Coriolis EffectGlobal Winds

Chapter 2.3Pages 57-60

Coriolis Effect• The effect of Earth’s rotation which makes

winds curve– Winds want to move in a straight line but the

earth rotates under them, making it seem as though the wind curved.

Coriolis Effect• In the Northern

hemisphere Earth rotates counter clock wise– All winds curve to

the right.

Coriolis Effect• In the Southern

hemisphere Earth rotates clock wise– All winds curve to

the left.

Global Winds• Winds that blow

steadily from specific directions over long distances.

• Caused by unequal heating of the surface.

Doldrums

Horse Latitudes

Horse LatitudesTrade Winds

Westerlies

Polar Easterlies

Trade Winds

WesterliesPolar

Easterlies

Global WindsH

L

HL

HLH

Global Winds

Doldrums

Horse Latitudes

Horse Latitudes

Trade Winds

Westerlies

Polar Easterlies

Trade Winds

Westerlies

Polar Easterlies

Exit PassWhat is the Coriolis Effect? (Why does it happen, and

what does it cause?)

Doldrums• Located: At the

equator

• Area of Low Pressure– Rising Air

• Definition: a state of inactivity or stagnation

• Winds: Calm

Doldrums

Horse Latitudes

Horse Latitudes

L

Horse Latitudes• Located: 30°N and

30°S• Area of high

pressure– Sinking air

• Winds: Calm– Sailors would get trapped

and run out of food and water, they threw their horses overboard.

Doldrums

Horse Latitudes

Horse Latitudes H

H

Trade Winds• Between the

– Equator and 30°N– Equator and 30°S

• Winds: Steady from the east– Sailors relied on

them to carry goods from Europe to West Indies and S. America.

Trade Winds

Westerlies

Polar Easterlies

Trade Winds

WesterliesPolar

Easterlies

Prevailing Westerlies• Location: Mid-

latitude winds – Between 30° & 60°N– Between 30° & 60°S

• Winds: From the west

• Cause our weather• Blow away from the

horse latitudes.

Trade Winds

Westerlies

Polar Easterlies

Trade Winds

WesterliesPolar

Easterlies

Polar Easterlies• Location: Between

– 60°N and 90°N– 60°S and 90°S

• Winds: FROM the east to west– Cold, low pressure

air from the poles sinks and flows away from the pole to the equator.

Trade Winds

Westerlies

Polar Easterlies

Trade Winds

WesterliesPolar

Easterlies

Jet Stream• 10km above the

Earth’s surface• Bands of high speed

winds– 200-400km/hr

• Blow from west to east

• Wanders north and south.

Exit PassDescribe two of the Global

Winds (Where is it located, H or L pressure, direction, etc.)