Teaching

The theory behind geophysical fluid dynamics (GFD) and numerical models of the ocean and atmosphere is complex. The hydrodynamic equations, a set of mathematical equations including the Navier-Stokes equations for momentum, alow us to decribe changes in motion, temperature, salinity/humidity and density of a water or an air parcel. The complexity of these equations can be challenging and still often involves approximations to derive a subset with an analytical solution describing a single phenomenon. All this is not easily linked to the vast body of water we call ocean -- or the sky above.

My motivation is to create "hands on" access to these equations, to provide my students with the experience of connecting with the theory by both physically and virtually running experiments themselves in a wet lab and on a computer. Experiments that show phenomena that are described by the simplified equations on the black board.

The behavior of fluids is absolutely stunning and part of our world in so many ways. Popular science centers around the world present fascinating hands on examples of GFD. I just wanted this for my classes, for myself to play with.

In their book Marshall & Plumb nicely present GFD theory along with experiments based on their Weather-in-a-tank rotating table. This is fantastic but seemed not within reach at the time.

For me, an article by the DIYnmaics project (Hill et al., 2018, BAMS) tipped the scale. They presented a really simple, affordable and fun setup for a rotating tank. Intrigued by the simplicity (and the cool Lego motors), I started making this an educational project.

Together with a good friend and great expert in "kitchen oceanography", Mirjam Glessmer, I designed a practical GFD course based on acquiring 4 of the DIYnamics setups so that every student would get to experiment with a rotating fluid. Our idea was funded by the PerLe project at Kiel University. See here (English) and here (German) for first field reports.

"Playful learning" is typically not associated with university courses. So, let's call it experimenting. Either way, the key is to experience yourself first, the beauty of fluids in motion and second, the beauty in understanding the link to the theoretical considerations on the board. Bringing water into motion, marking currents with tracers (food coloring), observing dispersion, mixing and its changing characteristics under rotation (Taylor column) is simply exciting and fun. On top, The experimenting and sharing always creates a much more relaxed atmosphere in the seminar room than just working with chalk and board.

Since my research is based on computer models it was only natural for me to include small projects using Python in my GFD courses. This is from data analysis (e.g. thermal wind balance across the Gulf Stream) to small animations (trajectories, stream lines, streak lines). The ultimate goal is to enable the students to actually simulate the rotating tank experiments on their computers—but that's still on the to do list.

The rotating tank classes, the PerLe project and its continuation as kitchen oceanography in the virtual class room during the pandemic got some attention and was highlighted in some university news outlets as well as the local newspaper.

Our experience using hands-on experiments in a GFD class we shared at the Ocean Sciences Meeting in 2020.

We also started a blog about teachign ocean science at Kiel University and GEOMAR in general.