Atmosphere Flashcards
What % of Insolation is reflected by clouds?
17%
How does the earths tilt affect global heat budget?
Polar regions have months over winter where they receive no insolation at all whereas the tropics receive high insolation all year round.
Describe the ocean current in the North Atlantic
clockwise gyres (loops) due to the coriolis effect
Warm currents travel towards the poles
Cold currents return cool water from the poles
What % of insulation is reflected by atmospheric gases and dust?
8%
What % of insulation is reflected by Earths surface?
6%
What % of insulation is absorbed by the Earths surface?
46%
What 5 of insolation is absorbed by the atmosphere?
23%
How does Latitude affect the global heat budget?
the curvature of the earths surface means that solar energy is much more concentrated at the tropics giving higher insolation.
How does Albedo affect the global heat budget?
high reflectivity means less insolation (the poles) low reflectivity means more insolation (the tropics due to rainforests etc)
How does the atmosphere affect the global heat budget?
energy travels through the atmosphere and can be reflected. at the poles, energy travels through the atmosphere at an angle increasing the chance of it being absorbed or reflected
Explain the Hadley cell
Warm air rises at the equator forming an area of low pressure.
As it enters the upper atmosphere it spreads out to 30 N and S.
It cools, sinks and returns as sub-tropical high pressure.
It then returns to the equator in the lower atmosphere as the easterly trade winds.
Hadley cell is thermally direct because it is driven by rising/falling air.
Explain the Polar cell
Cold air sinks at the poles forming an area of high pressure.
Air moves along the Earth’s surface towards the equator as polar easterlies.
When it reaches 60 N or S it has warmed enough to rise forming temperate low pressure.
It then returns to the poles in the upper atmosphere
Polar cell is thermally direct because it is driven by rising/falling air.
Explain the Ferrel cell
Located between the polar and Hadley cells.
Ferrel cell is thermally indirect because it is driven by friction.
Air sinks at 30 N and S and rises at 60 N and S.
What is Thermohaline circulation?
the movement of seawater in a pattern of flow dependent on variations in temperature, which give rise to changes in salt content and hence in density.
How are ocean currents affected by prevailing winds?
