Pressure Gradient Force

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Pressure Gradient Force directed from high to
low pressure

• The change in pressure measured across a
  distance is called a "pressure gradient".

In one complete sentence, describe what you see
occurring in the above illustration.
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Pressure Gradient Force directed from high to
low pressure

• The pressure gradient results in a force that is
  directed from high to low pressure and this force
  is called the "pressure gradient force".

• This pressure gradient force is responsible for
  triggering the initial movement of air.

Sketch the above illustration into your notebook.
Label it Pressure Gradient Force.
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Pressure Gradient Force directed from high to
low pressure
Bonus Identify the mistake made by the creator
of these graphics.
1. Study these two illustrations. 2. Describe
what you see occurring by comparing the
pictures. 3. Write a description of your
comparison in two or three sentences.
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• Pressure Gradients cause wind
• Wind begins with differences in air pressure,
  giving air a push.
• Wind Speed
• The greater the pressures difference, the
  stronger the wind.
• The smaller the distance between the HIGH and
  LOW pressure, the greater the wind.

Copy the above notes into your notebook. Complete
the following sentence Winds begin as a result
of _________________ and two things that will
make wind travel faster are _____________________
and _____________________.
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Coriolis Force

• Once air has been set in motion by the pressure
  gradient force, it undergoes a change from its
  original path. This change is called the
  "Coriolis effect" and it is a result of the
  earth's rotation.

What will happen to this ball as it moves toward
the edge? Click the picture to find out.
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Coriolis Force
If Earth did not rotate, wind and water would
move directly north and south between the Equator
and the poles. But Earth does rotate. Since the
Equator is moving more quickly to the east than
are the poles, winds and water traveling away
from the Equator are deflected to the east, to
the right in the Northern Hemisphere.
Conversely, since the poles move more slowly to
the east, winds and water traveling toward the
Equator will be deflected to the west, to the
right in the Northern Hemisphere.
? This is an important illustration.
Summarize these notes in your notebook, and draw
the illustration.
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Read only
Coriolis Force
Pressure differences tend to push winds in
straight paths. Yet winds follow curved paths
across the Earth. In simple terms, as air begins
flowing from high to low pressure, the Earth
rotates under it, making the wind follow a curved
path. In the Northern Hemisphere, the wind turns
to the right of its direction of motion. In the
Southern Hemisphere, it turns to the left. The
Coriolis effect is zero at the equator. The
Coriolis effect acts on air to cause winds. In
simple terms, in the Northern Hemisphere, while
the Coriolis effect is pushing the wind toward
the right, the pressure-gradient force, caused by
air pressure differences, is pushing the air
toward the center of the area of low pressure,
and for various reasons is stronger then the
Coriolis effect. The pressure gradient force and
the coriolis effect work together to create winds.
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Coriolis Force
Pressure Gradient Force directed from high to
low pressure
The pressure gradient force and the Coriolis
effect work together to create winds.
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Copy and label this illustration. Write a two
sentence description of this illustration.
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Copy and label this illustration. Write a two
sentence description of this illustration.
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Read only
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Copy and label this illustration. Write a four
sentence description of this illustration.
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• CLICK to View Animations
• CE affects plane travel
• 2. Observe how wind flow is affected by PGF and
  CE

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