1) Hazardous Earth Flashcards
What are winds?
Movements of air on a large scale
What causes winds?
Differences in air pressure
What causes differences in air pressure?
Different temperatures causing movement
How does air pressure affect winds?
WInds mmove from high pressure areas to lower pressure areas
What are the 3 atmospheric circulation cells called?
Hadley
Ferrel
Polar
What does cool sinking air form?
High pressure belts of wind
What does warm rising air form?
Low pressure belts on wind
How many global atmospheric circulation cells do the North and Suth poles have each?
3
What are westerlies?
Surface winds that blow from 30 degrees to the poles
What direction do westerlies blow in the southern hemisphere?
North-west to south-east
What direction do westerlies blow in the northern hemisphere?
South-west to north-west
What are trade winds?
Surface winds that blow from 30 degrees to the equator
What direction do trade winds blow in the southern hemisphere?
South-east to north-west
What direction do trade winds blow in the northern hemisphere?
North-east to south-west
What does the global atmospheric circulation model describe?
How air circulates between low and high pressure belts
What happens to air at 30 degrees?
Cool air falls
High-pressur ebelt with minimal rainfall and no clouds
What happens to air at 60 degrees?
Cold air blown from poles meets warm surface winds
RIses and forms a low pressure belt
Air splits, some to equator and some to poles
What happens to air at the poles?
Cool air sinks
High pressure belt
Moves back towards equator as surface winds
What do ocean currents transfer?
Heat from warmer to cooler areas
What do surface currents do?
Transfer heat from the equator to cooler regions
What are deep ocean currents caused by?
Differences in water density
What is thermohaline circulation?
1) Water freezing at the poles causes the surrounding water to become saltier and denser
2) Sinking of dense water lets warm water flow near the surface which cools and sinks creating a cycle
What are surface currents caused by?
Winds
What determines arid and dry regions?
Pressure belts