Tag Archives: density

Thermal forcing vs rotation tank experiments in more detail than you ever wanted to know

This is the long version of the two full “low latitude, laminar, tropical Hadley circulation” and “baroclinic instability, eddying, extra-tropical circulation” experiments. A much shorter version (that also includes the end cases “no rotation” and “no thermal forcing”) can be found here.

Several of my friends were planning on teaching with DIYnamics rotating tables right now. Unfortunately, that’s currently impossible. Fortunately, though, I have one at home and enjoy playing with it enough that I’m

  1. Playing with it
  2. Making videos of me playing with it
  3. Putting the videos on the internet
  4. Going to do video calls with my friends’ classes, so that the students can at least “remote control” the hands-on experiments they were supposed to be doing themselves.

Here is me introducing the setup:

Today, I want to share a video I filmed on thermal forcing vs rotation. To be clear: This is not a polished, stand-alone teaching video. It’s me rambling while playing. It’s supposed to give students an initial idea of an experiment we’ll be doing together during a video call, and that they’ll be discussing in much more depth in class. It’s also meant to prepare them for more “polished” videos, which are sometimes so polished that it’s hard to actually see what’s going on. If everything looks too perfect it almost looks unreal, know what I mean? Anyway, this is as authentic as it gets, me playing in my kitchen. Welcome! :-)

In the video, I am showing the two full experiments: For small rotations we get a low latitude, laminar, tropical Hadley circulation case. Spinning faster, we get a baroclinic instability, eddying, extra-tropical case. And as you’ll see, I didn’t know which circulation I was going to get beforehand, because I didn’t do the maths before running it. I like surprises, and luckily it worked out well!

Thermal forcing vs rotation

The first experiment we ever ran with our DIYnamics rotating tank was using a cold beer bottle in the center of a rotating tank full or lukewarm water. This experiment is really interesting because, depending on the rotation of the tank, it will display different regimes. For small rotations we get a low latitude, laminar, tropical Hadley circulation case. Spinning faster, we get a baroclinic instability, eddying, extra-tropical case. Both are really interesting, and in the movie below I am showing four experimentsm ranging from “thermal forcing, no rotation”, over two experiments which include both thermal forcing and rotation at different rates to show both the “Hadley cell” and “baroclinic instability” case, to “no thermal forcing, just rotation”. Enjoy!

24 Days of #KitchenOceanography — Melting ice cubes that are forced to the bottom of a beaker

Welcome to 24 days of #KitchenOceanography! Both English and German instructions below.

Herzlich Willkommen zu 24 Tagen Küchen-Ozeanographie! Deutsche und Englische Anleitungen weiter unten.

24 Days of #KitchenOceanography — Double-diffusive mixing

Welcome to 24 days of #KitchenOceanography! Both English and German instructions below.

Herzlich Willkommen zu 24 Tagen Küchen-Ozeanographie! Deutsche und Englische Anleitungen weiter unten.

24 Days of #KitchenOceanography — Mediterranean Outflow

Welcome to 24 days of #KitchenOceanography! Both English and German instructions below.

Herzlich Willkommen zu 24 Tagen Küchen-Ozeanographie! Deutsche und Englische Anleitungen weiter unten.

24 Days of #KitchenOceanography — Surface waves and internal waves

Welcome to 24 days of #KitchenOceanography! Both English and German instructions below.

Herzlich Willkommen zu 24 Tagen Küchen-Ozeanographie! Deutsche und Englische Anleitungen weiter unten.

…Oooops. Changed the picture, didn’t change the text. Left & right is the wrong way round… Thanks for catching this, Uta!

…Oooops. Das Bild geändert aber nicht den Text: Links und rechts leider falsch rum. Danke fürs Bescheid sagen, Uta! :-)

24 Days of #KitchenOceanography — Overflow experiment

Welcome to 24 days of #KitchenOceanography! Both English and German instructions below.

Herzlich Willkommen zu 24 Tagen Küchen-Ozeanographie! Deutsche und Englische Anleitungen weiter unten.

24 Days of #KitchenOceanography — Melting ice cubes!

Welcome to 24 days of #KitchenOceanography! Both English and German instructions below.

Herzlich Willkommen zu 24 Tagen Küchen-Ozeanographie! Deutsche und Englische Anleitungen weiter unten.

This is an experiment I’ve written extensively about on this blog before. Check out all the posts tagged melting ice cubes experiment if you are interested in much more in-depth discussions!

Über dieses Experiment habe ich bereits sehr viel und sehr viel in die Tiefe gehend geschrieben. Alle Posts dazu findet man unter dem Tag “melting ice cubes experiment“.

24 Days of #KitchenOceanography — Density-driven currents

Welcome to 24 days of #KitchenOceanography! Both English and German instructions below.

Herzlich Willkommen zu 24 Tagen Küchen-Ozeanographie! Deutsche und Englische Anleitungen weiter unten.

24 Days of #KitchenOceanography — Oceanic overturning circulation

Welcome to 24 days of #KitchenOceanography! Both English and German instructions below.

Herzlich Willkommen zu 24 Tagen Küchen-Ozeanographie! Deutsche und Englische Anleitungen weiter unten.