Regional And Mesoscale Meteorology Team
Daily Satellite Discussion
Monday December 15, 1997
Figure 1 is the 10.7 um image over Quebec last night. Typically the yellows and reds are associated with clouds, but here some of what is colored yellow and red is clear ground. Figure 2 is the corresponding fog product image. It indicates some clouds in western Quebec and hints that much of Quebec may be free of clouds, as seen by the gray shades. These gray areas are affected by the noise at 3.9 um, however, so positive identification is difficult. Figure 3 is a 10.7 um image with gray shades only. In this image, some of the lakes and rivers in Quebec are more easily seen than in the other images, again, suggesting clear skies.
The best way to distinguish cold, clear ground from clouds is to view an image loop of the area. Below are links to loops of the three products discussed above. Using the loop of 10.7 um imagery with the color enhancement shows the area that is cold and clear from those areas covered by clouds-the clouds move rapidly, whereas the clear ground may expand or contract, but won't move. The loops of the other two products are also more helpful than the single images. Of course visible images are important during the day.
Color enhanced 10.7 um loop
Fog product loop
Gray scale 10.7 um loop