Fog in the Rockies Valleys and Washington
Jeff Schmaltz, MODIS Rapid Response Team, NASA/GSFC
Thick fog clings to the lowlands of the northwestern United States and southern British Columbia in this Moderate Resolution Imaging Spectroradiometer (MODIS) image, taken on November 22, 2005, by the Aqua satellite. With fog covering the lowlands and the brilliant silvery-white snow-capped peaks of the Rocky Mountains rising into a clear sky, elevation change is easy to see in this image. In the photo-like natural color version of the image, the snow-covered mountain tops are a brighter shade of white than the fog. The mountains also stand out because of the blue shadows the peaks cast on their neighbors. The fog, by contrast, is a smooth blanket of white.
The false color image, created using light from the shortwave and near infrared part of the electromagnetic spectrum, provides a greater contrast between snow and fog. Snow is bright blue, while fog is pale blue and white. In this image, it is clear that the Rockies fork into two series of ranges near the border between the United States and Canada. One line of mountains extends down the center of Washington and Oregon and the other spreads across Idaho and Montana. In between the two mountain groups is a relatively open plain, which is fog-covered in this scene.