For transparent clouds, the radiance
recorded by the satellite sensor is a
combination of the radiance of the cloud,
and the radiance of the underlying
surface. For meteorological clouds, the
absorption of the of energy from the
underlying surface is greater in band 5
than in band 4, due to a larger refractive
indices for water and ice particles in the
band 5 region than in the band 4 region.
This results in a positive band 4 minus 5
brightness temperature difference.
This page maintained by Dave Schneider (djschnei@mt