1. 14-4 Movement of Air
Wind – caused by the uneven heating of Earth’s atmosphere.
*heats unevenly due to its tilt and curved surface
*difference in pressure – warm air rises, cold air sinks
*AIR MOVES FROM HIGH PRESSURE TO LOW PRESSURE!
Where is the air on Earth heated the most? Least? Why?

2. The Coriolis Effect Caused by Earth’s rotation
Deflects all free moving objects to the right, north of the equator
To the left, south of the equator
Ex; air, water, rockets
Think of a merry-go-round and throwing a ball from it

3. Planetary Wind Systems
Doldrums – windless zone at the equator
Hot air rises straight up
No horizontal movement
Sailors got stuck here
Trade winds – between equator & 30 degrees N&S latitude
In n. hemisphere they blow sw
In s. hemisphere they blow nw
Horizontal winds, good sailing

4. Planetary Wind Systems Con’t.
Horse latitudes – approx. 30 degrees N& S of the equator
Air has cooled, stops moving towards the poles and sinks
No horizontal movement, windless zone
Sailors got stuck, threw horses off ships, some say they ate the horses

5. Wind Systems con’t Prevailing westerlies-
Between 30&60 degrees N&S latitude
Responsible for much of US & Canada’s weather
Blow from sw to ne in n. hemisphere
Polar easterlies -60 degrees N&S latitude to the poles
Blow from the ne to sw near the North Pole

6. Other Winds on Earth Jet stream – narrow belts of strong winds
Near the top of the troposphere
2 in each hemisphere, blow west to east
Latitude and altitude change
Jet streams affect our weather
Bring cold weather when they drop down in latitude

7. Other Winds Con’t. Sea breezes – wind blowing from sea to land
Happens during the day
Land warms faster than water, heating air over it by conduction
Warm air rises, allowing cool air from over the water to move in, thus creating the wind

8. Other winds Con’t
Land breezes – winds traveling from the land to the sea
At night, land cools faster than water
Warm air over the water rises
Cool air over the land moves out over the water
This creates a wind from the land to the sea