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atmosphere - Coggle Diagram
atmosphere
describe and explain how the pattern of ocean currents helps to redistribute energy across the globe.
in the north Atlantic ocean the warm water from the north equatorial current is driven westwards by the north east trade winds and deflected to the right by the Coriolis force
on meeting the cost of Mexico the north equatorial current is deflected north feeding into the gulf stream
the gulf stream is driven towards western Europe by the westerlies because planetary winds move in a north easterly direction from the subtropical high pressure belt.
on approaching the land mass of Europe the current splits; some continues to flow northwards as the north Atlantic drift and warms western Europe whereas some is deflected southwards down the west coast of Africa as the cold canary current
this feedbacks into the north equatorial current completing the gyre. the Labrador current brings cold water from the artic down to the west coast of north America
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explain why only 50% of the solar energy reaching the edge of the atmosphere reaches the earths surface.
26% of short wave energy is reflected back into space. This is because 6% is reflected by reflected by atmospheric gasses and dust, and 20% is reflected by clouds due to the upper white surface of clouds being very reflective.
18% of the solar energy is absorbed by the atmosphere and transformed into heat. This is because 3% is absorbed by clouds and 15% is absorbed by gasses, including water vapour and dust.
44% of the earths solar energy is reflected or absorbed by the atmosphere only the remaining 56% reaches the earths surface. however only 50% actually ends up reaching the earths surface because 6% is reflected back off the surface into space.
overall in the global heat budget system 68% of solar energy is absorbed and transformed into heat and 32% is reflected.
Reflected heat, in the form of long-wave radiation, is trapped in our atmosphere and keeps our planet warm. This is known as the natural greenhouse effect.
the proportion of the solar energy reflected by the earths surface is due to the albedo effect and varies according to color and texture of the surface.
Explain with an aid of diagrams why tropical latitudes receive more solar energy than polar regions.
tilt: the poles spend 11 weeks of the year receiving no solar energy at all. in the north pole that is January to November. whereas in the tropical latitudes they receive intense solar insulation all year round because the earth tilt has less significance between the tropic of cancer and Capricorn.
albedo: the poles are covered in snow and ice which means that 80% of the solar insulation that reaches the earths surface is reflected. whereas in the tropical latitudes the albedo is much less as the dark forest's and oceans absorb most of the solar radiation that reaches its surface.
atmosphere: at the poles the insolation has to pas through a thicker layer of atmosphere than at the tropics. this is because the suns rays approach the poles at an oblique angle due to the curvature of the earth causing more of the incoming solar energy to be reflected or absorbed by the earths atmosphere resulting in less reaching the earth surface.
curvature: at the poles the isolation is spread over a greater surface area that in the tropics where it is focused on a smaller area. this is because the suns rays are more concentrated in the tropical latitudes where the intensity of the insolation is at its greatest when the suns rays strike vertically.
explain how the atmospheric circulation helps to redistribute energy around the world via Hadley, polar and Ferrell cells
at the polar cells the air is cold due to a lack on insulation. this cold air sinks towards the midlatitudes. the polar easterlies blow cold air from the polar high pressure belt towards the more temperate low pressure belt where the air meets creating a zone of convergence, forcing the air to rise.
in between the other two cells is the Ferrell cells which are thermally indirect. this is because unlike like the other two cells they are not driven by heat from the sub but instead the movement of the other two cells. the westerlies blow relatively warm air from the subtropical high pressure belt to the temperate low pressure belt. this causes cold air from the poles to move towards the equator and warm air from the equator to move poleward.
the Hadley cells are located 5 degrease north and south of the equator and an area of intense isolation creating an energy surplus. At around 11km up in the atmosphere the air cools and diverges. the trade winds blow relatively cool air from the subtropical high pressure belt towards the equatorial low pressure belt. the cool air sink back towards the earths surface under high pressure conditions.
it is in this way that cells move energy from areas of surplus to areas of deficit, redistributing the energy across the globe.