UMaine Researchers Launch Underwater Glider
Contact: Mary Jane Perry (207) 581-3321; David Munson (207) 581-3777
Mary Jane Perry, a professor of marine sciences and oceanography at UMaine’s Darling Marine Center and a pioneer in the use of autonomous underwater gliders for remote research, deployed the university’s first such glider into the chilly waters of the Gulf of Maine with the help of colleagues Neal Pettigrew and David Townsend in June. Affectionately dubbed Nemo, the six-foot, florescent yellow device promises to change the way we look at the ocean.
Autonomous gliders like Nemo represent a whole new way of carrying out ocean research. Looking like a cross between a torpedo and a manta ray, gliders are built for long-distance, low-energy travel. On its maiden voyage along the Maine Coastal Current, Nemo cruised along at just under one mile per hour, its multiple environmental sensors whirring away, twenty-four hours per day, seven days per week. The glider’s data gathering marathon continued for two weeks — less than half of its one-month trip length potential.
“One of the main advantages of gliders is their persistent presence in the ocean,” said Perry in a presentation to her fellow researchers in July. “They give us the ability to gather data and observe features over time that might never be observed using satellites or other platforms. If you have to wait for a ship, you might entirely miss an important event.”
Nemo’s ability to operate for an entire month at a time is due in part to its unique method of movement. Using an internal piston that alternately draws in and expels sea water from a chamber in the rear section of its tubular housing, Nemo changes its buoyancy by changing the ratio of internal seawater to oil, which is stored in a bladder in the nose of the device. The buoyancy changes are translated into forward motion with the help of its wings.
Nemo’s rhythmic rise and fall propels it, albeit slowly, through the water column. At set intervals it rises to the surface, transmitting data back to the lab on everything from phytoplankton concentration to salinity. It maintains a predetermined course by checking its position via GPS or it can accept new instructions from researchers working from a ship’s cabin or mainland lab.
Perry’s ultimate goal is to have two or more gliders operating in Maine waters, allowing researchers to maintain a constant stream of data by replacing active gliders on a monthly basis.
Utilizing funding from the Office of Naval Research and the UMaine Office of the Vice President for Research, Perry worked closely with UMaine School of Marine Sciences researchers Neal Pettigrew, David Townsend and Carol Janzen to acquire Nemo and initiate what they hope will become a long-term program of research utilizing multiple gliders.