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!

• 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.

Coriolis Effect

http://www.classzone.com/books/earth_science/terc/content/visualizations/es1904/es1904page01.cfm

• Another example of the Coriolis Effect is a merry-go-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. Polar Easterlies2. Westerlies3. Trade Winds4. 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