Coriolis Effect and Wind Patterns
3rd factor that affects weather
(Wind Speed and Direction)
Wind
• What is wind?
• Wind is moving air. It moves from areas of
high pressure to areas of low pressure.
• What is the main source that drives the
winds?
• The SUN!!!
What causes wind?
• Winds are caused by the uneven heating and
cooling of the earth. When warm air rises,
cooler air flows underneath creating a
convection current, thus causing wind!
Coriolis Effect
• The results from the earth’s rotation causing freely
moving objects (such as airplanes) to veer toward
the right in the Northern Hemisphere and to the left
in the Southern Hemisphere.
• Affects things like wind, ocean currents, airplanes,
and missiles.
http://www.classzone.com/books/earth_scien
ce/terc/content/visualizations/es1904/es1904
page01.cfm
• Another example of the Coriolis Effect is a merrygo-round.
• If you tried to pass a ball across to someone on
the other side, the ball would be deflected instead
of moving in a straight line.
• http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/
fw/gifs/coriolis.mov
• Without the Coriolis Effect, wind and weather
patterns would be more stabilized because they
would move in a straight line instead of
“deflecting” to the right or left. This means there
would be fewer changes in the atmosphere
(weather patterns)—this would be boring!
Global Winds
• Wind patterns on Earth.
• Helped early sailors navigate the oceans
• 4 Types of Global Winds:
1.
2.
3.
4.
Polar Easterlies
Westerlies
Trade Winds
Doldrums
Polar Easterlies
• In the far north and south poles
• Cold, dense air sinks and moves away from
the poles.
Westerlies
• Above the subtropical highs in the Northern
Hemisphere and below the subtropical highs
in the Southern Hemisphere, winds blow from
the West towards the East.
Trade Winds
• Air movements toward the equator.
• Warm, steady breezes that blow almost continuously.
• The Coriolis Effect makes the trade winds appear to
be curving to the west, whether they are traveling to
the equator from the south or north.
Doldrums
• Area of calm weather near the equator
• Converging trade winds produce general upward winds as
they are heated, so there are no steady surface winds.
• Cloudy, rainy weather develops most afternoons (tropical
rainforests)
GGlobal Winds