1.1 - Atmospheric Circulation

Question 1

What conditions are always associated with Low Pressure?

Answer 1

Rising air, clouds, and precipitation (producing vegetation)

Question 2

What conditions are always associated with High Pressure?

Answer 2

Sinking air and clear skies (producing arid/desert like conditions)

Question 3

What are the ‘surface’ trade winds?

Answer 3

Air that moves from high pressure to low pressure (at the surface)

Question 4

What is the role of ocean currents?

Answer 4

Distribute heat from regions of surplus (equatorial) to regions of deficit (polar)?

Question 5

Explain how atmospheric circulation determines the location of high rainfall areas?

Answer 5

Warm (less dense) air rises, then cools and condenses (at the equator)
OR… Warm (less dense) air meets cold (more dense) air at 60oN/S, and rises and cools to produce frontal rainfall.

Question 6

Explain how atmospheric circulation determines the location of arid (high pressure) areas?

Answer 6

High pressure air masses (at 30oN/S or polar regions) sink, leading to clear skies, no clouds, lack of rainfall to create dry conditions

Question 7

Why is there an uneven pattern of global temperatures?

Answer 7

Solar insolation is concentrated at the equator (smaller surface area) and less concentrated at the poles (larger surface area).

Question 8

What atmospheric conditions characterise the Hadley cell?

Answer 8

Low pressure, high rainfall at the equator and high pressure, clear skies at the tropics (30oN/S)

Question 9

How many atmospheric cells are there in each hemisphere?

Answer 9

3 atmospheric cells:

• Hadley cell (O to 30o)
• Ferrell cell (30 to 60o)
• Polar cell (60 to 90o)

Question 10

What is the role of atmospheric circulation?

Answer 10

Same as ocean currents - Distribute heat from regions of surplus (equatorial) to regions of deficit (polar)?