Start Date: End Date: Published Date Data Date
Data acquired December 1 - 1, 2002 900 x 1200 383 KB - JPEG
Data acquired December 1 - 1, 2002 1800 x 2400 1 MB - JPEG
Data acquired December 1 - 1, 2002 3600 x 4800 4 MB - JPEG
Thick fog and clouds can be difficult to distinguish from snow is true-color satellite imagery, because they all appear white. This pair of images from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite shows the value of multi-spectral analysis for teasing out the differences. While clouds, fog, and snow all look the same in visible spectral bands, they look different in other parts of the electromagnetic spectrum. In this false-color image, snow or ice crystals on the ground appear red, liquid water in the atmosphere appears white or peach, areas of low or no vegetation appear light blue-green,a nd the forested hills of the Rocky Mountains appear dark green. These images show (clockwise from upper left) British Columbia and Alberta, Canada; Montana, Idaho, Oregon, and Washington.
Jacques Descloitres, MODIS Rapid Response Team, NASA/GSFC
Published December 22, 2002 Data acquired December 1 - 1, 2002