NASA helps melt secrets of Great Lakes ice

Nov 14, 2013 by Carol Rasmussen
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

(Phys.org) —Two scientists from NASA and NOAA have developed a new space-based technique for monitoring the ice cover of the Great Lakes that is so accurate it can identify a narrow channel of open water cut through the ice by an icebreaker—even at night.

"In the dark, it's difficult to read a map that's right in front of you," said Son Nghiem of NASA's Jet Propulsion Laboratory, Pasadena, Calif., one of the developers of the new technique. "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 across the Great Lakes."

Ice on the Great Lakes puts a big chill on the U.S. and Canadian economies, affecting shipping, fishing and also public safety when winter and spring flooding are caused by ice jams. It has a significant impact on the regional environment and ecological systems as well. Yet previous techniques of analyzing satellite observations of the ice sometimes misidentified ice as water and vice versa.

The new method, co-developed by Nghiem and his colleague George Leshkevich of NOAA's Great Lakes Environmental Research Laboratory, Ann Arbor, Mich., not only corrects that problem, it also gives a more accurate analysis of ice characteristics, such as whether the ice is dense or full of bubbles, and whether it has melted and refrozen.

The method uses a special dictionary that translates binary digital data from satellite radar instruments on the Canadian Space Agency's RADARSAT-1/2, the European Space Agency's European Remote Sensing Satellite 2 (ERS-2), and Envisat to identify and map different types of ice over the Great Lakes. The researchers compiled the dictionary by pairing each observed ice type to a library of unique radar signatures that were measured on the lakes using a JPL-developed advanced radar aboard a U.S. Coast Guard icebreaking ship.

Leshkevich said the method has now been transitioned to NOAA for routine use in generating ice maps across the Great Lakes. "These maps will provide important information for environmental management, ice forecasting and modeling, off-shore wind farm development, operational icebreaking activities in support of winter navigation, and science research."

The more accurate classification of ice will also be useful for scientific research into such questions as how the Great Lakes are responding to, and leading, climate change in the upper Midwest.

Explore further: CryoSat maps largest-ever flood beneath Antarctica

More information: www.iaglr.org/jglr/release/39/2013.05.003_leshkevich.php

add to favorites email to friend print save as pdf

Related Stories

CryoSat maps largest-ever flood beneath Antarctica

Jul 02, 2013

(Phys.org) —ESA's CryoSat satellite has found a vast crater in Antarctica's icy surface. Scientists believe the crater was left behind when a lake lying under about 3 km of ice suddenly drained.

Image: Upsala glacier retreat

Nov 05, 2013

This photograph by an astronaut on the International Space Station highlights the snout of the Upsala Glacier (49.88°S, 73.3°W) on the Argentine side of the North Patagonian Icefield. Ice flow in this glacier ...

Earth from space: Ice in motion

Oct 04, 2013

Clouds blur our view of the snow below in parts of this image acquired over the southern tip of Greenland by the Landsat-8 satellite on 30 May.

Giant channels discovered beneath Antarctic ice shelf

Oct 06, 2013

Scientists have discovered huge ice channels beneath a floating ice shelf in Antarctica. At 250 metres high, the channels are almost as tall as the Eiffel tower and stretch hundreds of kilometres along the ...

Lake Erie algae, ice, make a nice mix in winter

Jan 11, 2012

Clarkson University Biology Professor Michael R. Twiss has been working with colleagues and students from Ohio, Pennsylvania, Tennessee and Ontario, to study Lake Erie over the past five winters during mid-winter, ...

Recommended for you

Magnitude-7.2 earthquake shakes Mexican capital

Apr 18, 2014

A powerful magnitude-7.2 earthquake shook central and southern Mexico on Friday, sending panicked people into the streets. Some walls cracked and fell, but there were no reports of major damage or casualties.

User comments : 0

More news stories

China says massive area of its soil polluted

A huge area of China's soil covering more than twice the size of Spain is estimated to be polluted, the government said Thursday, announcing findings of a survey previously kept secret.

UN weather agency warns of 'El Nino' this year

The UN weather agency Tuesday warned there was a good chance of an "El Nino" climate phenomenon in the Pacific Ocean this year, bringing droughts and heavy rainfall to the rest of the world.

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...