Section 1 3 Global Convection and Wind Belts

Section 1 -3 Global Convection and Wind Belts

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

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) http: //www. boqueteweather. com/climate_article. htm

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

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

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

Convection Cells and Jet Streams Go Together

Jet Streams Meander

1 -3 Notes Quiz: Global Pressure and Wind Belts Name: _________ 1. List the latitudes with Global Low Pressure Belts with consistently large amounts of precipitation. (HINT: look at latitudes North and South - there are three) 2. List the latitudes with Global High Pressure Belts with consistently very little precipitation. (HINT: there are four) 3. Where and why do jet streams occur? 4. What is the name (and source) for winds moving toward the equator? 5. 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

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

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