High clouds are given surname of "cirro" or "cirrus." These clouds are ground at levels from 20,000 feet to 45, 000 feet. So you have cirrus clouds, cirrostratus, and cirrocumulus.

Cirrus clouds at the level of the jet stream – often about 6 miles (10 kilometers), above the ground – can sometimes move at over 200 miles per hour (320 kilometers per hour).

Cirrus clouds form much higher than cumulus clouds. They occur at elevations above 20,000 feet, where the temperature of the air is below freezing. Water droplets at this elevation freeze and form ...

If we ever get desperate enough to try artificially cooling the planet to slow global warming, we might want to think about modifying cirrus clouds. Thinning out these feathery, high-altitude ...