ATMOSPH

ERE:

SECTION 1

- EART

H’S

ATMOSPH

ERE

WHAT IS THE ATMOSPHERE MADE OF????

• Mixture of :• Gases • Solids • Liquids

HOW WAS THE EARLY ATMOSPHERE MUCH DIFFERENT FROM TODAY?

• Volcanoes produced nitrogen and carbon dioxide, but little oxygen.

• More than 2 billion years ago simple organisms began producing oxygen.

• Eventually, oxygen formed an ozone layer that protected Earth from harmful rays

• Green plants and diverse life forms developed

GASES• Includes all of the gases in the

Atmosphere.• What type of mixture is the atmosphere? • Atmosphere is changing with the

introduction of pollutants: increasing human energy use is increasing the amount of Carbon Dioxide

• Pollutants mix with oxygen and other chemicals to form smog.

SOLIDS

Include dust, salt and pollen

LIQUIDS

Water droplets and Droplets from volcanoes

FIVE MAIN LAYERS OF THE ATMOSPHERE

• Lower Layers:• Troposphere : The layer where humans live. It extends about 10 km up, and contains most of the water vapor and gases. • Stratosphere: Extending from about 10 km to 50 km above Earth. It contains the ozone.

Upper Layers:Mesosphere: extends from 50 km to 85km and is the layer in which meteors are visible.

Thermosphere: Thickest part of the atmosphere; from 85 km to 500km. Has high temperatures.

Ionsphere: Layer of charged particles. Helps carry radio waves.

Exosphere: Outer layer of atmosphere in which the space shuttle flies, has very few molecules.

QUESTION TIME……………

• What is the layer of the atmosphere nearest to Earth’s surface?

• Which layer in the atmosphere is warmed by the heat from Earth’s surface?

• Describe temperatures in the thermosphere.

ATMOSPHERIC PRESSURE

• Molecules closer to the surface or more densely packed (at higher pressure) that those higher in the atmosphere because of the mass of gases pressing down from higher in the atmosphere.

ATMOSPHERIC PRESSURE

• As altitude increases, pressure decreases

• What happens when we climb a mountain? Why?

• What happens when we are swimming at the bottom of a deep pool? WHY?

ATMOSPHERIC PRESSURE

Observing the effects of Air pressure ……

Demonstration

Section 1: Enrichment Lab Sheet

TEMPERATURE IN ATMOSPHERIC LAYERS• Troposphere: warmed

primarily by the Earth’s surface; temperature decreases at altitude in creases

• Stratosphere: Temperature increase as as altitude increases--- mainly the upper portion because Ozone absorbs energy from the Sun.

• Mesosphere: Temperatures decrease with altitude.

• Thermosphere and Exosphere: 1st to receive the Sun’s rays------- extremely warm

OZONE• About 19km to 48 km above Earth in the

atmosphere, this layer of 2-atom-oxygen molecules (O3) protects the Earth from the Sun’s harmful ultraviolet radiation. • Life depends on it• Pollutants called chlorofluorocarbons (CFCs) are destroying the ozone layer.•Are used in refrigerators, air conditioners, aerosol sprays, and foam packaging.

The ozone layer has a large hole over Antarctica

DISCUSSION QUESTION

• What is the Ionosphere and where is it located?

• Where is air pressure the greatest? Why

• Why are chlorofluorocarbons harmful to the ozone?

• How does the atmosphere prevent some radiation from reaching Earth’s surface?