Living Things

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The Atmosphere
Table of Contents The Air Around You Air
Pressure Layers of the Atmosphere Energy in
Earths Atmosphere Heat Transfer Winds
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Composition of Earths Atmosphere

• Earths atmosphere consists of nitrogen, oxygen,
  carbon dioxide, water vapor, and other gasses as
  well as particles of liquids and solids.
• Nitrogen is the most abundant at approximately
  75 of the air but must be fixated through plants
  before animals can use it.
• Oxygen makes up roughly 21 of the atmosphere and
  is directly taken in by plants and animals.
• Carbon dioxide makes up about 1 of the
  atmosphere and is essential to plant life. Fuels
  like goal and gasoline release carbon dioxide
  into the atmosphere.
• Argon is an element that makes up 1 of the
  atmosphere.
• Trace elements and dust particles make up the
  remaining elements in the atmosphere.

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The Air Around You
Gases in the Air Which circle graph shows the
correct percentage of gases in the atmosphere?
How should each portion of the graph be labeled?
What would be a good title for the graph?
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http//www.nasa.gov/audience/foreducators/topnav/m
aterials/listbytype/What_is_Atmospheric_Pressure.h
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Air Pressure
Air Column The weight of the column of air above
you puts pressure on you. How does pressure from
air molecules keep you from being crushed?
Because air has mass, it also has other
properties including density and
pressure. Density amount of mass in a given
volume of air. Air pressure result of the
weight of a column of air pushing on an area.
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Measuring Air Pressure

• We use a barometer to measure air pressure.
  We measure air pressure in
  millibars.

Aneroid Barometer airtight metal chamber that is
sensitive to changes in air pressure
Mercury Barometer long glass tube open ended
while resting in a dish of mercury.
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Altitude Affecting Density Air Pressure
Altitude, or elevation, is the distance above sea
level. Air pressure decreases as altitude
increases. As air pressure decreases, so does its
density.
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Layers of the Atmospherehttp//www.brainpop.com/s
cience/earthsystem/earthsatmosphere/

• Scientists divide Earths atmosphere into four
  main layers classified according to changes in
  temperature.
• The four layers are the troposphere, the
  stratosphere, the mesosphere, and the
  thermosphere.

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Layers of the Atmosphere
Troposphere and Stratosphere Earth's weather
occurs in the troposphere. The stratosphere
contains the ozone layer. http//www.brainpop.com
/science/earthsystem/ozonelayer/
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Layers of the Atmosphere
Mesosphere and Thermosphere The mesosphere
protects Earths surface from being hit by most
meteoroids. In the thermosphere, the air is thin
and you cannot feel heat.
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Begin Your Homework

• Pages 428-431
• Altitude, Temperature, Observations for each
  layer of the atmosphere

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Layers of the Atmosphere Poster 2/7

• With your group, complete the Layers of the
  Atmosphere poster activity. This will be due at
  the end of class.
• If you finish early, begin working on the poster
  questions. What is not finished is homework.

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Radiation from the Sun
Energy travels to Earth as electromagnetic waves,
a form of energy that can move through the vacuum
of space. Most of the energy from the sun travels
to Earth in the form of visible light and
infrared radiation (longer wavelengths than red
light). A smaller amount arrives as ultraviolet
radiation (shorter wavelengths than violet
light). What are the types of electromagnetic
radiation in the diagram?
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Energy in Earths Atmosphere
Some sunlight is absorbed or reflected by the
atmosphere before it can reach the surface. The
rest of the wavelengths pass through the
atmosphere to the surface. wavelengths reach
Earths surface. Clouds act as mirrors
dispersing sunlight in all directions, scattering
the light back into space. Why is the sky blue?
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So why is the sky blue?

• A clear cloudless day-time sky is blue because
  molecules in the air scatter blue light from the
  sun more than they scatter red light. 
• When we look towards the sun at sunset, we see
  red and orange colors because the blue light has
  been scattered out and away from the line of
  sight.

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Energy in Earths Atmosphere
Materials at Earth's surface reflect different
amounts of energy. How would you use the higher
percentages below to show a bar graph?
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Energy in Earths Atmosphere
Complete each sentence with a word from the Word
Bank to learn what is happening to the energy at
Earth's surface and in the lower atmosphere.
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Greenhouse Effect in Earths Atmosphere
The greenhouse effect is a natural heat-trapping
process in which radiated heat is absorbed by
gases such as methane, water vapor, and carbon
dioxide. What is the sequence of events that
causes it to occur?
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Heat Transfer
Temperature is the average amount of energy of
motion of each particle of a substance. We use
thermometers to measure air temperature. The
metric temperature scale is Celsius where 00C is
freezing and 1000C is boiling. The Fahrenheit
scale is the US scale where 320C is the freezing
point and 2120F is boiling point.
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How is Heat Transferred?
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Winds

• Differences in air pressure cause the air to
  move. Wind is the movement of the air parallel to
  Earths surface, and always moves from an area of
  high pressure to an area of low pressure.
• Most differences in air pressure are caused by
  the unequal heating of the atmosphere. Air over
  heated surfaces expand and become less dense
  cool, more dense air flows underneath the warm,
  less dense air.
• We measure wind by looking at their direction and
  speed. Wind vanes measure direction (north,
  south, east, west) and anemometers measure wind
  speed.

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Local Winds
Winds that blow over short distances are called
local winds that are caused by the unequal
heating of Earths surface within a small area
(typically near bodies of water).
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Global Winds
Winds that blow steadily from specific directions
over long distances are global winds. Like local
winds global winds are created by the unequal
heating of Earths surface, but these occur over
a large area.
Where does the sun hit Earth most (M) and least
(L) directly?
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Global Winds
The Coriolis effect causes global winds to rotate
in a curve. Global winds in the Northern
hemisphere turn toward the right and in the
southern hemisphere curves toward the left.
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Global Wind Belts
The Coriolis effect and other factors combine to
produce a pattern of wind belts and calm areas
around Earth. Match the descriptions of the
global winds with their location on the globe.
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