CLOUDS - The wild card of Climate change .
"The scientific community is uncertain about how the effects of clouds will change in the future," says Hugh Morrison, a scientist at the National Center for Atmospheric Research (NCAR) in Boulder, Colo.
As clouds continually change and dance across the horizon, they invariably create a mesmerizing, ethereal mystique.
But many of the very same characteristics that give clouds their mesmerizing mystique also make them vexing, perplexing and difficult for scientists to study. These characteristics include their ephemeral, short life-spans, constant motion, ever-changing shapes, wispy, heterogeneous structures and high altitudes; clouds may reach 12 miles or more above the Earth.
Another factor that helps shroud clouds in mystery is their status as multi-scale phenomena. That is, the behavior of clouds is determined by complex phenomena operating at a wide range of scales, including:
- cloud particles that are fractions of a millimeter across
- individual clouds that are a few kilometers in diameter
- cloud systems that range over many kilometers
- weather systems that cover many thousands of kilometers.
What's more, cloud phenomena that occur on any particular scale may influence cloud phenomena occurring at other scales. For example, large-scale cloud movements, which are controlled by factors such as wind and turbulence, affect micro-processes, such as the formation of rain droplets, snow and hail, the speed at which these forms of precipitation fall, and their changing shapes.