Clouds and radiation in a LSM

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Clouds and radiation in a LSM
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Stratocumulus cloud albedo example
homogeneous stratocumulus cloud layer
cloud layer depth 400 m effective cloud
droplet radius 10 mm optical depth t 25
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Real clouds are inhomogeneous
Stratocumulus albedo from satellite
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Albedo for an inhomogeneous cloud layer
inhomogeneous stratocumulus cloud layer
Redistribute liquid water optical depths t
5 and 45
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Cloud albedo in a weather forecast or climate
model
Decrease optical thickness Cahalan et al (1994)
c 0.7 (FIRE I observations)
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Factor c depends on the optical depth variance
(st)
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Analytical results for the inhomogeneity factor
cAssumption Gaussian optical depth distribution
c isolines
c not smaller than 0.8
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Scattering and absorption
scattering cross section ssca
absorption cross section sa effective area of
the molecule for removing energy from the
incident beam
absorption cross section sa