Winds and the Coriolis Effect
Wind
• What is wind?
• Wind is moving air. It moves from areas of
high pressure to areas of low pressure.
COLD AIR
HOT AIR
• 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.
• This motion of hot air rising and cold air
sinking causes WINDS to form and transfers
heat from the equator to the poles.
COLD
HOT
What in the world is the 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.
• 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.
• The Coriolis Effect
• 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
60o – Poles
• In the far north and south poles
• Cold, dense air sinks and moves away from
the poles.
Westerlies
30o - 60o
• 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
30o - Equator
• 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
GLOBAL WIND PATTERNS
GLOBAL WIND PATTERNS
DOLDRUMS
DRAW in
Journal!!
0o
STOP!!!
HEAT RISES!!!!!!!!!
Land Breeze and Sea Breeze…
LOCAL WINDS!!!
Land Breeze
 HAPPEN AT NIGHT!!!!
 As the LAND COOLS more rapidly than the
water, cool air moves toward the water.
Sea Breeze
 HAPPENS DURING THE DAY!!
 Air over the sea is cooler and this cool
air moves towards the warm land .