Satellite Captures Unusual ‘Cloud Streets’
Nancy Atkinson at Universe Today reports on rare cloud formations, which a NASA satellite photographed over Hudson Bay, Canada on November 20, 2011 at 12:25 p.m. EST (17:25 UTC).
Cloud streets are long lines or bands of cumulus clouds that usually form within the lower one to three kilometers of the atmosphere, and come from eddies in the atmosphere.
According to NASA’s Earth Observatory and the Goddard Space Flight Center Flickr page, cloud streets form when cold air blows over warmer waters, while a warmer air layer – or temperature inversion – rests over top of both. The comparatively warm water of Hudson Bay gives up heat and moisture to the cold air mass above, and columns of heated air – thermals – naturally rise through the atmosphere. As they hit the temperature inversion like a lid, the air rolls over like the circulation in a pot of boiling water. The water in the warm air cools and condenses into flat-bottomed, fluffy-topped cumulus clouds that line up parallel to the wind.
Read more at Universe Today.