Ocean Mixing at Oregon State University

The distributions of heat, salt and chemicals (including pollutants) are critical to the intensity of ocean currents, to long- and short-term climate variations, and the health of our environment. Each is injected into the ocean at various rates and at various global locations. Mixing in the ocean acts to smooth distributions of these properties and to reduce concentrations of pollutants to tolerable levels. Understanding how mixing occurs and at what rates it proceeds is important to understanding how the oceans work, and is especially needed before accurate numerical models of the ocean can be developed.

A towed instrument package (MARLIN) being put in the water off the Oregon coast. The hull, which houses instrumentation and sensors developed and constructed at COAS, is a converted aircraft wing tank.

In the deep ocean, turbulence is weaker and the physics leading to mixing less well known. Numerous measurements indicate that deep turbulence is too weak to mix the water the way it appears to be mixed in the deep ocean. The search for the mechanisms of deep mixing is now one of the most important research areas in oceanography. One possibility we are investigating is that the deep water is mixed at the ocean's boundaries, where turbulence is strong, and then transported away from shore and to depth by processes that are not yet understood.

Turbulence studies at Stonewall Bank near Newport Oregon, involve a variety of measurements and instruments. The background image represents turbulence observed over the bank - red denotes turbulence levels several orders of magnitude larger than blue, a result of currents flowing from right to left over the bank.

 

Undergraduate level introduction to

Upper Ocean Mixing Download PDF (0.7MB)
Turbulence Physics Download PDF (1.4MB)

Research in Ocean Mixing at COAS is funded by the National Science Foundation and by the Office of Naval Research