Winds (7.6)Winds (7.6)
Wind Notes Chapter 7.6Wind Notes Chapter 7.6
Winds are caused by differences in airpressure. They move from highpressure areas to low pressureareas.
The sun causes different air pressuretherefore the ultimate source ofenergy that powers the wind.
Whatcreateswind?
Cold Air Warm Air Cold Air Warm Air
High Pressure Low Pressure High Pressure Low Pressure
More Dense Less Dense More Dense Less Dense
The molecules like to move to aless crowded area. Their movementcauses wind.The molecules like to move to aless crowded area. Their movementcauses wind.
What createsWind?
H
L
Wind speed is measured usingan anemometer.Wind speed is measured usingan anemometer.
Is measured using a wind vaneor wind sock.Is measured using a wind vaneor wind sock.
MeasuringWind
Wind Speed
Wind Direction
L
The name of the wind tellsyou where the wind iscoming from. North windcomes from the North.The name of the wind tellsyou where the wind iscoming from. North windcomes from the North.
MeasuringWind
Location A
Location B
H
L
N
E
W
S
West wind blows from the west to the east.
Name: West wind Wind direction: East
Location A
Location B
H
L
Location A
Location B
H
L
North Wind
Blows South
East Wind
Blows West
N
E
W
S
A.What is the name of Each wind
B.What Direction is the wind blowing?
A.
B.
A.
B.
A.
B.
A.
B.
N
E
W
S
Northwest Wind
Southeast
West Wind
East
Northeast Wind
Southwest
South Wind
North
What type of airpressure creates rain?What type of airpressure creates rain?
Low air pressurecreates rain because allthe water in the airrises and then coolscreating rain clouds.Low air pressurecreates rain because allthe water in the airrises and then coolscreating rain clouds.
Local winds are winds thatblow over short distances andare caused by unequal heatingof Earth’s surface within a smallarea.Local winds are winds thatblow over short distances andare caused by unequal heatingof Earth’s surface within a smallarea.
Ex: Sea breeze, land breeze,Ex: Sea breeze, land breeze,
Local Winds
Sea BreezeSea Breeze
Land BreezeLand Breeze
Mountain-ValleyBreezes
Compressional Heating Winds (Santa Ana Winds, Chinooks, Foehn Winds)Compressional Heating Winds (Santa Ana Winds, Chinooks, Foehn Winds)
Santa AnaWindsSan Diego, October 2003Santa AnaWindsSan Diego, October 2003
Global WindsGlobal Winds
Winds that blowsteadily from specificdirections over longdistances.Winds that blowsteadily from specificdirections over longdistances.
caused by unequalheating of Earth’ssurface.caused by unequalheating of Earth’ssurface.
Coriolis Effect
The effect of Earth’srotation on thedirection of windsand currents.
Due to the spinningof the earth windblows to the east andwest instead ofNorth and South.
Polar EasterliesPolar Easterlies
Wind belts that extendfrom the poles to 60°latitudeWind belts that extendfrom the poles to 60°latitude
Formed from cold sinkingair moving from the polescreating coldtemperaturesFormed from cold sinkingair moving from the polescreating coldtemperatures
Strong polar winds due to lowfriction
WesterliesWesterlies
Wind belts foundbetween 30° and 60°latitudeWind belts foundbetween 30° and 60°latitude
Flow towards the polesfrom west to eastcarrying moist air overthe Unites StatesFlow towards the polesfrom west to eastcarrying moist air overthe Unites States
Trade WindsTrade Winds
Winds that blow from30° almost to theequatorWinds that blow from30° almost to theequator
Called the trade windsbecause of their use byearly sailorsCalled the trade windsbecause of their use byearly sailors
Some of the air moves back towardsthe equator as it sinks...
Tradewinds:
Where do you think theygot their name?
Who were these windsimportant to?
DoldrumsDoldrums
Located along theequator where no windsblow because the warmrising air creates and areaof low pressureLocated along theequator where no windsblow because the warmrising air creates and areaof low pressure
There was an area that sailors avoided withtheir lives...There was an area that sailors avoided withtheir lives...
THE DOLDRUMS...is the area around theequator where the windcompletely dies out...which meant death assoon as the fresh waterran out.
Horse LatitudesHorse Latitudes
Occur at about 30° north andsouth of the equator where thewinds are very weakOccur at about 30° north andsouth of the equator where thewinds are very weak
Most deserts on the Earth arelocated here because of thedry airMost deserts on the Earth arelocated here because of thedry air
Jet StreamJet Stream
The jet streams arenarrow belts ofhigh speed windsthat blow in theupper troposphereand lowerstratosphereThe jet streams arenarrow belts ofhigh speed windsthat blow in theupper troposphereand lowerstratosphere
Separates warm airfrom cold airSeparates warm airfrom cold air
West to eastWest to east
Isobaric Chart Showing the difference in airpressure for the United States.
High Pressure, Low Pressure combined with Local and Globalwinds is what creates weather.
Question 1Question 1
What causes winds?What causes winds?
AnswerAnswer
Winds are caused by theuneven heating of Earth’ssurface, which causespressure differencesWinds are caused by theuneven heating of Earth’ssurface, which causespressure differences
Question 2Question 2
What are the three types ofglobal winds?What are the three types ofglobal winds?
AnswerAnswer
Polar EasterliesPolar Easterlies
WesterliesWesterlies
Trade WindsTrade Winds
Question 3Question 3
What is the differencebetween a land breeze and asea breeze?What is the differencebetween a land breeze and asea breeze?
AnswerAnswer
Sea breezes occur during the day whenthe land is warmer than water and aland breeze occurs at night when thewater is warmer than landSea breezes occur during the day whenthe land is warmer than water and aland breeze occurs at night when thewater is warmer than land
High Pressure, Low Pressure combined withLocal and Global winds is what creates weather.