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Atmosphere in Motion
Lesson 1 Review
 How many levels of the Atmosphere?
 High Pressure is generally associated with what type of
weather? Stable or Unstable?
 What is Relative Humidity?
 Dew point temperature is the point at which
precipitation starts, True or False?
Radiation
 The heat energy of the Sun
reaches the Earth as
radiation or solar energy.
Radiation transfers heat by
means of heat waves.
 Radiation that reaches the
Earth is absorbed by land
and water surfaces.
Surface features influence
the amount of radiation
absorbed by the Earth.
Conduction
 The passage of energy, particularly
heat and electricity through an
object.
 Heated molecules move more
rapidly than cold molecules. Heat
is transferred from fast moving
molecules to slow moving
molecules until all are moving at
the same speed.
 A good example of conduction is a
stove heating a pan.
Convection
 The most efficient method of heating
the atmosphere. Air is first heated by
radiation and conduction.
 The air absorbs the heat energy.
Warm air is forced upward as cold air
flows in displacing the warm air.
 Convection currents cause constant
cold air for warm air until heat is
evenly distributed
Convection
 Convection currents cause a constant exchange of
cold air for warm air until heat is distributed evenly.
Advection
 The horizontal transfer of a heat, caused by air movement.
 When the wind blows, it is simply movement by or within
the local air mass. Advection is an important factor in the
global circulation of air.
Insolation
 The rate at which the Earth’s surface is heated by solar radiation.
 The amount received at any point on the Earth’s surface is dependent on
the angle that the Sun’s rays make with the horizon
 Greater in the equatorial zone than anywhere else on the Earth’s surface
due to the angle of incidence.
Heat Balance
 If there was no balance of heat
among the Earth, its atmosphere,
and space, the Earth would
become increasingly warmer.
 Of all the solar radiation arriving
at the top of the atmosphere, 31
percent is reflected into space by
clouds and atmospheric dust; 19
percent is absorbed directly into
the atmosphere; and 46 percent
reaches the Earth directly.
Wind
 When air is heated, it rises. This
occurs because the heat applied
to it has decreased its density to
the point where it is lighter in
weight than the surrounding air.
The surrounding cooler air
pushes the lighter, heated air
upward.
Coriolis Effect
 The Earth rotates on its axis in such a way that an observer
in space over the North Pole would see the Earth turning in
a counterclockwise direction.
The Pressure Gradient
 The high-pressure areas of the atmosphere are the
mountains, and the low-pressure areas are the valleys.
The wind flows from these high-pressure mountains
into the low-pressure valleys.
H
H
L
Local and Surface Air Movement
 The general circulation of air is complicated by the irregular
distribution of land and water areas.
 Different types of surfaces differ in the rate at which they absorb
heat from the Sun and transfer heat to the atmosphere.
 Some surfaces give off or
reflect a great amount of
heat.
Sand
• Rocks
• Plowed areas
• Barren land
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 Other surfaces tend to
retain heat.
Meadows
• Planted fields
• Water
•
Local and Surface Air Movement
 Moving air flowing around obstructions tends to break into
eddies.
The Jet Stream
 The jet stream is a narrow current of air, which moves around the Earth in
wavelike patterns. It is like a “river” of wind moving at a high rate of speed.
 The jet stream varies from about 100 to 400 miles wide and 1 to 3 miles
thick.
 Winds usually have a speed of 150 to 300 mph, but speeds of 450 mph have
been recorded. Its general motion is from west to east.
Quick Answer
Conduction is the passage of energy, particularly heat and
 ____________
electricity, through an object. An example is a frying pan
Convection is the process whereby air absorbs heat energy.
 ____________
Warm air is forced upward as cold air flows displace the warm
air.
 The horizontal transfer of a heat, caused by air movement is
Advection
called ________________.
A good example is fog.
Insolation
 ________________
is the rate at which the Earth’s surface is
heated by solar radiation.
A
B
A
B
Quick Answer
Coriolis Effect
 This effect is called the _________________
 The movement of the ball…is it real or apparent?
Apparent
 Different land surfaces retain or reflect solar energy (heat)
Sand
differently. ___________
is a good example of terrain that
reflects solar energy (heat).
 Water absorbs or reflects solar energy (heat). Absorbs
Jet
 This is called a _________
Stream
___________.
Summary
Atmosphere in Motion
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Conduction and Convection
Advection
Insolation
Coriolis Effect
Jet Stream