The Atmosphere

1
The Atmosphere
2
Characteristics of the Atmosphere Terms
atmosphere, air pressure, troposphere,
stratosphere, mesosphere, thermosphere
3
Characteristics of the Atmosphere

• Describe the composition of Earths atmosphere.
• What does the name of each atmospheric layer
  mean?
• Why doesnt the thermosphere feel hot?

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The Composition of the Atmosphere

• The atmosphere is a mixture of gases that
  surrounds Earth.
• Makes conditions on Earth suitable for living
  things
• Gases keep the atmosphere on Earths surface warm
  enough for water to exist as a liquid, protects
  against dangerous radiation, prevents Earths
  surface from being hit by most meteoroids or
  chunks of rock from outer space.
• Gases
• Nitrogen 78
• Oxygen 21
• Other gases 1
• Water vapor lt1
• Solids
• Dust, volcanic ash, salt, dirt, smoke
• Liquids
• water

5
Atmospheric Pressure and Temperature

• As altitude increases, air pressure decreases
• Air pressure is strongest at Earths surface
  because more air is above you.
• Atmospheric composition affects air temperature
• Temperature differences result from the way solar
  energy is absorbed as it moves through the
  atmosphere
• High of gases that absorb solar energy warmer
• Less gases that absorb solar energy cooler

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Layers of the Atmosphere

• Based on temperature changes
• Troposphere layer in which we live contains
  almost all of the weather, carbon dioxide, water
  vapor, clouds, air pollution, and life-forms
• Stratosphere gases are layered and dont mix
  contains the ozone layer protects life by
  absorbing harmful UV radiation
• Mesosphere middle layer the coldest layer most
  meteoroids burn up here, producing meteoroid
  trails
• Thermosphere temperature increases does not
  feel hot outer most part of atmosphere no
  definite outer limit

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Summary

• Nitrogen and oxygen make up most of Earths
  atmosphere.
• Air pressure decreases as altitude increases.
• The composition of atmospheric layers affects
  their temperature.
• The troposphere is the lowest atmospheric layer.
  It is the layer in which we live.
• The stratosphere contains the ozone layer, which
  protects us from harmful radiation.
• The mesosphere is the coldest atmospheric layer.
  Meteoroids burn up in this layer.
• The thermosphere is the uppermost layer of the
  atmosphere.

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1 Quick Check

• Why does the temperature of different layers of
  the atmosphere vary?
• Because air temperature increases as altitude
  increases
• Because the amount of energy radiated from the
  sun varies
• Because of interference by humans
• Because of the composition of gases in each layer

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2 Quick Check

• What is the most abundant gas in the atmosphere?
• oxygen
• hydrogen
• nitrogen
• carbon dioxide

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3 Quick Check

• A major source of oxygen for the earths
  atmosphere is
• a. sea water.
• b. the sun.
• c. animals
• d. plants

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4 Quick Check

• The bottom layer of the atmosphere where almost
  all weather occurs, is the
• stratosphere
• troposphere
• thermosphere
• mesosphere

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5 Quick Check

• The ozone layer is located in the
• stratosphere
• troposphere
• thermosphere
• mesosphere

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Atmospheric HeatingTerms radiation, thermal
conduction, convection, global warming,
greenhouse effect
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Atmospheric Heating

• How do differences in air density cause
  convection currents?
• What is the radiation balance?
• What is the difference between the greenhouse
  effect and global warming?

15
Energy in the Atmosphere

• Radiation Energy transfer by waves
• Transfer of energy as electromagnetic waves
• Conduction Energy transfer by contact
• Transfer of thermal (heat) energy through
  material
• Convection energy transfer by circulation
• Transfer of thermal energy by circulation or
  movement of a gas or liquid.

16
Greenhouse Effect

• Greenhouse effect and life on earth process in
  which gases in the atmosphere, water vapor,
  carbon dioxide, absorb thermal energy and radiate
  it back to Earth.
• Atmosphere acts as greenhouse effect because the
  gases function like the glass walls and roof of a
  greenhouse, allowing solar energy to enter but
  prevents thermal energy from escaping.
• The amount of energy Earth receives everyday from
  the sun is balance by the amount of energy Earth
  reradiates into space.

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Greenhouse Gases and Global Warming

• Global warming is the gradual increase in average
  global temperature.
• Human activity, such as burning of fossil fuels,
  and deforestation, may be increasing the levels
  of greenhouse gases, such as carbon dioxide, in
  the atmosphere.
• If global temperatures continue to rise, it could
  disrupt global climate patterns

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Summary

• Energy from the sun is transferred through the
  atmosphere by radiation, thermal conduction, and
  convection.
• Radiation is energy transfer by electromagnetic
  waves. Thermal conduction is energy transfer by
  direct contact. Convection is energy transfer by
  circulation or movement of a gas or liquid.
• The greenhouse effect is Earths natural heating
  process. Increasing levels of greenhouse gases
  could cause global warming.

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1 Quick Check

• Which of the following is the best example of
  thermal conduction?
• A light bulb warming a lampshade
• An egg cooking in a frying pan
• Sitting by a fireplace getting warm by the fire
• Gases circulating in the atmosphere

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2 Quick Check

• What percentage of the solar energy that reaches
  the outer atmosphere is absorbed at the Earths
  surface?
• 20
• 30
• 50
• 70

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3 Quick Check

• By which method does most thermal energy in the
  atmosphere circulate?
• conduction
• convection
• advection
• radiation

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4 Quick Check

• The balance between incoming and outgoing energy
  is called
• The convection balance.
• The conduction balance.
• The greenhouse effect.
• The radiation balance.

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5 Quick Check

• As the sun heats the surface of the ocean, some
  of the water evaporates and enters the air. How
  does water vapor move in the atmosphere?
• by waves
• by clouds
• by conduction
• by convection

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6 Quick Check

• Energy transferred as electromagnetic waves is
  called
• thermal conduction.
• convection.
• radiation.
• convection current.

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7 Quick Check

• The process by which gases in the atmosphere
  absorb thermal energy and radiate it back to
  earth is called
• the thermal effect.
• global warming
• the greenhouse effect.
• radiation balance.

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Global Winds and Local Winds

• Terms wind, Coriolis effect, polar easterlies,
  westerlies, trade winds, jet stream

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Global Winds and Local Winds

• What causes wind?
• Why does sinking air cause areas of high
  pressure?
• Would there be winds if the Earths surface were
  the same temperature everywhere? Explain your
  answer.

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Why Air Moves

• Wind is caused by differences in air pressure.
• The greater the pressure difference, the faster
  the wind moves.
• Air rises at the equator and Sinks at the poles
• Pressure belts are found every 30
• The Coriolis effect is the apparent curving of
  the path of a moving object from an otherwise
  straight path due to the Earths rotation.

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Global Winds

• Polar Easterlies extend from the poles to 60
  latitude in both hemisphere moves from the poles
  carrying cold, sinking arctic air can carry
  moist air, producing snow and freezing weather.
• Westerlies found between 30 and 60 latitudes
  flow towards the poles west to east can carry
  moist air producing rain and snow.
• Trade Winds extends from 30 to the equator
  Early traders used trade winds to travel from
  Europe to America

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Global Winds

• The Doldrums where the trade winds from the
  Northern and Southern Hemispheres meet in an area
  around the equator very little wind
• The Horse Latitudes At 30 North and South weak
  windssinking air is very dry name due to horses
  thrown overboard to save drinking water.
• Jet Streams a narrow belt of strong winds that
  blow in the upper troposphere pilots use the jet
  stream to take advantage of the wind moving west
  to east.

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Local Winds

• Local winds are produced by local geographic
  features.
• Local winds move short distances and can blow
  from any direction.
• Local winds include sea and land breezes and
  mountain and valley breezes

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Sea and Land breezes

• During the day, air over the ocean is cooler and
  forms an area of high pressure. The cool air
  flows to the land, producing a land breeze.
• Air over the land is warmer. As warm air rises,
  it creates an area of low pressure.
• At night, air over the ocean is warmer. As the
  warm air rises, it forms an area of low pressure.
• Air over land is cooler and forms an area of high
  pressure. The cool air moves toward the ocean,
  producing a land breeze.

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Summary

• Winds blow from areas of high pressure to areas
  of low pressure.
• Pressure belts are found approximately every 30
  of latitude.
• The Coriolis effect causes wind to appear to
  curve as it moves across the Earths surface.
• Global winds include the polar easterlies, the
  westerlies, and the trade winds.
• Local winds include sea and land breezes and
  mountain and valley breezes.

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1 Quick Check

• Why does warm air rise and cold air sink?
• because warm air is less dense than cold air
• because warm air is more dense than cold air
• because cold air is less dense than warm air
• because warm air more pressure than cold air

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2 Quick Check

• In which wind belt is most of the United States
  located?
• westerlies
• northeast trade winds
• southeast trade winds
• doldrums

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3 Quick Check

• What causes wind?
• differences in air pressure
• differences in gravity
• differences in oxygen
• differences in the thermosphere

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4 Quick Check

• What causes differences in air pressure around
  the Earth?
• A. Warm air rises at the equator, and cold air
  sinks at the poles
• B. Warm air sinks at the equator, and cold air
  rises at the poles
• C. Warm air rises at the equator, and cold air
  rises at the poles.
• D. Cold air rises at the equator, and warm air
  sinks at the poles.

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5 Quick Check

• Air moves in large, circular patterns called
• pressure belts.
• convection currents.
• convection cells.
• trade winds.

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6 Quick Check

• Narrow belts of winds that can reach 400 km/h are
  called
• A, jet currents.
• b. jet streams.
• C. convection currents.
• D. convection streams.

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Air Pollution

• Terms air pollution, acid precipitation

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Primary Pollutants

• Primary pollutants are pollutants that are put
  directly into the air by humans or natural
  activity.
• Natural sources dust, sea salt, volcanic gases
  and ash, smole from forest fires, pollen.
• Human sources carbon monoxide, dust, smoke,
  chemicals from paint .

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Secondary Pollutants

• Pollutants that form when primary pollutants
  react with other primary pollutants
• Ozone
• Smog

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Sources of Human Caused Air Pollution

• A major source of air pollution is from
  transportation
• Industrial Air Pollution fossil fuels, oil
  refineries, chemical manufacturing plants,
  dry-cleaning busineses, furniture refinishers,
  auto body shops
• Indoor Air Pollution - Nitrogen oxides, Fungi and
  bacteria, Carbon monoxide, Solvents, Gasoline,
  Chlorine and ammonia, chemicals

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Acid Precipitation

• Precipitation such as rain, sleet, snow, hail,
  that contains acids from air pollution
• Effects of Acid precipitation on plants
• Effects of Acid precipitation on forests
• Acid precipitation and Aquatic ecosystems

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The Ozone Hole

• The ozone layer is thinning
• Caused by chemicals called CFCs
• Not able to block the suns harmful UV rays
• Damages genes
• Can cause skin cancer
• Cooperation to reduce the ozone hole
• CFCs can remain active 60 -120 years
• Will take many years for the ozone layer to
  completely recover

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Air Pollution and Human Health

• Daily exposure to small amounts of air pollution
  can cause serious health problems
• Children, elderly people
• People with asth ma
• allergies.
• Lung problems
• Heart problems
• Coughing
• Headaches
• Lung cancer

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Cleaning Up Air Pollution

• Much progress has been made with cleaning up air
  pollution
• Clean Air Act 1970
• EPA Environmental Protection Agency
• Controlling Air Pollution from Industry
• Allowance trading System- established amount of
  pollutants that companies can release
• Reducing Aair Pollution from Vehicles
• Hybrids, carpooling, public transportation,
  bikes, walking

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Quick Check

• 1. What are some sources of indoor pollution?
• 2. What is the ozone hole, and why does it form?
• 3. What are some effects of air pollution on
  human health?
• 4. What are some major sources of outside air
  pollution?
• 5. What are some ways to reduce air pollution?