The Atmosphere

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The Atmosphere

• Chapter 6 Notes

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Composition of the Atmosphere

• Atmosphere a mixture of gasses that surround the
  Earth
• Contains the oxygen you breathe and protects you
  from harmful rays from the sun.
• Water Vapor make up part of the atmosphere .
  When conditions change the water vapor can change
  to a liquid (rain) or solid (snow)

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Atmospheric Pressure

• The atmosphere is held around Earth by gravity.
• Gravity pulls gas molecules toward Earths
  surface which causes Air Pressure.
• Air Pressure the measure of the force with which
  air molecules push on a surface

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Air Pressure

• Air pressure is strongest on Earths surface.
• As altitude increases the pressure decreases.

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Atmospheric Temperature

• Differences in the temperature of the atmosphere
  result from the amount of solar energy absorbed.
• Some parts contain more gases which make them
  absorb more solar energy
• Other parts contain less gases which mean they
  are absorb less solar energy and are cooler.

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Layers of the Atmosphere
Draw this picture
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The First Layer

• Troposphere
• Lowest layer next to Earths surface
• Densest layer
• Contains 90 of the mass of the atmosphere
• The layer we live in
• Gases continuously mix in this layer
• Temperatures vary in this layer

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The Second Layer

• Stratosphere
• Gases are layered and do not mix in this layer
• The air is very thin and contains little moisture
• Lower stratosphere is very cold -60 degree temp.
  But temperatures rise as altitudes rise
• This layer is the home of the ozone layer, a
  protective layer that soaks of ultraviolet rays
  from the sun.

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stratosphere
troposphere
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The Third Layer

• Mesosphere
• The coldest layer
• Temperatures can be as low as -93 degrees Celsius
  at the top of the Mesosphere

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The Fourth Layer

• Thermosphere
• High temperatures 1000 degrees Celsius or higher
• It does not feel hot. The particles are moving
  very fast but they are not heating up.

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Ionosphere

• This occurs between the mesosphere and
  thermosphere.
• Gas particles become electrically charged
  particles called ions
• These ions radiate energy in the form of
  shimmering light called auroras

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Atmospheric Heating

• Energy from the sun is absorbed by the
  atmosphere, land, and water and is changed into
  thermal energy.

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Heat TransferConduction, Convection and
Radiation
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To Make Foldable
1. On the short side of the paper, fold it down
an inch. 2. Now fold it in half, hamburger
style. 3. Now fold it in 1/3.
Outside of Foldable
Inside of Foldable
Conduction
Convection
Radiation
Examples Definition
Examples Definition
Examples Definition
Heat Transfer
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Thermal Energy Transfer

• Thermal energy transfer is heat moving from a
  warmer object to a cooler object. This is known
  as thermal energy transfer.

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How is Heat Transferred?

• There are THREE ways heat can move.
• Conduction
• Convection
• Radiation

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CONDUCTION

• Heat is transferred from one particle of matter
  to another in an object.
• Conduction CONTACT/ TOUCH

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Have you ever

• Touched a metal spoon sitting in a pan of boiling
  water only to be surprised by HOW hot it is??

Think back to what you know about metals and
nonmetals. What conducts heat better, metal or
nonmetal? Why?
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Example of Conduction

• Think of a metal spoon in a pot of water being
  heated.
• The fast-moving particles of the fire collide
  with the slow-moving particles of the cool pot.
• Because of these collisions, the slower particles
  move faster and heat is transferred.
• Then the particles of the pot collide with the
  particles in the water, which collide with the
  particles at one end of the spoon.
• As the particles move faster, the metal spoon
  gets hotter. This process of conduction is
  repeated all along the metal until the entire
  spoon is hot.

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EXAMPLE OF CONDUCTION

• A piece of cheese melts as heat is transferred
  from the meat to the cheese (Contact)

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CONVECTION

• Convection is the movement that transfers heat
  within fluids and air (gas)
• Heat is transferred by currents within the fluid
  or gas
• Convection VENTS (through air and liquid
  particles)
• Convection moves in
• a circular pattern

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Examples of Convection

• Have you ever noticed that the air near the
  ceiling is warmer than the air near the floor? Or
  that water in a pool is cooler at the deep end?
• Examples air movement in a home, pot of heating
  water.
• Pick one of these examples and draw the circular
  pattern in your notes.

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Explaining Convection

• Convection currents cause the cooler breezes you
  experience by a large body of water.
• These currents also cause the movement of magma
  within the earth.

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RADIATION

• Radiation is the transfer of energy by
  electromagnetic waves
• Radiation does NOT require matter to transfer
  thermal energy
• Radiation Radiates (heat escaping the sun)

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Radiation May Come From Other Sources

• Have you ever sat too close to a campfire while
  cooking marshmallows? Youre enjoying the warmth
  .. only to notice that your skin is really warm?

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Examples of RADIATION

1. Fire
2. Heat Lamps
3. Sun

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Radiation Energy Transfer by Waves

• Radiation is the transfer of energy as
  electromagnetic waves.
• The sun radiates huge amounts of energy But Earth
  only receives two-billionths of this energy
• Energy from the sun drives the weather and makes
  Earth habitable.

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Conduction Energy Transfer by Contact

• Thermal Conduction is the transfer of energy
  through a material
• Always transferred from warm to cold areas
• Occurs when air molecules come in direct contact
  with the warm surface of the Earth.

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Convection Energy Transfer by Circulation

• Convection is the transfer of thermal energy by
  the circulation or movement of a liquid or gas
• Most thermal energy is transferred through
  convection

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Convection

• Example, as air is heated, it becomes less dense
  and rises. Cool air is denser, so it sinks. As
  the cool air sinks, it pushes the warm air up.
  The cool air is eventually heated by the Earth's
  surface and begins to rise again. This is called
  a convection current

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Greenhouse Effect

• 70 of the radiation that enters the atmosphere
  is absorbed by the clouds or by the Earths
  surface.
• The energy is converted into thermal energy.

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Greenhouse Effect

• The greenhouse effect is the process by which the
  gases in the atmosphere absorb thermal energy and
  radiate it back to the Earth.
• Acts much like the glass walls and roof in a
  greenhouse.

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Radiation Balance

• In order for the Earth to remain livable, the
  amount of radiation coming into the Earth must
  equal the amount of thermal energy the Earth
  releases into space.
• There must be BALANCE!!

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Global Warming

• Global warming is the gradual increase in average
  global temperature
• Causes the icecaps to start to melt
• Possible causes
• Too many greenhouse gases
• Human activity
• People are not doing their part to keep the Earth
  clean and safe
• Using too many Fossil Fuels!!

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Global Winds and Local Winds

• Wind the movement of air caused by differences
  in air pressure
• The greater the pressure, the faster the wind
  moves.
• Ex Hurricanes

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Hurricane Andrew
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Air Rises at the Equator and Sinks at the Poles

• Differences in air pressure are caused by unequal
  heating of the Earth.

Equator Poles
Receives more solar energy Air is warmer and less dense The air rises creating an area of low pressure The warm air flows towards the poles Receives the warm air, which becomes colder and denser The cold air sinks creating an area of high pressure The cold air then flows back towards the equator.
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Pressure belts are found every 30º

• Air travels in many large circular patterns
  called convection cells.
• Convection cells are separated by pressure belts
  that include bands of high and low pressure every
  30 of latitude

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Coriolis Effect

• The Coriolis effect is the apparent curving
  motion of winds and ocean currents due to Earths
  rotation.
• Northern Hemisphere the winds traveling north
  curve to the east and winds traveling to the
  south curve to the west

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Global Winds

• The combination of convection cells found at
  every 30º of latitude and the Coriolis effect
  produces patterns of air circulation called
  global winds.

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Polar Easterlies

• The wind belts that extend from the poles to 60
  latitude in both hemispheres are called the polar
  easterlies.
• They are formed as the cold sinking air moves
  from the poles toward 60 north and 60 south
  latitude.
• The polar easterlies are responsible for bringing
  cold arctic air over the United States.

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Prevailing Westerlies

• The wind belts found between 30 and 60 latitude
  in both hemispheres are called the westerlies.
• The westerlies flow towards the poles from west
  to east
• The westerlies are responsible for bringing moist
  air to the United States.

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Trade Winds

• The winds that blow from 30 latitude almost to
  the equator are called trade winds.
• The Coriolis effect causes the trade winds to
  curve west in the Northern Hemisphere and east in
  the Southern Hemisphere
• Early traders used these winds to sail from
  Europe to the Americas.

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The Doldrums

• The trade winds meet in an area around the
  equator called the doldrums.
• There is very little wind because there is very
  low pressure.
• This is why it is called the doldrums.

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Horse Latitudes

• At about 30 north and 30 south latitude,
  sinking air creates an area of high pressure. The
  winds are weak in this area called the horse
  latitudes.
• Legend says that sailors would get stuck in this
  windless area. Instead of wasting drinking water
  they would through the horses overboard.
• Most of the Earths deserts are located at this
  latitude.

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Jet Streams Atmospheric Conveyor Belts

• Jet Streams are a narrow belt of strong winds
  that blow in the upper troposphere.
• Can reach maximum speeds of 400km/h
• Do not follow regular patterns
• Important for pilots and meteorologists.

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Local Winds

• Local winds move short distances and can blow
  from any direction.
• Shorelines or mountains can create local wind
  patterns

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• Sea Breeze- 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 sea
  breeze.

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• Land Breeze- at night air over the land is cooler
  and forms an area of high pressure. The cooler
  air moves toward the ocean producing a land
  breeze.

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Sea and Land Breezes
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• Mountain Breeze- at night air along the mountain
  slopes cool . This cool air moves down the slopes
  into the valley producing a mountain breeze.

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• Valley Breeze during the day, the sun warms the
  air along the mountain slopes. This warm air
  rises up the mountain creating a valley breeze.

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Air Pollution

• In December 1952, one of London's dreaded "pea
  souper" fogs settled on the city. But this was no
  ordinary fogit was thick with coal smoke and air
  pollution. It burned people's lungs, and the sky
  grew so dark that people could not see their
  hands in front of their faces. When the fog
  lifted four days later, thousands of people were
  dead!

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Air Pollution

• Air Pollution is the contamination of the
  atmosphere by the introduction of pollution from
  human and natural sources
• Air pollution is common in many places
• Must be reduced

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Primary Pollutants

• Pollutants that are put directly into the air by
  humans or natural activity are primary pollutants
• Ex dust, sea salt, volcanic gases and ash, smoke
  for forest fires, and pollen, carbon monoxide,
  dust, smoke, vehicle exhaust

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Primary Pollutants
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Secondary Pollutants

• Pollutants that form when primary pollutants
  react with other primary pollutants or with
  naturally occurring substances are secondary
  pollutants.
• Ex ozone and smog

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Formation of Smog

• Smog forms when ozone and vehicle exhaust react
  with sunlight
• Pollution controls have been put in effect in
  some places to control the amount of pollution
  and reduce the amount of smog.

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Sources of human caused air pollution

• Transportation is a major cause of air pollution
• It causes10-20 of the pollution in the United
  States
• Vehicle exhaust contains nitrogen oxide which
  contributes to smog

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Industrial Air Pollution

• Industrial plants and electrical power plants
  burn fossil fuels to produce energy.
• Oil refineries, chemical manufacturing plants,
  dry-cleaning businesses, furniture refinishers,
  and auto body shops all produce air pollution.

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Indoor Air Pollution
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Indoor Air Pollution

• Indoor air pollution can be reduced by
• Ventilation-mixing of indoor air with outdoor air
• Reduce indoor air pollution by limiting the use
  of chemical solvents and cleaners

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Acid Precipitation

• Precipitation such as rain, sleet, or snow that
  contains acids from air pollution is called acid
  precipitation.
• The burning of fossil fuels releases sulfur
  dioxide and nitrogen oxide into the atmosphere.
• They combine with water in the atmosphere to form
  sulfuric acid and nitric acid.

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Acid Precipitation and Plants

• Soil naturally has acid.
• Acid precipitation can cause the soil acidity to
  increase
• This is called acidification.
• When acidification occurs
• Some nutrients are dissolved
• Aluminum and toxic metals are released and
  absorbed by the roots of plants

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The Effects of Acid Precipitation on Forests

• Eastern Europe Poland
• Forests have been severely damaged by acid
  precipitation

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Acid Precipitation and Aquatic Ecosystems

• If the amount of acid increases in the water then
  the plants, fish, and other organisms may die.
• A rapid change in a body of waters acidity is
  called acid shock.
• Some communities use powered lime a base to
  reduce the amount of acid in the water.

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The Ozone Hole

• 1985 scientists reported that the ozone layer
  over Antarctic regions was thinning.
• Chemicals called CFC were causing the ozone to
  break down into oxygen

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The Ozone Hole

• 1987 action was taken to solve the ozone problem
• A ban of all CFC chemicals was created
• CFC alternatives were developed
• CFC chemicals take 60 to 120 years to quit
  working. Therefore even with the ban CFCs used
  30 years ago are still harming the ozone now!!!

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Air Pollution and Human Health
Short Term Effects Long Term Effects
Headache Nausea Irritation to eyes, nose, and throat Coughing Upper respiratory infection Worsening of asthma and emphysema Emphysema Lung cancer Permanent lung damage Heart disease
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Cleaning up air pollution

• 1970 the United States Clean Air Act was passed
  by Congress.
• This act gives the Environmental Protection
  Agency the authority to control the amount of
  pollutants that can be released from any source.
• The EPA checks air quality.
• The Clean Air Act was strengthened in 1990.

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Air Pollution from Industry

• The Clean Air Act requires factories to use
  scrubbers.
• A scrubber is a device that is used to remove
  some pollutants before they are released by
  smokestacks.

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The Allowance Trading System

• The Allowance Trading System the EPA gives
  allowances for the amount of pollutants that
  companies can release.
• If a company goes over--- they pay fines.
• If a company is under they can sell there extra
  allowances to other businesses.

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Reducing Air Pollution from Vehicles

• The EPA requires car makers to meet certain
  criteria for exhaust.
• Use of cleaner fuels and more efficient engines
• Hybrids, carpools, public transportation, or
  biking and walking all reduce air pollution.