SATELLITE DATA AND ICING ALGORITHM
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These data are from the new GOES-8 satellite, a geostationary
satellite which gives high quality visible, infrared and other
images of the United States and the surrounding region.

Visible satellite images are simply what would be seen by the
naked eye if one were to look at the Earth from outer space. 

Infrared satellite images give a measure of the infrared energy
emitted from clouds and the Earth below, which is a function of
temperature.  The data field is then converted to temperature,
and plotted.  The temperature indicated will be that of the hightest
cloud top or the earth's surface (if no clouds are present).

The icing product is a bit too complicated to describe in detail here, 
so I urge those who are interested to read the references indicated 
at the bottom of this page to get a full explanation of this product.  
In general, what you see are clouds tops which have radiative patterns 
that are indicative of liquid water at temperatures between -25 and
0 degrees C.  These "supercooled liquid cloud tops" indicate those
clouds which are likely to contain icing conditions.  One caution
with this algorithm is that low altitude supercooled liquid cloud 
tops can be obscured by higher level clouds which are at temperatures 
below -25C, such as cirrus clouds.  Also, deep convective clouds
may contain significant amounts of liquid water, but have cold cloud
tops.


References
----------
Thompson, G., T.F. Lee and J. Vivekanandan, 1997: Comparisons of
satellite-based aircraft icing diagnoses.  To be presented at and
included in the preprints for the 7th Conf. on Aviation, Range and
Aerospace Meteorology, 2-7 February, Long Beach CA, Amer. Meteo.
Soc.

Vivekanadan, J., 1997: Aircraft icing detection usign satellite and 
radar observations.  To be presented at and included in the preprints 
for the 7th Conf. on Aviation, Range and Aerospace Meteorology, 
2-7 February, Long Beach CA, Amer. Meteo. Soc.