5. The global heat budget Atmosphere 23% absorbed by atmosphere 46% absorbed by the surface 17% reflected by clouds 8% reflected by atmospheric gases and dust 6% reflected by surface 100% Solar Energy (short wave)
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9. Energy Receipt with Latitude Factors which influence climate on a global scale
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11. Tropical latitudes receive more solar radiation than the polar latitudes for 3 main reasons. In Polar regions the radiation has to penetrate a greater depth of atmosphere (absorbs more heat). The same amount of solar energy is received over a much greater area in Polar regions (less heating). High energy loss at poles because of ice cap albedo. Equator (0 º) North Pole South Pole
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13. Albedo of various surfaces 5 - 10 Forest 15 - 25 Dry Soil 25 - 30 Grass 20 - 30 Sand (Beach or Desert) 50 - 60 Old Snow 80 - 85 Fresh Snow % Reflected Surface
14. What does this mean? 90 ºN 60 ºN 30 ºN Equator 0 º 30 ºS 60 ºS 90 ºS 0 100 200 300 Insolation (Joules) Latitude 35 ºN 35 ºS Terrestrial Radiation Insolation There is a net gain (surplus) of energy in Tropical areas because incoming radiation exceeds outgoing radiation. However in polar areas there is a net loss (deficit) of energy because outgoing radiation is greater that incoming radiation.
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16. 90 ºN 60 ºN 30 ºN Equator 0 º 30 ºS 60 ºS 90 ºS 0 100 200 300 Insolation (Joules) Latitude 35 ºN 35 ºS Energy Surplus Energy Deficit Energy Deficit However, energy is transferred from areas of surplus (Tropics) to areas of deficit (Poles) by atmospheric circulation and by ocean currents.