Hi Jan,

Wow, thanks for all the inspiring questions!

If we just simulated the influence of Coriolis force on the ocean, we’d end up with basically a bucket of water in solid body rotation. In order to generate the eddies, we need to introduce some kind of disturbance to the system. Either with ice, or for example by stirring. What we can see (not very obviously, but rather by carefully positioning ourselves such that we see reflections of e.g. lights on the surface of the tank) is that the surface is being deformed by eddies. I think the potassium permanganate would probably obstruct what we are trying to see, because it would be sinking by itself due to its different density, thus making it seem like there is downwelling due to eddies going on when it’s just sinking due to higher density. I have yet to come across tracers that would act as really passive tracers and would really show vertical movement of water without influencing it themselves.

I’ve tried mixing with wind (e.g. here: https://mirjamglessmer.com/2018/08/01/experiment-influence-of-stratification-on-mixing/) but I haven’t gotten very far. In the ocean, we have space enough for a fetch that goes over many many kilometers, I haven’t come up with a good way to simulate that in a tank and always end up creating new problems when I manage to fix one. What kind of setup were you thinking of?

Best wishes, Mirjam

I wonder what happens if only the Coriolis force on the surface of our spinning planet is simulated in the tank. Would the downwelling of anticyclonic eddies be visible in your tank? I mean without the density difference of the ice? For example, a piece of sponge with potassium permanganate?

But what i really would be interested in would be highly stratified layers and wind forcing and which kind of turbulence’s created by different kinds of wind – constant wind blowing horizontal – from a above – high frequency winds with impulses etc. – to see which kind of winds create turbulence’s that cross the thermocline and would mix heat to greater depths… Further, i really would like to see how mixed layer depth influences turbulence’s or eddies and vertical mixing of a stratified or weakly/non stratified water column and water transport across the thermocline.

All the best

Jan

p.s. and sorry for the sloppy writing, just trying to understand turbulence’s and vertical mixing in the oceans – tough subject thou, to come to grasph’s with ;)