Newswise — UNIVERSITY PARK, Pa. — The National Science Foundation (NSF) has awarded Matthew Rau, assistant professor of mechanical engineering at Penn State, $410,000 to better understand how particulate matter behaves in the ocean.

Through this work, Rau hopes to contribute to the current knowledge surrounding carbon dioxide absorption and sequestration in the ocean and the potential impact it could have on climate change.

The three-year project will focus on understanding disaggregation, or how organic matter like phytoplankton clumps together and breaks apart through the ocean’s movements, and how that phenomenon affects the transport of carbon through the water column. It is known that when carbon is captured from the atmosphere, it is taken up by small organisms in surface waters. Some of this organic matter naturally settles deeper into the ocean, which helps mediate and limit the effects of climate change by sequestering that carbon to the deep ocean. It is not yet known how much of or how fast these mostly organic particles actually make it to the deep. With enhanced knowledge of how the carbon moves through the ocean and eventually sinks, researchers expect that climate change predictions will become more accurate.

Rau has proposed a two-phase research plan. The first phase will focus on theoretical modeling and experimental testing within a laboratory. Due to the ongoing pandemic, Rau and his team will primarily focus on model development and designing the laboratory experiments until they are able to safely return to campus.

At that time, using simulated organic marine particulates made from phytoplankton, the researchers will conduct fluid flow experiments and measure how different forces impact the size and movement of the material.

Rau said, “This is a useful first step because in the lab, we can gather very precise measurements using high-speed cameras and optical instruments. But the lab would never be able to simulate the natural environment.”

Phase two is where his oceanic field experience comes into play. Rau began this journey in the summer of 2019, when he spent 10 days conducting particulate research during an ocean cruise with the University-National Oceanographic Laboratory System (UNOLS). Through that experience, he is now prepared to conduct his own one-week research expedition in the Gulf of Maine.

“We will be going out on a ship to do adapted versions of our lab experiments, but off the back of a boat,” Rau said. “We are going to compare the data, see if what we’re studying in the lab is applicable to the natural environment and see if our hypotheses are holding up.”

While oceanographic work is not a field most would expect a mechanical engineer to contribute to, Rau hopes his expertise in multiphase flows can provide a unique perspective.

“Environmental scientists are very interested in understanding how the ocean interacts with the atmosphere,” he said. “As a mechanical engineer, it is both an interest and a passion of mine to understand the physics of what’s happening.”

Adrian Burd, a professor of marine sciences at the University of Georgia, is a collaborator on the project.