4.5 - Global Wind Patterns

Question 1

Air Properties

Answer 1

1. Warm air rises
2. Warm air holds more moisture than cold air
3. rising air expands and cools
4. cool air can’t hold as much H2O vapor so it condenses - and turns to rain
5. After cooling and expanding, air sinks

Question 2

Explain the air cycle at the Hadley Cell

Answer 2

1. At the equator, more direct sunlight is on the earth
2. The air is warm, and warm air rises, expands, and cools
   - when the air expands and cools, the H2O vapor condenses into rain
3. The air continues to rise, cool, and expand
4. The cooling, expanding air spreads out as it moves down
5. Cool, dry air sinks back down to earth at the 30°N&S
   - Deserts form here because of the lack of moisture in the air

Question 3

What way does air travel?

Answer 3

From high to low pressure

Question 4

Explain the Coriolis Effect

Answer 4

• the deflection of objects traveling through the atmosphere due to the spin of the earth
• Air at 30° moves back to low pressure at the equator
• the earth is spinning from West to east from 0-30°
  - The wind blows from East to West
• The earth spins faster at 30° than 60°
  - from 30° to 60° the wind blows from West to East

Question 5

Describe global wind patterns

Answer 5

1. Air moves out from 30° to 0° and 60° due to the high pressure at 30° and low pressure at 0&60°
   - Air rising at equator = low pressure
   - Air sinking down at 30° = high pressure
   - The combination of the two creates the Hadley cell
2. Eastern trade winds: 0-30°
   - Blow from east to west
   - drives ocean current clockwise in the northern hemisphere and counterclockwise in the southern
   hemisphere
3. Westerlies: 30-60°
   - Blows from west to east
   - Drives the weather patterns of North America (from west coast to east coast)