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15 Cards in this Set
- Front
- Back
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Stefan Boltzmann's Law |
energy flux density is a function of the fourth power of the absolute temperature. See equation 1.3 or 1.4 E = ε σ T4
describes the total energy radiated by a body at a given temperature i.e., the area under the curve. The warmer a body is, the larger the area under the curve is |
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Kirchoff's Law |
absorptivity = emissivity |
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Planck's Law |
energy flux density per unit wavelength emitted by a blackbody as a function of its absolute temperature |
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Wien's Displacement Law |
wavelength of maximum emission is related to the absolute temperature of the radiating body. See equation 1.5. λmax =2.88x103/T |
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Net Radiation: |
Q* = K * + L *
Q* = QH + QE + QG
Exact partitioning of Q* into the other Qs depends on the surface type and the ability to transport heat (energy). The microclimates are determined by this. The preferred order of dissipation of energy is first by evaporation (QE, latent heat) then the other fluxes – sensible and ground (soil) heat flux. |
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K_down |
varies with the sun, is at a maximum near noon, minima at sunrise and sunset |
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K_up |
is a function of albedo and is a weak mirror image of K_down by convention K_up is negative, K_down is positive |
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L_down |
is constant over the course of the day, a function of air temperature |
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L_up |
is a function of surface temperature varies with K. Note: same sign convention as K |
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Q* |
- varies with K_down, by day Q* = K* + L* by night Q* = L* |
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Q* = QH + QE + QG |
Over moist, bare, soil Q* is dominated by QE (latent heat). QH (sensible heat) is present but small, QG (soil heat flux) is also present but positive early in the day as the soil absorbs energy. QG becomes negative by evening as the now warm, soil releases that energy to the atmosphere. |
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Properties of water |
- high heat capacity - latent heat of fusion - latent heat of vaporization |
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P = E + R + change in storage – in the short term |
short term change – flood, storage in reservoir, groundwater |
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P = E + R – in the long term |
over the long term storage is depleted to zero |
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FLUX |
=Ax G where A is the ability to transfer and G is the gradient |
