The formation of wispy cirrus clouds is not a simple matter. New research is revealing more about the conditions needed to generate these high-altitude ice clouds and illustrates new ways that pollutants can have consequences many kilometers up in the atmosphere.
Atmospheric scientists have known that when compounds such as sulfates dissolve in water droplets, those tiny airborne solutions can freeze and create cirrus clouds. Also, scientists have known that dust particles can serve as airborne platforms on which vapor freezes. Now, using vapor and particles harvested from the atmosphere, researchers have teased out more details about how cirrus clouds form.
A group led by Paul J. DeMott of Colorado State University in Fort Collins collected air samples at a lab at