Bellwork March 1, 2007Bellwork March 1, 2007

• Define the following words: Page 434Define the following words: Page 434– AtmosphereAtmosphere– TroposphereTroposphere– IonosphereIonosphere– Ultraviolet Radiation (U.V. Radiation)Ultraviolet Radiation (U.V. Radiation)– Ozone LayerOzone Layer– Chlorofluorocarbon (CFC’s)Chlorofluorocarbon (CFC’s)

Chapter 15:Chapter 15:Earth’s AtmosphereEarth’s Atmosphere

What is the Atmosphere?What is the Atmosphere?

• The atmosphere surrounds Earth and protects The atmosphere surrounds Earth and protects us by blocking out dangerous rays from the us by blocking out dangerous rays from the sun. sun.

• Is a mixture of gases that is layered and Is a mixture of gases that is layered and becomes thinner until it gradually reaches becomes thinner until it gradually reaches space.space.

• Insulates the Earth.Insulates the Earth.

• 78% Nitrogen78% Nitrogen

• 21% Oxygen21% Oxygen

• ~3% Water Vapor~3% Water Vapor

• 0.93% Argon0.93% Argon

• 0.04% Carbon Dioxide0.04% Carbon Dioxide

• trace amounts of other trace amounts of other gasesgases

Composition of Earth’s Atmosphere

Layers of the Layers of the AtmosphereAtmosphere

• Divided into five Divided into five different and different and distinct layers.distinct layers.

• Lower layers include Lower layers include the troposphere and the troposphere and stratospherestratosphere

• Upper layers are the Upper layers are the mesosphere, mesosphere, thermosphere and thermosphere and exosphere.exosphere.

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Lower LayersLower Layers

• TroposphereTroposphere

• StratosphereStratosphere

TroposphereTroposphere

• Where we study, eat, Where we study, eat, sleep, and play.sleep, and play.

• Lowest of Earth’s Lowest of Earth’s atmospheric layers.atmospheric layers.

• Contains 99% of the Contains 99% of the water vapor and 75% of water vapor and 75% of atmospheric gases.atmospheric gases.

• Layer in which clouds Layer in which clouds and weather occur.and weather occur.

Stratosphere Stratosphere

• ~ 10 km (6mi) to 50 km ~ 10 km (6mi) to 50 km (30mi) above Earth’s (30mi) above Earth’s SurfaceSurface

• Contains Ozone (OContains Ozone (O33) )

LayerLayer

• Temperature increases Temperature increases with altitude.with altitude.

Upper LayersUpper Layers

• MesosphereMesosphere

• ThermosphereThermosphere

• ExosphereExosphere

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MesosphereMesosphere

• From Stratosphere to 80 From Stratosphere to 80 km (50mi) above km (50mi) above surface.surface.

• Temperature decreases Temperature decreases with altitude.with altitude.

• Layer in which most Layer in which most meteors will burn up.meteors will burn up.

IonosphereIonosphere

• Layer of electrically Layer of electrically charged particles.charged particles.

• Contained within Contained within the mesosphere the mesosphere and thermosphere.and thermosphere.

• Allows radio waves Allows radio waves to travel across the to travel across the country.country.

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ThermosphereThermosphere

• Extends to from Extends to from mesosphere to 500kmmesosphere to 500km

• Contains the AurorasContains the Auroras• Thickest of the layersThickest of the layers• Temperature varies Temperature varies

greatly based on solar greatly based on solar energy. energy.

• Can heat up to 1,500°C Can heat up to 1,500°C or higher or higher

ExosphereExosphere

• Outermost layer Outermost layer extending to 800 km.extending to 800 km.

• Where satellites and Where satellites and shuttles orbit the Earth.shuttles orbit the Earth.

• Contains very few Contains very few moleculesmolecules

Ozone LayerOzone Layer

• Contained within the stratosphere.Contained within the stratosphere.

• It helps to protect us from the sun’s rays.It helps to protect us from the sun’s rays.

• Located 19-48 km above us.Located 19-48 km above us.

• Made of ozone (OMade of ozone (O33).).

• Destroyed by CFC’s.Destroyed by CFC’s.

• Hole in the ozone layer is increasing each Hole in the ozone layer is increasing each year.year.

• When the ozone layer disappears there will When the ozone layer disappears there will be more cases of skin cancer.be more cases of skin cancer.

Student’s Created

AssignmentAssignment

• Draw the layers of the atmosphere.Draw the layers of the atmosphere.

• Label each layer with the following:Label each layer with the following:– NameName

– Range (distance from Earth’s Surface)Range (distance from Earth’s Surface)

– CharacteristicsCharacteristics

– Temperature Range (Page 439)Temperature Range (Page 439)