Global Winds
Global Winds and Local Winds
What causes wind?
1. Wind is caused by the movement of air which
is caused by differences in air pressure.
Differences in air pressure are caused by the
uneven heating and cooling of the Earth.
2. Warm air is less dense and creates an area
of low pressure
3. Cold air is more dense and creates an area of
high pressure.
GLOBAL WINDS
Questions
What winds would Columbus have used
to travel from Spain to the Caribbean?
Which winds would he have needed to
return to Europe?
Would winds have favored European
explorers seeking to travel east around
the tip of Africa?
Trade winds
Prevailing Westerlies
No
POLAR EASTERLIES
GLOBAL WIND
1. Extend from the North and South Poles
poles to 60 degrees latitude.
2. Polar easterlies carry cold arctic air
WESTERLIES- GLOBAL WIND
1. These wind belts lie
between 30 and 60
degrees latitude.
2. Westerlies flow
toward the poles
from west to east.
3. Affects the weather
in the United States.
TRADE WINDS
1. Winds that blow from 30
degrees latitude almost to
the equator, 0 degrees
latitude.
2. Winds are named for the fact
that these winds moved
sailors across the Atlantic
Ocean from Europe to the
Americas.
3. Northeast Trade Winds blow
from 30* North toward the
equator, 0*
4. Southeast Trade Winds blow
from 30* South toward the
equator, 0*
DOLDRUMS- GLOBAL WIND
The trade winds
meet at an area
called the doldrums.
1. This area is located
around the equator,
0 degrees latitude.
2. This is an area of
low pressure where
there is very little
wind.
HORSE LATITUDES-GLOBAL WIND
1. Located at 30 degrees
north and 30 degrees
south latitude.
2. An area of little wind.
Name given by sailors
who got stuck here
because of lack of wind,
travel time was slow.
Horses were thrown
overboard to save water
for sailors.
THE CORIOLIS EFFECT
1. The curving of winds due to the Earth’s
rotation is called the Coriolis Effect.
2. Because of the Coriolis Effect winds
curve to the east and west.
Winds traveling north curve to the right,
or east.
Winds traveling south curve to the left
or west
THE JET STREAM
1. The jet streams are narrow
belts of high-speed winds
that blow in the upper
troposphere and lower
stratosphere.
2. Unlike global winds, jet
streams do not follow
regular paths.
3. Knowing the path of the jet
stream can help airplane
pilots travel faster as they
ride the jet stream.
4. Meteorologists can track a
storm if they know the
location of the jet stream.
Local Winds
1. Move short distances and blow from any direction.
Geographic features, a shoreline or a mountain can
produce temperature differences.
2. Sea breeze
3. Land breeze
www.classzone.com/books/earth_science/terc/conten
t/visualizations/es1903/es1903page01.cfm?chapter_n
o=19
3. Mountain Breeze
4. Valley Breeze
SEA BREEZE- LOCAL WIND
During the day air over ocean is cooler
and forms high pressure.
Warm air over land, low pressure.
Cool air moves inland and overtakes
area of warm air.
Cool air has higher pressure than warm
air.
1. Wind moves from sea toward land.
LAND BREEZE- LOCAL WIND
At night air over ocean is warmer, warm
air rises and creates low pressure.
Air over land is cooler and creates high
pressure.
Cool air moves toward ocean causing a
land breeze.
1. Wind moves from land toward sea.
Sea Breeze and Land Breeze
Animation
http://www.classzone.com/books/earth
_scienc/terc/content/visualizations/es19
03/es1903page01.cfm?chapter_no=19l
ocal breeze
MOUNTAIN BREEZE
LOCAL WIND
At night mountains cool
faster than valley.
Cool air moves
downward and creates
a mountain breeze.
1. Mountain breeze moves
down.
2. Cold air sinks.
3. Cold air / High pressure
VALLEY BREEZE
LOCAL WIND
Sun warms the valley
and the air above it.
Warm air rises and
moves up mountain
causing a valley breeze.
1. Valley breeze moves
up.
2. Warm air rises.
3. Warm air /low pressure
High Pressure and Low Pressure
1. Low Pressure / Warm
Air
2. Cloudy weather occurs
with low pressure.
3. High Pressure / Cold Air
4. Clear weather occurs
with high pressure
Quiz
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Which type of breeze occurs when cool air moves from water toward land?
Which type of breeze occurs when cool air moves from land toward water?
What is the area of low pressure around the equator called? There is low
pressure and little wind here.
High speed winds that occur in the upper troposphere and lower
stratosphere?
Winds in the North curve to the right, or east, and winds in the south curve
to the left, or west. This is known as….
Which wind belt affects most of the United States? They blow from 30* to
60* north and south.
Cloudy weather occurs with……………pressure.
Clear weather occurs with………………pressure.
These winds blow from any direction and move short distances.
Cold winds that blow from the poles to 60* latitude are called…..
These winds are located at 30* N and 30* south latitude.
These winds blow from 30* North and 30* South toward the equator.
This local wind is caused by cool air moving down the side of a mountain
This local wind is caused by warm air moving up from a valley.
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Sea breeze
Land breeze
Doldrums
Jet stream
Coriolis effect
Westerlies
Low pressure
High pressure
Local winds
Polar easterlies
Horse latitudes
Trade winds
Mountain breeze
Valley breeze
Answers