Post on 12-Jan-2016
description
Energy Budget of the Earth-Atmosphere System
Energy Transfer
• Conduction -- direct molecular transfer
• Convection -- fluids; air or water– Sensible heat (temperature)– Latent heat (evaporation/condensation)
• Radiation -- no transfer medium
Adiabatic Processes
Energy associated with phase changes
Global Energy Balance
Inputs = Outputs
As the distance from the Sun increases, the intensity of the
radiation diminishes in proportionto the distance squared (inverse square law).
The solar constant is the amount of solar energy received by a surfaceperpendicular to the incoming rays at the mean Earth–Sun distance
and is equal to 1367 W/m2.
Radiation Laws
Stefan-Boltzmann Law
E = sigma T (4th power)
Wien's Law:
Wavlength Max - inversely proportional to the temperature
Incoming solar radiation available is subject to a number of processes as it passes through the atmosphere. The clouds and gases of the
atmosphere reflect 19 and 6 units, respectively, of insolation back tospace. The atmosphere absorbs another 25 units. Only half of the insolation available at the top of the atmosphere actually reachesthe surface, of which another 5 units are reflected back to space.
The net solar radiation absorbed by the surface is 45 units.
InfraRed Image
Latent Heat Transfer
Sensible Heat Transfer