1. Global Convection and Wind Belts
Section 1-3
Global Convection and Wind Belts

2. What We’ll Discuss Today
Convection Cells and Pressure Belts
Coriolis Effect
Prevailing Winds

3. Convection Cells Where is the air…
humid and rising - low pressure ? (look for clouds)
dry and sinking - high pressure? (look for clear skies)
changing latitude as it flows along the surface?
Do You See the Convection Cells?
(follow the arrows)

4. “Turning of Air Masses because of the Spinning of the Earth”
The Coriolis Effect
“Turning of Air Masses because of the Spinning of the Earth”
Paper Plate Demonstration
The Effect on air masses which are changing latitude
Effect on air moving toward the equator
Turns left
Effect on air moving toward the poles
Turns Right
NOTE: Because of the Coriolis Effect, winds in large air masses associated with pressure systems rotate Clockwise in High Pressure Systems and Counterclockwise in Low Pressure Systems remember the clock is high and the counter is low

5. 3-D View of Global Convection
Rising Air: low pressure
rain band
Sinking Air: high pressure dry
Notice air changing latitudes at surface curves like on our plates

6. Convection Cells cause upper atmosphere “Jet Streams”
Jet Streams (GREEN AREAS)
form where convection cells meet in the upper atmosphere

7. Convection Cells and Jet Streams Go Together

8. Jet Streams Meander

9. 1-3 Notes Quiz: Global Pressure and Wind Belts Name: _________________
List the latitudes with Global Low Pressure Belts with consistently large amounts of precipitation. (HINT: look at latitudes North and South - there are three)
List the latitudes with Global High Pressure Belts with consistently very little precipitation. (HINT: there are four)
Where and why do jet streams occur?
What is the name (and source) for winds moving toward the equator?
What is the name (and source) for winds moving toward the poles?
Use the last slide of the presentation to help you complete the sketch on the back of this page

10. Spinning Earth (reality)
Stationary Earth
(imaginary)
Spinning Earth (reality)
What happens to a “Straight Line”
on a stationary plate
What happens to a “Straight Line”
on a stationary plate

11. Sketch and label the… Convection Cells (with arrow for direction), Pressure Belts (H and L), Prevailing Winds, and Jet Stream locations on this Model
Equator