Next attempt at the topographic Rossby wave! This time with following the geosci.uchicago.edu instructions more closely…

…and then the tank had hickups, so we did get waves, but a lot more diffusive than we had hoped, because the tank slowed down a lot more and in a more bumpy fashion than I had planned…

Setup of the topographic Rossby wave experiment

For a demonstration of topographic Rossby waves, we want the Coriolis parameter f to stay constant but have the depth H change. We use the instructions by geosci.uchicago.edu as inspiration for our experiment and

• build a shallow ridge into the tank, from a cylinder in the middle to the outer wall. My solution: Take a 1.5 cm (outer) diameter hose, tape it to the bottom of a tank to achieve a ridge with smooth edges
• 7 cm water depth
• spin up the tank to approximately 26 rpm
• wait for it to reach solid body rotation (ca 10 min)
• introduce dye all around the cylinder in the middle
• reduce rotation slightly, to approximately 23 rpm so the water inside the tank moves relative to the tank itself, and thus has to cross the ridge which is fixed to the tank
• watch it change from laminar flow to eddies downstream of the ridge. Hopefully ;-)