In the gray-scale region of the scale, brighter clouds are coldest. The mid-infrared channel is unique in that is portrays some emitted and some reflected energy. The image can be interpreted much like the thermal infrared image with colder cloud tops extending higher into the atmosphere. This wavelength is often used for identification of low-level moisture, determination of sea surface temperature, and detection of airborne dust and volcanic ash. The water vapor images are useful in determining areas of moist air and dry air in the upper atmosphere.
Darker colors represent drier air while bright colors represent moist air.
Large areas of moist air in the upper atmosphere is often associate with areas of convective activity. The physical properties of this wavelength make this image useful both night and day. The maximum resolution of the visible channel on the GOES satellites is 1km. The remaining channels have a maximum resolution of 4km. Since the visible channel resolution is 1km, the resultant image is very large.