Introduction

I study physical limnology, physical oceanography, and geophysical fluid dynamics, which describe the dynamics of momentum and heat in large lakes and oceans. Most of my research focuses on small-scale processes that occur over short timescales, such as internal waves and their associated turbulence. This research improves predictions of currents and turbulent diffusion. Currents transport people lost at sea, nutrients, larvae, sediment, and pollution. They also impact sonar and offshore maritime operations. Turbulent diffusion is critical for accurately predicting the distribution of heat in the ocean. I work to answer scientific questions through a combination of observations, theory, and numerical modeling.

Fieldwork on large lakes and in the ocean is challenging because we often sample remote locations and place instruments in harsh conditions. However, the effort is worthwhile, because large lakes and oceans are greatly under-sampled, and new measurements almost always lead to new insights and some unexpected results. The University of Minnesota Duluth is an excellent place to conduct fieldwork on the Great Lakes because it is home to the R/V Blue Heron, the only UNOLS vessel on the Great Lakes.

The Navier-Stokes equations, which describe the basic theory of fluid dynamics, have been around since the 1840s, but physicists and mathematicians are still working to understand their complex dynamics. In fact, there is a standing $1,000,000 prize for finding a general solution to the equations. My theoretical work focuses on finding idealized, as opposed to general, solutions to the Navier-Stokes equations, which only include the most important (and least complicated) physics that are necessary to accurately predict and explain observed dynamics.

Lastly, numerical models bridge the gap between observations and theory. I employ both complex community models, such as the MIT general circulation model, and simpler "home-made" models to explain observations and pick apart the underlying dynamics of a system.