Water Vapor Channel (6.40-7.08)

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

• 6.7 microns.  Notice that most of the radiance received by the satellite comes from very cold temperatures (approximately 240-260 K).  
• This is because water vapor is a very active absorber in that portion of the spectrum.  Thus, any radiation reaching the sensor comes from emission of water vapor that is in the mid-upper troposphere.
• Weighting function - (see Ch 4, pgs 3-4 in COMET module on GOES Imager for review on weighting function) - The 6.7 micron channel maxes out at about 400 mb.  Hence, you are seeing mid-upper level water vapor with this channel.

• 8 km resolution
• Good for tracking flow in mid to upper troposphere.  Short waves are readily seen.
• The jet stream is also readily visible
• relatively noise free channel - makes it possible to do cloud tracking - gives cloud track winds.
• Weighting function peak at mid levels will shift vertically according to the distribution of water vapor in the atmosphere.
• Univerisity of Wisconsin Water Vapor Tutorial