The 12.0 µm Channel 5 imagery is similar to that from Channel 4 (10.7 µm), except that this wavelength has a unique sensitivity to low-level water vapor.   Used alone, it often appears identical to the Channel 4 imagery (see example below).   However, when combined with the corresponding Channel 4 data, the subtle differences between them can be used to help the forecaster identify low-level moisture fields (as will be discussed further in the following section on Combined Image Products).

  This example shows a Channel 4 and a Channel 5 image of the same scene at the same time.   [Click on the "Forward" button to begin an automated sequencing between the two, or alternatively, click alternately between the "+1" and the "-1" buttons for a slower pace.]   As you can see, the two are nearly indistinguishable.