Transcript Global Winds

Quickwrite: Complete 1-4
1. Describe how wind is created.
2. What is the relationship between
density/temperature and pressure?
3. What happens to air pressure as I hike up
a mountain?
4. What instrument measures air pressure?
Definition: winds that blow from different
directions over long distances on earth
F.Q: Which way does earth rotate?
F.Q: What controls the global
atmospheric circulation?
F.Q: What are the major global wind
belts?
Which way does Earth rotate?
https://www.youtube.com/watch?v=6SLW_b3luO4
2. Make your globe spin in the direction the earth spins.
1.
What controls the global
atmospheric circulation?
A: Uneven heating of earth by sun and Coriolis
Effect
Equator-sun strikes
Earth almost directly so
it’s hot at the equator
Poles-sun’s energy heats
up a larger area so
Poles are not as hot as
Equator.
Global Convection Currents in
Non-rotating Earth
Uneven heating of earth’s surface by sun creates giant
convection current in the atmosphere.
1.Air at equator gets heated
up, expands and rises.
2. Air at equator is low
pressure.
3. Air at the poles is cool.
It condenses and sinks.
4. The air at the poles is high pressure.
5. Air always moves from high to low pressure.
In a non-rotating earth:
 Air from the poles sink and travels towards the equator
(high pressure to low pressure). Once the air at the
equator is heated, it rises and expands back towards
the poles.
 If earth did not rotate,
we would only see 1
convection current in
each hemisphere.
Coriolis Effect
 BUT Because the Earth rotates and because of the
Coriolis Effect, the earth has many global
atmospheric convection currents.
 The Coriolis Effect is the movement of particles (such as
air) to the right in the Northern Hemisphere
 https://www.youtube.com/watch?v=mcPs_OdQOYU
 (video of Coriolis Effect)
 How about the South?
 They move to the left
(Coriolis Effect Activity Using Write-On Globes)
Coriolis Effect
Northern hemisphere-air deflected to right
Southern hemisphere-air deflected to left
Global Winds
 Global wind patterns are caused by:
 Unequal heating of
earth’s surface
(poles vs. equator)
 Coriolis Effect
Warm Moist Air Rises
Cool Dry Air Sinks
Warm Moist Air Rises
Cool Dry Air Sinks
Cold Moist Air Rises
Cool Dry Air Sinks
Warm Moist Air Rises
Cool Dry Air Sinks
Cold Moist Air Rises
Very Cold Air Sinks
Cold Moist Air Rises
Cool Dry Air Sinks
Warm Moist Air Rises
Cool Dry Air Sinks
Cold Moist Air Rises
Very Cold Air Sinks
Very Cold Air Sinks
H
Cold Moist Air Rises
L
H
Cool Dry Air Sinks
L
Warm Moist Air Rises
Cool Dry Air Sinks
Cold Moist Air Rises
Very Cold Air Sinks
H
H
L
H
L
H
L
H
L
H
Wind Moves
from HIGH
to LOW
Objects are
deflected to
the
RIGHT in the
Northern
Hemisphere
Remember!
Wind gets its name
from the
direction it is blowing
FROM!
Northern Wind Patterns
 Polar Easterlies
 90 – 60 latitude from the east
 Prevailing Westerlies
 60 – 30 latitude from the west
 Trade winds
 30 – 0 latitude from the East
Latitude Nicknames
 Horse Latitudes
 30 latitude
 Named because the boats stalled and the horses had to
go!
 Doldrums / Intertropical Convergence Zone (ITCZ)
 Equator
 Trade winds converge from north and south
 Named because boats also got stranded here
Jet Streams
 Jet Streams form at
latitudes where wind
systems come together
 High speed westerly
winds form high above
the surface