Tri-spectral analysis of contrail and cirrus.

A simple cloud detection scheme suggests that contrails do have different spectral properties than natural cirrus in a similar environment. A scatter diagram of 8-11 micron versus 11-12 micron brightness temperature differences for two MAS scenes results in two distinct clusters. The red boxes are from a land scene overlaid with thin cirrus cloud at 15:52 UTC. The blue circles are points plotted from a MAS scene overlaid with a small amount of thin cirrus and a contrail (15:56 UTC). The points of thin cirrus located in the contrail scene fall along the same slope as the strictly cirrus scene. It is clear that the contrail has a brighntess temperature difference signature different from that of the natural cirrus.

MAS contrail image.

MAS cirrus image.