Download Atmosphere

Atmosphere
Composition of the Earth’s
Atmosphere
 The
atmosphere is a mixture of gases
with some suspended solids and
liquids.
 Nitrogen is the most common gas at
78% of the atmosphere.
 Oxygen is the next most common gas
at 21%
Composition of the Atmosphere
Earth’s Atmosphere
 Trace
amounts of other gases are
found that total only 1 %: water vapor,
Carbon Dioxide, Neon,
Methane,Ozone, Hydrogen, Helium
Other Planets’ Atmospheres

Earth’s Atmosphere
 Brown
Smog is made from nitrogen
oxides and hydrocarbons. (L.A. type)
 Gray Smog is from burning coal or oil
and contains sulfur oxides.
 Ozone is a pollutant when it is near the
ground. It is in most smogs.
Structure of the Atmosphere
 There
are five main layers in the
atmosphere.
The lowest layer is the Troposphere.
 The Stratosphere and Mesosphere are the
next highest layers.
 The Thermosphere and then the
Exosphere are the highest layers.

Layers of the Atmosphere
Layers of the Atmosphere
A. The Troposphere:
 1.Close to the ground
 2. Contains 75% of the Earth’s gases.
 3. Weather, clouds and smog occur at this
level.
 It ends at 10 Km above sea level.
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Layers of the Atmosphere
Layers Of the Atmosphere
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B. The Stratosphere
The ozone layer is within the stratosphere. It is a
thin layer of O3 which absorbs UV radiation.
C. The Mesosphere is the middle layer.
D. The Thermosphere contains the ionosphere.
The ionosphere is a layer of electrically charged
particles. Radio waves bounce off of it.
E. The Exosphere is the highest level before
space.
Atmospheric Pressure
 Gases
in the atmosphere have mass and
weight. Gravity pulls on the
molecules and causes pressure.
Pressure is force exerted on an area.
 P= F/A
 At sea level there are more molecules of air
above an area, so there is more pressure.

Units for Pressure
The S.I. Unit for pressure is Atmospheres
(Atm)
 The old unit used on T.V. is inches Hg
( Which is mercury)
 A metric unit is mm Hg ( millimeters)
 Another unit used is millibars (mb)
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Temperature in the Atmosphere
NAME
Exosphere
Height
(Km)
500 Km
Temperature
(Celcius)
600-1000
Thermosphere
200 - 500
0-600
Mesosphere
50 -150
-5 to 0
Stratosphere
10 - 50
-60 to -5
Troposphere
0 – 10
-60 to 50
The Ozone Layer
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20 Km above sea level
Ozone is 3 atoms of oxygen.
Located in the Stratosphere.
Ozone absorbs UV radiation from the sun.
ODP’s = Ozone Depleting Gases
CFC’s are ODP’s… Chlorofluorocarbons
CFC’s break the ozone down to oxygen molecules
Energy from the Sun
Radiation is the transfer of energy by
electromagnetic waves. EM waves
 30% of the radiation from the sun is
reflected off of the Earth.
 50% of the radiation is absorbed by Earth’s
surface.
 Clouds and the atmosphere absorb 20 % .

Energy Transfer in the
Atmosphere
Conduction – the transfer of energy when
molecules bump into one another.
 Air near the heated surface of the Earth is
heated by conduction.
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Energy Transfer…
Convection - the transfer of heat by the
flow of materials.
 Heated air is less dense and rises, cold air
sinks. This flow of air is called a
convection current.

The Water Cycle
The Hydrosphere = All of the water on the
Earth’s surface.
 97% of water is salt water, only 3% is fresh.
 67% of the fresh water is frozen at the polar
ice-caps , which are 2 miles thick in some
places.
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The Water Cycle

The Water Cycle
Water evaporates and becomes a gas.
 The evaporated water rises in the
atmosphere.
 As the water rises, it cools.
 As the gaseous water cool, it condenses to
form a liquid…clouds.
 Precipitation is next; the water falls as rain,
snow, sleet, or hail.
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Water Cycle
 Water
is recycled constantly.
 Water is purified through the water
cycle.
Movement of Air
Wind is caused by the uneven heating of the
Earth’s surface and atmosphere.
 Areas of temperature difference create areas
of pressure difference.
 Wind is the movement of air from areas of
high pressure to areas of low pressure.
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Movement of Air
 The
Coriolis Effect = the rotation of the
Earth shifts the wind to the right and north.
 The Jet streams = high altitude, strong
winds. The flow west to east in the U.S.
 The Jet stream has a major effect on
weather.
Movement of Air
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Movement of Air
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Sea Breezes – created during the day
because solar radiation warms the land
more than the water. It comes in from the
sea.
Movement of Air
Land Breezes – created at night, cold air
over the land forces up the warmer air over
the sea. The wind goes out to sea.
 Monsoon winds are seasonal winds that
occur in tropical areas. ( This creates a wet,
very rainy season.)
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Tools of Meteorology
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Anemometer
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Barometer
Psychrometer
Rain Gauge
UV Meter
Weather Satellite
Weather Balloon
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