Earth #4: Hadley Circulation, Coriolis Effect, Rain Shadow Effect

Question 1

Latitudinal Temperature Gradient

Answer 1

Toward Poles: Sun’s rays spread over larger area; take longer path through atmosphere

Near Equator: Sun’s rays strike Earth perpendicularly; more energy per square meter (heats Earth’s surface most intensely)

Note: If earth flat, no latitudinal temperature gradient b/c sun would hit all surfaces equally

Question 2

Hadley Circulation

Answer 2

Hadley Circulation: Pattern of warm air rising in tropics (equator) and descending as dry air near 30 N and S latitude

1. Sun’s heating causes uplift of hot, expanded air
2. This creates large band of low atmospheric pressure
3. Hot air cools as lifting and holds less moisture
4. Cool air condenses into cloud
5. Cloud rains at equator (tropical rain forest)
6. Subsidence of air (sinking/downward movement of air over wide area within high pressure area) creates large band of high atmospheric pressure
7. Clouds start moving outwards
8. Clouds lose moisture while raining
9. Clouds fall as cool, dry air

Thus, precipitation high at equator and low at 30 N and 30 S

Question 3

Coriolis Effect

Answer 3

Coriolis Effect:
Northern Hemisphere: Wind bends clockwise right

Southern Hemisphere: Wind bends counter clockwise left

Question 4

Rain Shadow Effect

Answer 4

Rain Shadow Effect: Area downwind of mountain/mountain range where little/no rain falls (rain travels w/ wind direction)

Tropical Zones (closer to equator): West of mountains

Temperate Zones (farther from equator): East of mountains