Download Wind

Where does our wind come from?
Vocab
Wind- the horizontal movement of air from an
area of high pressure to an area of low
pressure.
 Anemometer- has three to four cups
mounted on spokes that spin, measures
wind speed.
 Wind-chill factor- increased cooling caused
by wind.
 Local Winds- winds that blow over short
distances

Sea breeze- a breeze that blows in from an
ocean or lake
 Land Breeze- flows from land out to sea
 Global Winds- blow in a specific direction
over a long distance.
 Coriolis Effect- the curving of wind by the
earths rotation.
 Latitude- the distance from the equator.,
measured in degrees
 Jet Streams- about 10km above earth. Blow
west to east about 200km to 400km.

What is Wind

Winds are caused by differences in air
pressure
 It occurs when warm air rises and cold air
moves under it.
Local Winds

Caused by the uneven heating and
cooling of the earth’s surface within a
small area.
Global Winds
Occur in the same way local winds do
however they are over a larger area.
Coriolis Effect
The Earth moves from West to East very
quickly
 This movement causes the convection
currents to move to the west

Global Convection Currents
Warm air rises at the equator and sinks
at the poles
 This causes a giant convection current,
and happens in 3 zones

 The Hadley Cell which is near the tropics
 The Ferrell Cell which is near the temperate
area
 The Polar cell near the poles
Wind Belts

Doldrums

 Little or no wind near
equator due to air
heating quickly

 Steady wind between
Equator and 30 degrees

Horse Latitudes
Prevailing westerlies
 Moves from west to
 30 degrees North or
South, of calm wind.
Due to sailors threw
horses overboard due to
lack of food
Trade Winds
east. Between 30 and
60 degrees

Polar easterlies- move
from the east above
60 degrees. Meets the
Prevailing Westerlies
Jet Streams
Jet Streams. Constant fast moving air
about 10 km above the earth
 Moves above the wind cells
 2 jet streams

 The polar stream- in between Ferrell and
Polar cells
 The subtropical stream –
in between the Ferrell and
Hadley Cells