For opaque volcanic and meteorological
clouds, all of the emitted thermal energy
from the surface underlying the cloud is
absorbed by the cloud. The radiance
recorded by the satellite sensor is only
that which is emitted by the cloud. The
band 4 radiance is greater than the band
5 radiance, which results in a positive
band 4 minus 5 brightness temperature
difference. Most of the earth's surface
(water, land, snow, etc..) has a positive
band 4 minus 5 temperature difference.
This page maintained by Dave Schneider (djschnei@mt
u.edu)