Anibal Herrera
MPO 551 10/24/2011
The above image is a recent IR satellite picture taken of hurricane Rina just south
of Cuba. The purple coloring represents high (cold) cloud tops, the yellow represent
intermediate high (warmer) clouds, and the blue to white represent the low (warmest)
clouds. From this image one can deduce the vertical profile of the hurricane. Note that the
white clouds can easily be interpreted as low lying stratus clouds. The clouds marked by
the coloring are towering comolus/comolunimbus clouds with high altitude cold tops.
These clouds are highly active and related to the strongest forces of the storm.
In the infrared channel, the satellite senses energy as heat. The earth’s surface
absorbs about half of the incoming solar energy. Clouds and the atmosphere absorb a
much smaller amount. The earth’s surface, clouds, and the atmosphere then re-emit part
of this absorbed solar energy as heat. The infrared channel on the satellite senses this reemitted radiation at wavelengths between 10.5 and 12.6 micrometers. The lowest clouds
(e.g. fog) are often indistinguishable from the land/sea. The main advantage of infrared
over visable is that images can be produced at night, allowing a continuous sequence of
weather to be studied.