GLOBAL WINDS 1

Objective for the day  By the end of the day…  SWBAT identify global winds, and describe how they are caused by global convection currents and the Coriolis Effect.  By the end of the day…  SWBAT identify global winds, and describe how they are caused by global convection currents and the Coriolis Effect. 2

Global winds  Local winds form only when no global winds are blowing.  Winds that blow steadily from specific directions over long distances are called global winds.  Local winds form only when no global winds are blowing.  Winds that blow steadily from specific directions over long distances are called global winds. 3

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5 Globe demonstration

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Global Convection Currents  Temperature differences between the equator and the poles produce giant convection currents in the atmosphere.  These convection currents are driving global winds.  Key Point #1: The movement of air between the equator and the poles by global convection currents produces global winds.  Temperature differences between the equator and the poles produce giant convection currents in the atmosphere.  These convection currents are driving global winds.  Key Point #1: The movement of air between the equator and the poles by global convection currents produces global winds. 8

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10 BUT, THIS DOES NOT EXPLAIN EVERYTHING ABOUT GLOBAL WINDS!

The Coriolis Effect  Global winds do not blow in a straight line from the poles toward the equator.  Why not?  The Earth is ROTATING.  Earth is rotating from west to east, making it seem as if the winds have curved.  Key Point #2: The way Earth’s rotation makes winds curve is called the Coriolis Effect.  Global winds do not blow in a straight line from the poles toward the equator.  Why not?  The Earth is ROTATING.  Earth is rotating from west to east, making it seem as if the winds have curved.  Key Point #2: The way Earth’s rotation makes winds curve is called the Coriolis Effect. 11

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Coriolis Effect Video 13

Coriolis Effect Rules  In the Northern Hemisphere, all global winds gradually turn toward the RIGHT.  In the Southern Hemisphere, all global winds gradually turn toward the LEFT.  In the Northern Hemisphere, all global winds gradually turn toward the RIGHT.  In the Southern Hemisphere, all global winds gradually turn toward the LEFT. 14 FROM THE PERSPECTIVE OF THE WIND MOVEMENT, NOT THE VIEWER OF THE GLOBE!

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Wind changes due to Coriolis Effect  Northern Hemisphere:  A North wind turns into a ___________________ wind.  A south wind turns into a ___________________ wind.  Southern Hemisphere:  A North wind turns into a ___________________ wind.  A South wind turns into a ___________________ wind. 16

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Exit Ticket 1) Air pressure is ___________ at the equator and ___________ at the poles. 2) What is causing global wind to be deflected from a straight path? 3) Draw how these winds would be deflected in the northern hemisphere. 21