1.1 - Atmospheric Circulation Flashcards
What conditions are always associated with Low Pressure?
Rising air, clouds, and precipitation (producing vegetation)
What conditions are always associated with High Pressure?
Sinking air and clear skies (producing arid/desert like conditions)
What are the ‘surface’ trade winds?
Air that moves from high pressure to low pressure (at the surface)
What is the role of ocean currents?
Distribute heat from regions of surplus (equatorial) to regions of deficit (polar)?
Explain how atmospheric circulation determines the location of high rainfall areas?
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.
Explain how atmospheric circulation determines the location of arid (high pressure) areas?
High pressure air masses (at 30oN/S or polar regions) sink, leading to clear skies, no clouds, lack of rainfall to create dry conditions
Why is there an uneven pattern of global temperatures?
Solar insolation is concentrated at the equator (smaller surface area) and less concentrated at the poles (larger surface area).
What atmospheric conditions characterise the Hadley cell?
Low pressure, high rainfall at the equator and high pressure, clear skies at the tropics (30oN/S)
How many atmospheric cells are there in each hemisphere?
3 atmospheric cells:
- Hadley cell (O to 30o)
- Ferrell cell (30 to 60o)
- Polar cell (60 to 90o)
What is the role of atmospheric circulation?
Same as ocean currents - Distribute heat from regions of surplus (equatorial) to regions of deficit (polar)?