level.• In 1862 two

balloonists reached an altitude of 8.8Km (5.5 miles)

• One passed out and one barely brought their balloon down.

• They found that the air gets thinner as altitude increases.

Altitude and Density• The higher up you go, the less air

particles there are.• Where jets fly there is 1/10th the air

molecules as at sea level.

Where Does it End?• There is no real “end” to the

atmosphere. (According to our book)• The gases just keep getting less and

less dense as you move away from Earth.

• At 500Km (300mi) you are considered in outer space.

• 99% of the atmosphere’s mass is in the lowest 20 miles of the atmosphere.

What is the Atmosphere Made up of?

• Gas Molecules• Dust• Sea Salt• Water Molecules

Gases in the Atmosphere• Put these gases in order from greatest to

least and give them a percentage of how much of them are in our atmosphere:

• Argon• Water Vapor• Oxygen• Other Elements• Nitrogen• Carbon Dioxide

Which Gases?Gas

• Nitrogen• Oxygen• Argon

• Carbon Dioxide• Other Elements• Water Vapor

Percent• 78.08• 20.94• 0.93• 0.04• 0.01• 0-4*

Natural Changes• Every day you breath in about 3,000

gallons of air. – About as much as it takes to fill a school

bus.• Cycle:• A process that continues over and

over.

Three Important Cycles

•Water Cycle•Nitrogen Cycle•Carbon Cycle

The Water Cycle• The water cycle has three main phases.• Evaporation- water is heated and

molecules rise up into the atmosphere.• Condensation- those same water

molecules cool down and start to cling together.

• Precipitation- As the water molecules cling together, they are too heavy for the air to hold and they fall back to Earth.

The Water Cycle

The Nitrogen Cycle• There are three main steps.• Animals remove nitrogen from the air

and transform it into waste, that is deposited back to the soil.

• Plants die and decay and the nitrogen in their system returns to the earth.

• The soil slowly releases nitrogen gas back into the atmosphere.

The Nitrogen Cycle

The Carbon Cycle• Animals inhale oxygen and exhale

carbon dioxide and water vapor.• Plants take in carbon dioxide and

release oxygen.

The Carbon Cycle

Sudden Changes in Our Atmosphere

• We can have sudden, natural events that change the composition of our atmosphere.

• Volcanoes- The sulfur, carbon dioxide, and ash may cloud the air for long times.

Sudden Changes in Our Atmosphere

• Forest Fires- When trees burn, the carbon in them moves into the atmosphere.

• Other Storms- Wind, water and drought can loosen soil. Wind storms add particles of dirt to the air.

Bibliography• http://www.bing.com/images/search?q=Earth's+atmosphere&view=detail&id=C6717111B2EA4B2C406CE78629033CEB

B6BA6A76&first=1&FORM=IDFRIR• http://wshm.bimedia.net/WebStuff/Air_vs._Altitude.jpg• http://upload.wikimedia.org/wikipedia/commons/b/b1/Minnesota_population_map_cropped.png• http://www.enchantedlearning.com/wgifs/Watercycle.GIF• http://eo.ucar.edu/kids/green/images/carboncycle_sm.jpg