Description

Homogenitus are clouds that are produced by human activities. Examples of homogenitus cloud include aircraft contrails, clouds that form from industrial emissions or smoke stacks, and clouds that form overtop of power plant cooling towers.

Homomutatus are clouds that formed due to human activities, and then underwent a change to a different kind of cloud. The best example of this is persistent contrails, which occur when aircraft contrails form in air that contains enough humidity for them to persist and grow, spreading out into cirrostratus or cirrocumulus clouds.

Both of these types can be seen in the image below. The thinner, more distinct contrails are the more recent homogenitus. The less distinct cloud in the distance, and at the top of the picture, are the homomutatus clouds formed as the contrails develop into more widespread cirrus clouds.