Transcript Winds 15.3

Warm Up
Convection, conduction or radiation?
1.
2.
3.
Your tongue gets burned from drinking a
cup of really hot chocolate.
Your basement is cooler than your attic in
the summer.
You get a sunburn on your face while at
the pool in the summer.
Winds
What causes winds?
 A wind
is the movement of air caused by
differences in air pressure.
High Pressure
Low Pressure
Low Pressure
WIND
WIND
Earth’s Surface
Global Winds
 Winds
that blow steadily from specific
directions are global winds.
 Warm air rises at the equator and falls at
the poles.
 The movement of air between the equator
and the poles produces global winds.
 The way that Earth’s rotation makes winds
curve is called the coriolis effect.
Global Wind Belts
1.
2.
3.
4.
5.
Polar Easterlies
Westerlies
Trade Winds
The Doldrums
The Horse Latitudes
Global Wind Belts
Horse Latitudes
Horse Latitudes
Jet Streams
 Belts
of high speed winds
 Hundreds of kilometers
wide, but only a few
kilometers deep.
 Blow from west to east at
speeds of 200-400 km/hr.
 Help airplanes save fuel
and time when traveling
east.
Local Winds
 Local
winds are winds that blow over short
distances.
 They are caused by unequal heating of
Earth’s surface within a small area.
 Two types of local winds are sea breezes
and land breezes.
Sea Breeze (Morning)
Land heats up faster than water. Hot air over land
rises (Low Pressure), cool air over water falls
(High Pressure). Winds move from the water
(High Pressure) to the land (Low Pressure).
Land Breeze (Evening)
Land cools off faster than water. Cool air over land
falls (High Pressure), warm air over water rises
(Low Pressure). Winds move from the land (Low
Pressure) to the water (High Pressure).
Valley Breeze
 Day
= sun warms air on mountain slopes.
Hot breeze blows from the valley up the
mountain as the hot air rises (low
pressure)
Hot air rises from the
valley creating a valley
breeze
Mountain Breeze
 Night
= air on mountain cools and sinks
(high pressure) creating a cool breeze
from the mountain down into the valley.
Cool air falls from the
mountain top creating
a mountain breeze