From Cumulus to Cirrus: Exploring the Diversity of the Sky

3. Cirrus: The Feathery Sky Wisps

Often at 20,000 feet, high above the surface of Earth, cirrus clouds create exquisite brushstrokes across the sky. The very cold temperatures at high altitudes cause these thin, wispy clouds to be formed just of ice crystals. Their name, which comes from the Latin phrase for "curl of hair," fairly captures their feathery look, which sometimes resembles strands of hair or horse tails streaming over the blue canvas of the sky. Often heralders of changing seasons, cirrus clouds Although they usually imply fair weather in the near run, the presence of cirrus clouds can signify a coming weather system, therefore maybe bringing precipitation within the following 24 to 48 hours. For meteorologists trying to forecast weather changes, their movement can also offer useful hints about high-altitude wind patterns, therefore guiding their work. There are several kinds of these clouds, each with unique traits. For instance, the hooked ends of Cirrus uncinus give them an arresting look. Built by wind shear, cirrus kelvin-helmholtz clouds resemble frozen waves, broken in the sky. Usually running from horizon to horizon, cirrus radiatus clouds are set in parallel bands. The potential of cirrus clouds to produce magnificent optical events is among its most amazing features. The complex refraction and reflection of sunlight by the ice crystals forming these clouds produces stunning displays like halos around the sun or moon. Both scientific research and mythology have centered on these halos, which seem as brilliant circles of light. The dynamics of the top atmosphere are intimately related to the development of cirrus clouds. Usually forming at the leading edge of warm fronts, they arise where moist air is suddenly chilled at great elevations. Strong winds aloft then shapes the resultant ice crystals to provide the distinctive wispy, streaked look of cirrus clouds.