$400,000 Navy Grant Funds Ocean Turbulence Research At SMAST

DARTMOUTH, MA. - Armed with a free-swimming submersible robot, a University of Massachusetts Dartmouth oceanographer at the School of Marine Sciences and Technology (SMAST) is embarking on a three-year study of the elusive relationship between small-scale water movements and small-scale ocean life.

DARTMOUTH, MA. - Armed with a free-swimming submersible robot, a University of Massachusetts Dartmouth oceanographer at the School of Marine Sciences and Technology (SMAST) is embarking on a three-year study of the elusive relationship between small-scale water movements and small-scale ocean life. 

Funded by the Office of Naval Research, SMAST Professor Louis Goodman and his collaborators will be participating in the Navy’s $9 million LOCO Program field experiments. ‘LOCO’ stands for Layered Organization in the Coastal Ocean, a phenomenon recently discovered in near-shore environments. 

“The LOCO program is aimed at understanding why and how extremely thin and dense layers of biological organisms can exist in the ocean,” says Professor Goodman. “From my perspective as a physical oceanographer, I am trying to understand how these layers can form in an environment which is often turbulent.” 

“By understanding water movements in the ocean, we can track a range of particles, from suspended sediment to droplets from an oil spill,” Goodman says. “But the ‘living particles’, or plankton, which make up these layers are not completely controlled by waves, currents, and tides. Plankton can have the power of self-propulsion and a kind of buoyancy control, so their relationship to their local flow field is not straightforward.” 

The density of organisms in these so-called “thin layers” can be 1000 or more times greater than in the water just above and below the layers. Such a concentration of biomass markedly changes the properties of the ocean where the creatures congregate. For example, the passage of light and sound through the water column can be altered by the dense layer. So, in addition to changing the environmental conditions, these layers distort some of the very media characteristics on which oceanographers rely for measurements. 

Focused study of thin layers is in its infancy. Most of what is known about them was gathered from studies in a single fjord in the Pacific Northwest. However, evidence of thin layers has been noted in a number of other locales, including Monterey Bay and the southern California coast, near-shore regions of the South Atlantic Bight, the west Florida shelf, and the Oregon shelf. 

Goodman’s field observer will be an 80-lb., torpedo-shaped autonomous underwater vehicle, called REMUS, which he acquired under a separate grant last year. Created by Woods Hole Oceanographic Institution researchers and commercially developed by Hydroid, Inc., the REMUS will be specially equipped for this study with physical, acoustic, and optical instrumentation to measure the smallest scales of physical variability (turbulence) in coastal waters. 

Why a robot vehicle to serve as the project’s eyes and ears? “We face the same kind of decisions that NASA faces,” points out Goodman. “Humans are versatile observers, but transporting them and caring for them in an exotic environment, like at sea or in space, is challenging and expensive. We’ve made great strides with autonomous vehicles, and now they’re making possible projects which might otherwise be prohibitively costly or risky.” 

Goodman will be joining research colleagues from the University of Rhode Island, Oregon State University, Woods Hole Oceanographic Institution, the University of California at Santa Cruz, and others in the LOCO program. 

Additional information about this project or the UMass School of Marine Sciences and Technology is available through the Internet at http://www.smast.umassd.edu or by calling Dr. Goodman at 508-999-6375. 


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