Atmospheric heat budget Flashcards
How does the earth receive energy
solar radiation, some is lost in the atmosphere but overall there is a net gain
Why does not all radiation reach the earth
absorbed in atmosphere by dust, ozone, co2 etc
How much radiation actually reaches the earths surface
24% with the rest being lost to absorption, scattering and reflection
How is the earth heated
sort wave radiation is converted into heat energy which warms the surface with long wave radiation reflected back into the atmosphere however it can become trapped due to greenhouse effect
Physical reasons the amount of energy received may vary
solar constant
latitude: equatorial regions receive greater as approaches head on while at poles approaches at an oblique angle
distance from the sun
Tilt of the earth: 23.5 degree tilt means at 66.5 N and S times when receive no insolation
How is the imbalance in the energy budget solved
Atmospheric movement and vertical heat transfers
How do atmospheric movement help
80% transferred from tropics by winds
20% transferred by ocean currents
How do vertical head transfers work
Energy transferred from warmer areas by radiaton, convection and conduction.
Latent heat also transfers from positive areas of budget
A long term factor affecting insolation is altitude of land how does that work
insolation heats the land by warming air above by conduction, higher land has less dense air which adds to cooling affect as the ELR is 6.4 degrees per 1000m
Another long term factor is altitude of the sun
Higher latitudes sun has to pass through more atmosphere so is absorbed and scattered at a greater rate
How does the land: sea affect insolation on a long term
land heats quicker than the sea as water has a greater specific heat capacity therefore in summer land heats rapidly while oceans heat at a slower rate but in winter are able to retain heat meaning coastal areas have smaller temp ranges
