10.7 micron channel (10.2-12.0)

http://www.meted.ucar.edu/satmet/goeschan/#

• 10.7 microns.  This is in the atmospheric window region.  Most of the radiation in this channel comes from near the surface of the earth or clouds near the earth's surface.   This channel is good for determining properties of the earth's surface.
• Weighting Function - At 10.7 microns, most the the radiance is from the earth's surface and clouds (like fog and low-level stratus), when present.

• 4 km resolution
• Little atmospheric attenuation at this wavelength, hence, satellite sees surface of earth.
• Also, emissivity for all objects except high cirrus is close to one at this wavelength, so their temperatures can be determined.  The brightness temperature of an object is determined by inverting the plank function:
• This channel is useful for tracking diurnal evolution of land and ocean temperatures.
• Stratus clouds have emissivity close to one, so most all of the long wave radiation is absorbed by them.  Hence, the cloud top temperatures can be found fairly well.
• Thick cirrus clouds also have emissivities close to one, but thin cirrus do not.  Hence, some of the long wave radiation passes through the thin cirrus.  As a result, thin cirrus will look warmer than thick cirrus.  Hence, thick cirrus clouds are used to determine cloud top temperatures.
• This channel can be used to estimate storm intensity (cloud top temps) and estimate rainfall.
• Enhancing the IR data can make interpretation much easier