Taeho Lim was sitting in a fluid dynamics class at the University of Minnesota Duluth (UMD) when he found his calling: studying internal ocean waves.

That led Lim, a recipient of the Mylan Radulovich Physics Fellowship, to UMD’s Blue Heron research vessel, where he spent nearly four weeks last summer gathering data on internal waves in Lake Superior. 

Internal waves occur beneath the surface where different densities of water meet (think oil and vinegar). “About 30 percent of tidal energy goes into internal tides—internal waves that occur during daily tides,” says Lim, who earned his master’s degree in physics this spring. “Yet we don’t know a lot about them.”

Internal waves in the ocean are hidden. Therefore, they’re difficult to detect and study. Taking part in the Lake Superior study with his advisor, assistant professor Sam Kelly, Lim measured turbulence and currents, giving him insight into the way ocean waves operate. 

Lim and Kelly are using mathematical and numerical simulations to better understand these waves and the effect they may have on the ocean’s circulation and climate. “Predicting future climate depends not only on atmosphere but also on understanding the ocean,” Lim says. “They’re one thing together.”