Winds

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Winds Weather

• Weather Dynamics
• Science 20S

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Some Information

• At the earths surface, air warms, becomes less
  dense and rises.
• Cooler and denser air sinks
• The difference in air temperature and density
  initiates worldwide movements of air, and global
  wind patterns begin

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Heat Transfer

• The movement of heat from a warmer object to a
  cooler one
• There are three methods Convection, conduction
  radiation

Atmospheric convection currents are responsible
for ocean currents global wind patterns.
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Convection

•  Heat travels through air. 
• Cold air is heavier than warm air. 
• Cold and warm air meet, the cold air sinks below
  the warm air and forces the warm air to move
  upward. 

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Prevailing Winds

• the wind that blows most frequently across a
  particularly region
• direction of wind is measured from where the air
  is coming from.

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Information on Prevailing Winds
Interactive wind patterns
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Polar Easterlies Polar Cell (N S Hemispheres)
Polar Cells
Polar Easterlies
Polar Easterlies
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Westerlies Ferrel Cell
Ferrel Cell
Ferrel Cell
Westerlies
Westerlies
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N. E. Trade Winds Hadley Cells
Hadley Cell
Hadley Cell
N. E. Tradewinds
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S. E. Trade Winds Jet Streams
Polar Jet Stream
Subtropical Jet Stream
Polar Easterlies
Westerlies
N. E. Trade Winds
S. E. Trade Winds
Westerlies
Polar Easterlies
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The Jet Stream
Picture taken from the Space Shuttle

• Currents of fast moving air in the upper levels
  of the troposphere
• winds blow from west to east in jet streams (due
  to the earths rotation) (can become N to S)
• Wind speed varies from 50 km/h to 300 km/h
• Position of the jet stream denotes the location
  of strongest temperature contrast between
  different latitudes
• jet streams are the strongest for both the
  northern and southern hemisphere winters.

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Prevailing Winds The Jet Stream
Note the Jet Stream appears between the
different cells of prevailing winds
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The Coriolis Effect

• the apparent change in direction of a moving
  object in a rotating system
• Earth rotates eastward, an object travelling from
  north to south will appear to move to the right
• more predominant closer to the poles

Check out the animation of a plane flying from
one place to the other
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More on Coriolis
Click here for more animations of Coriolis Force