PAOC Spotlights

MIT-WHOI graduate student Jörn Callies' research on atmospheric and oceanic wave fluctuations garnered him an award at the recent American Geophysical Union Conference—the largest worldwide conference of its kind. Read more about it here.

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Jörn Callies, a graduate student in the MIT-WHOI Joint Program in Physical Oceanography, is a recipient of the American Geophysical Union’s (AGU) 2014 Outstanding Student Paper Award for his research on atmospheric and oceanic wave fluctuations. A panel of judges at the AGU Annual Conference selects only a few winners each year.

“Jörn’s work represents an important contribution to our understanding of the oceans and atmosphere,” said Raffaele Ferrari, the Director of MIT EAPS Program in Atmospheres, Oceans, and Climate, and Callies’ advisor. “The AGU judges agreed and awarded him one of only four student awards in all oceanography disciplines.”

For years, atmospheric scientists have known that wind fluctuations are stronger at scales smaller than 500 km. Using observational data from aircraft and shipping tracks, Callies and his colleagues developed a method for distinguishing between different classes of motion, such as vortices and internal waves, to determine the cause of these strong fluctuations. “This method allows us to interpret observations from the atmosphere and the ocean that we’ve had for a long time in a new way,” said Callies.

In the atmosphere, he found that fluctuations on small scales are largely due to internal waves—oscillations at the interfaces between air of different densities, similar to how ocean surface waves are created at the interface between air and water. Callies also found that internal waves dominate current fluctuations around geostrophic eddies in the ocean.

From these results, we now know that airplanes fly on internal waves. More important, however, the results suggest weather may be more predictable than previously thought. “Internal waves have regular and predictable motions, unlike the turbulent irregular cyclones and fronts that we experience on larger scales,” explained Ferrari. Callies continues to research what drives these motions and will compare those drivers to ocean observations using this method. The work is published in Proceedings of the the National Academy of Sciences and the Journal of Fluid Mechanics.