Wind Notes:

Remember … Air has mass and takes up space. Air pressure – the mass of the air being pulled down on an area of the earth’s surface. It pushes in all directions - it does not crush objects

Factors that affect Air Pressure: Temperature The amount of air above it How fast it is moving

Wind: Horizontal movement of air (fluid) from an area of high pressure to low pressure Low Pressure High Pressure

example A to B movement= NO ENERGY (wind) B to A movement= ENERGY (fan) B

1) The greater the pressure difference, (temp difference) Wind facts: 1) The greater the pressure difference, (temp difference) The greater the WIND! 2) Described by original direction and speed ex: Northeastern wind at 50mph

Measurement of Wind: Wind vane- measures wind direction 2) Anemometer: measures wind speed 3) Wind-chill factor: increased cooling caused by the wind * cool breeze blowing by skin removes heat

2)Planetary (or Global) Winds Two Types: Local Winds 2)Planetary (or Global) Winds

Local Wind: effect small areas (beach, lake) 1) SEA BREEZE P P land water Blue = Cool Red = Warm

Air above land heats faster SEA BREEZE * Land heats faster than the water Air above land heats faster Warm air rises creating LOWER pressure over land High Pressure over water COOL air moves TOWARD LAND= CLOCKWISE

2).Land Breeze P P land water

Land cools faster than water Pattern of circulation is reversed LAND BREEZE Land cools faster than water Pattern of circulation is reversed Air moves toward water COUNTERCLOCKWISE

Coriolis Force/Effect: Due to Earth’s rotation, Winds in Northern Hemisphere curve to the RIGHT = CLOCKWISE Winds in Southern Hemisphere curve to The LEFT= COUNTERCLOCKWISE NH equator SH

PLANETARY/GLOBAL WINDS *Caused by: Uneven heating of Earth’s surface *Warm air rises at the equator and *Cold air sinks at the poles

Major Wind Systems 1) Trade Winds:- steady winds blowing to the southwest. Ships used them (“traders”) to travel with goods. 2) Prevailing Westerlies:-blow from southwest to northeast. Moves WEATHER across the United States and Canada

3) Polar Easterlies:- due to the Coriolis effect, winds at North pole rotate clockwise. Winds at the South pole rotate counterclockwise 4) Jet Stream:- fast moving streams of air higher than other wind systems. Narrow and Strong Pilots use them

5) Doldrums:- windless zone at the equator. (remember CONVECTION) 6) Horse Latitudes:- windless zone at 30 North and 30 south latitudes (Tropic of Cancer/Tropic of Capricorn)

Diagram of winds