November 14, 2013
NASA Satellites Paint Detailed And Dynamic Picture Of Great Lakes Ice Cover
[ Watch the Video: A Better Way To Monitor Great Lakes Ice Cover ]
redOrbit Staff & Wire Reports - Your Universe OnlineScientists from NASA and the National Oceanic and Atmospheric Administration (NOAA) looked to the stars for inspiration as they developed a new technique that can be used to monitor the ice cover of the Great Lakes.
The technique, which was developed by Son Nghiem of NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California and George Leshkevich of the NOAA's Great Lakes Environmental Research Laboratory in Ann Arbor, Michigan, is said to be accurate enough to pinpoint a narrow channel of open water cut by an icebreaker during the nighttime.
“In the dark, it's difficult to read a map that's right in front of you,” Nghiem explained in a statement Wednesday. “Yet we now have a way to use satellite radars almost 500 miles [800 kilometers] out in space to see through clouds and darkness and map ice across the Great Lakes.”
The technique uses a dictionary that is able to translate binary digital data collected by satellite radar instruments onboard the Canadian Space Agency's RADARSAT-1/2, the European Space Agency's (ESA) European Remote Sensing Satellite 2 (ERS-2), and Envisat to identify and map different ice types on the lakes, the researchers explained. That dictionary was created by combining each type of ice observed with a series of unique radar signatures measured on the Great Lakes using radar equipment designed at JPL.
Ice on these bodies of water could damage both American and Canadian economies by impacting shipping and fishing. Furthermore, ice jams can become a public safety issue by causing flooding, and can adversely affect the environment and the ecology in the region as well.
While previous satellite observation-based techniques sometimes misidentified water as ice and vice-versa, the new method described in the latest edition of the Journal of Great Lakes Research reportedly corrects the issue. Furthermore, Nghiem and Leshkevich claim that is provides a more accurate analysis of ice characteristics, including its density and whether or not it has melted and refrozen.
According to Leshkevich, the method has been handed over to the NOAA, and the organization plans to use it to generate maps across the Great Lakes that will “provide important information for environmental management, ice forecasting and modeling, off-shore wind farm development, operational ice-breaking activities in support of winter navigation, and science research,” including an analysis of the area’s response to climate change.
Image 2 (below): A color-coded image of major ice types on Lake Superior, made from a RADARSAT1 radar backscatter image using a new NASA and NOAA-developed technique. Credit: NOAA Great Lakes Environmental Research Laboratory and NASA/JPL-Caltech