Atmosphere Flashcards
Global heat budget
The Earth’s surface only absorbs about 50% of solar energy because reflection and scattering reduces the amount of energy by about about 31%. This energy is sent back into the atmosphere as long wave radiation. Reflection therefore varies depending on cloud cover and the covering of the earth’s surface. This is known as the albedo effect. For example, snow at the poles reflects more radiation compared to darker forest areas which absorb more incoming radiation. About 17% is reflected by clouds and 8% is scattered by gas and dust particles, whilst 6% is reflected from the earth’s surface. Absorption by the atmosphere reduces the solar energy by approximately 19%. This is because 17% is absorbed by dust and gases, whilst 3% is absorbed by clouds.
Why theres a surplus of solar energy in tropical latitudes and a deficit of solar energy towards the poles.
There is a surplus of solar energy in the tropical latitudes as this is where the Sun’s rays are more concentrated. The Sun rays strike these areas at right angles; therefore the intensity of insolation is at its greatest. Suns angle is in the sky decreased towards the poles due to the curvature of the Earth, which spreads heat energy over a larger surface area. Therefore the Sun’s rays have less atmosphere to pass through other tropics, so less energy is lost absorption of reflection by clouds, gas and dust. Tilt of the axis results in the sun being higher in the sky between tropics throughout thr year, focusing energy. No solar insolation at the poles for 6 months of thr year, producing 24 hour darkness so the tropics receive much more insolation throughout the year. The albedo effect also makes a difference. More radiation is absorberf at the tropics due to the vadt amount of dark foresrty, e.g. the Amazon Rainforest.

3 cell model
The Coriolis force causes northern hemisphere Winston deflect to the right, and the southern hemisphere ones to the deflect to the left. The equator has a surplus of energy as it is the hottest part of the Earth, so the air is warm in there and less dense. The warm air rises into the atmosphere, causing low pressure, and then travels to 30° north and south, with a temperatures are lower saw the air cools and sinks. He returns to the equator, completing the Hadley cell. The polar cell also be distributes energy. Bear at the poles is very cold on the dance and therefore sinks, causing high pressure. When is sinks to the surface it spreads out as wind (polar easterlies) To where it is then warmed by the Earth surface and rises at 60° north and south. Then spreads out in the upper atmosphere and move pole words, completing the Polar cell. Finally, some of the air that sinks to 30° spreads towards the poles are as wind (south Westerlies) and meets cold air from thrnpoles at 60°. The warm air rises over the cold air and kills and I put atmosphere what does spreads north and south. This completes the ferrel cell.
Ocean currents
currents follow loops organisers, and move clockwise in the northern Atlantic. Warm currents travel from the equator towards the poles, for example the North Atlantic drift. cold currents return cool water from the poles
The Coriolis force deflects currents to the right in the northern hemisphere, and to the left in the southern hemisphere. Ocean currents are greatly influenced by prevailing winds. Due to differing salinity levels density differences occur in water, resulting in chilled polar water little water sinking spreading towards the equator and displacing warm water pole wards
