Winds WS - BrettLaGrange

Date
Name
Class
Winds
Guide for
Reading
I Whatcauses
winds?
o Whatarelocal
windsandglobal
winds?
I Wherearethe
majorglobalwind
beltslocated?
50. I
A wind is the horizontal movement of air from an areaof high presA
r.rr. to an area of lower pressure.All winds are causedby differences in air pressure. Most differencesin air pressure are causedby
unequalheating of the atmosphere.Cool, denseair hashigher air pressure
so it flows underneathwarm) lessdenseair, forcing the warm air to rise.
Winds are describedby their direction and speed.Wind direction is
determinedwith a wind vane.The name of a wind is the direction the
wind is coming from. Wind speedis measuredwith an anemometen
Wind blowing over your skin removesbody heat. The increasedcooling that a wind can causeis called the wind-chill facton
Localwinds arewinds that blow over short distances.Localwinds are
caused by unequal heating of Earth's surface within a small area.
Local winds form only when no winds are blowing from farther away.
The sun heatsland faster than water, so during the day air over land
becomeswarmer than air over water.The cool air blows inland from the
water and movesunderneaththe warm air. The flow of air from an ocean
or lake to the land is called a seabreeze or a lake breeze.At night, land
cools more quickly than water, so air over land becomescooler than air
over water.The cool air blows toward the water from the land and moves
underneath the warm air. The flow of air from land to a body of water is
calleda land breeze.Seaand land breezesover a large region that change
direction with the seasonsare calledmonsoons.
Winds that blow steadilyfrom specificdirectionsoverlong distancesare
calledglobalwinds.Warm air risesat the equatorand cold air sinksat the
poles,causingwinds at Earths surfaceto blow from the poles toward the
equator. The movement of air between the equator and the poles producesglobalwinds. BecauseEarth is rotating, globalwinds do not follow
a straight path. The way Earth'srotation makeswinds curve is called the
Coriolis effect.In the Northern Hemisphere,global winds curve to the
right. In the SouthernHemisphere,global winds curve to the left.
The Coriolis effect and other factors produce a pattern of calm areas
and wind belts around Earth. The calm areasare calledthe doldrums and
horse latitudes. The major global wind belts are the trade winds, the
prevailingwesterlies, andthe polar easterlies.Latitude is a measureof
distancenorth and south of the equator.The trade winds blow between
the equator and 30o north and south latitude, the prevailing westerlies
between30oand 60onorth and south latitude, and the polar easterlies
between60onorth and south latitude and the poles.
About 10 kilometers above Earth'ssurfaceare bands of high-speed
winds calledjet streams. They blow from west to east.
Resources
Teaching
Weatherand Climate
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T'
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Name
Class
Date
Winds
I Understanding Main ldeas
Identify the global wind beltsin thefigure below.
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t Building Vocabulary
If the statementis true, write true. If it isfake, changethe underlinedword or words
to makethestatementtrue.
6. A wind is a horizontal movementof air from an areaof high pressure
to an areaof lower pressure.
7. Wind speedis measuredwith a wind vane.
8. The increasedcoolingthat a wind can causeis calledthe Coriolis effect.
9. Local winds arewinds that blow over short distances.
10. The flow of air from an oceanor lake to the land is called a land breeze.
I
o
11. The flow of air from land to a body of water is calleda seabreeze.
-F
o
(L
12. Seaand land breezesover a largeregion that changedirection with the
seasonsare calledglobalwinds.
I
13. Winds that blow steadilyfrom specificdirectionsover long distances
are calleddoldrums.
14. The way Earth's rotation makeswinds curve is called the prcyading
westerlies.
15. Bandsof high-speedwinds about 10 kilometersaboveEarth'ssurface
are calledpolar easterlies.
Weatherand Climate
TeachingResources I I 51