Ocean in a labBy Kelly Foss
Combine water, a rotating tank, a camera and a multicolor source of light and what do you get? An incredible blend of art and science.
Using this equipment, Dr. Iakov Afanassiev, a professor in the Department of Physics and Physical Oceanography, has developed a new and highly visual method of measuring the properties of fluids. Specifically, it has allowed him to create a model ocean in his lab.
“How do you do research in ocean sciences?” asked Dr. Afanassiev. “Well, you either go to the ocean and measure things there or you can use computers and run numerical models. The ocean is difficult and expensive to do measurements in, and although there has been a lot of progress in computer technology, all computer models are deficient in one way or another.”
A third method is laboratory experiments, which Dr. Afanassiev said have become less popular in recent years.
“Lab experiments deal with real fluid,” he explained. “For example, I use water. I add salt or heat it to make temperature differences to imitate certain ocean processes. But the problem again is taking measurements is difficult.
“So we came across this idea, which comes from the use of optics in astronomy. We use fluid in a rotating tank to imitate the rotation of the earth. When fluid rotates, its surface becomes parabolic. From above, this parabolic surface reflects light and works as a telescope. We can then use optical properties to measure what’s going on inside the water by the slight perturbations of the surface.”
By illuminating the fluid with multicolor light, Dr. Afanassiev is able to see and measure ocean jets, vortices and eddies – things that show up on satellite images but are often difficult to measure.
“The tank is basically a model of the hemisphere and using it we can model large scale things that happen in the ocean. Bands of colour represent movements and using them we can show what’s going on.
“What’s interesting about this is if you were going to run a computer model of the same experiment, you would need a super computer,” he said. “But here it’s easy to run an experiment in one hour and I can get approximately the same amount of data.
Dr. Afanassiev began working with this new method in 2006 when he was on sabbatical at the University of Washington. Upon his return to Memorial he created his own lab to continue that research, but still collaborates with his colleagues in Seattle – the only two known locations where this kind of research is being done. A new NSERC grant will soon allow him to purchase more advanced equipment to further his experiments.
As an artist in his personal life, Dr. Afanassiev said the visual nature of the data is particularly appealing to him.
“That is what attracts me,” he said. “You’re not just running computer models with numbers, you can actually see the data.”
People wishing to see more of his work can also find videos on YouTube.