Airborne sensor to study 'rivers in the sky'
They're called atmospheric rivers -- narrow regions in Earth's atmosphere that transport enormous amounts of water vapor across the Pacific or other regions. Aptly nicknamed "rivers in the sky," they can transport enough water vapor in one day, on average, to flood an area the size of Maryland 0.3 meters (1 foot) deep, or about seven times the average daily flow of water from the Mississippi River into the Gulf of Mexico. The phenomenon was the subject of a recent major emergency preparedness scenario led by the U.S. Geological Survey, "ARkStorm," which focused on the possibility of a series of strong atmospheric rivers striking California -- a scenario of flooding, wind and mudslides the USGS said could cause damages exceeding those of Hurricane Katrina in 2005.