New SERC “Teach the Earth” Activity on “Ocean Currents and Overflows”
One day in the office at the Geophysical Institute in Bergen last Friday, and for the first time in a long time I am writing a little bit of oceanography…
Category: tank experiment
24 days of #KitchenOceanography — now available as a book!
For all of you who know and love my “24 days of #KitchenOceanography” series (and for those who need to quickly look up what that was about and then fall…
A simple way to visualize how hydrostatic pressure increases with depth
I did this demo for my freediving club Active Divers (and if you aren’t following us on Insta yet, that’s what I am taking all these pretty pictures for!): 1.5l PET…
Denmark Strait overflow in a tank experiment
Since our Denmark Strait tank experiment from 2013 (see here in a post from 2014!) is still the one I refer to when I want to point to pictures of…
A #KitchenOceanography escape game for freedivers!
For the Christmas party of my freediving club, Active Divers, I made a freediving-themed #KitchenOceanography “escape game” (of sorts). If you are interested to use it for your own purposes,…
About #KitchenOceanography
At the end of last year, I did a poll on Twitter, asking what people would like to see more of in 2021: Kitchen oceanography, wave watching, teaching & scicomm…
Using #WaveWatching and #KitchenOceanography to prepare students for a one-day research cruise
When students have only one day at sea, it’s important to prepare them well for what will happen there so they get the chance to make the most of the…
My iEarth “Christmas Lecture” on #KitchenOceanography
I gave a talk withing iEarth’s seminar series to introduce myself to the network last week. And since it was the last lecture before the Christmas break, I tried to turn it…
Collaborative Taylor column experiments during lockdown
We’ve become quite experienced with remotely-controlled rotating tank experiments, but the current lockdown brought us into yet another new-to-us situation: We had plans to film and live-stream tank experiments from…
Tilting frontal surface under rotation / cylinder collapse
Torge and I are planning to run the “tilting of a frontal surface under rotation / cylinder collapse” experiment as “remote kitchen oceanography” in his class on Thursday, so I’ve…
Rotating vs non-rotating turbulence
Last Thursday, Torge & I invited his “atmosphere & ocean dynamics class” to a virtual excursion into my kitchen — to do some cool experiments. As you know, I have…
A common misconception in rotating tank experiments, and one way of maybe not reinforcing it
A very common misconception when looking at atmosphere & ocean dynamics in a rotating tank is that the center of the tank represents one of the poles and the edge…
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…
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…
Ekman layers in my kitchen
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…
Rossby-#WaveWatchingWednesday
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…
Brine rejection and overturning, but not the way you think! Guest post by Robert Dellinger
It’s #KitchenOceanography season! For example in Prof. Tessa M Hill‘s class at UC Davis. Last week, her student Robert Dellinger posted a video of an overturning circulation on Twitter that got me…
Reposting my “field report” for the DIYnamics blog
Reposting a guest post I wrote for the @DIYnamicsTeam‘s blog: When we came across the DIYnamics article right after its publication, Torge and I (Mirjam) were very excited about the…
Our Nature article in 20 tweets
(Not true, there were 22 tweets, but apparently I can’t count! :-D) For those of you that don’t follow my Twitter, here is what I posted over there the day…
Playing in a 13-m-diameter pool on a merry-go-round results in Nature article
A long, long time ago (ok, in fall of 2017) I got the chance to join Elin Darelius and Anna Wåhlin’s team for a measuring campaign at the Coriolis platform…
Giving it a side eye: Why we use high-walled tanks on our rotating table #FlumeFriday
Inspired by a recent twitter comment on how our tanks are higher-walled than those usually used on the DIYnamics rotating tables, today I’ll talk about why we went for those.…
Playing for #FlumeFriday
Yesterday, we’ve had four rotating tables operating simultaneously, for three different experiments. The one that everybody is gathering around in the picture above is our favourite experiment: a slowly rotating…
Rotating tank experiments on a cone
I had so much fun playing with rotating tank experiments on a cone this afternoon! And with Torge Martin (who I have the awesome #DryTheory2JuicyReality project with) and Rolf Käse…
Nansen’s dead water explained on YouTube
Remember the experiment on Nansen’s observation of “dead water” that Elin & myself set up as part of GEOF213? Our movies of this experiment are now featured in a brilliant…
Thermal forcing in a non-rotating vs rotating case: Totally different results
On Thursday, I wrote about the thermally driven overturning circulation experiment that Torge and I did as past of our “dry theory 2 juicy reality” experiments, and mentioned that it…
Salt fingers in my overturning experiment
You might have noticed them in yesterday’s thermally driven overturning video: salt fingers! In the image below you see them developing in the far left: Little red dye plumes moving…
Thermally driven overturning circulation
Today was the second day of tank experiments in Torge’s and my “dry theory 2 juicy reality” teaching innovation project. While that project is mainly about bringing rotating tanks into…
If one rotating table is awesome, four rotating tables are…?
I’m actually at a loss for words. Amazing? Spectacular? So much fun? All of that! Today was the first time Torge and I tried our four DIYnamics-inspired rotating tables in…
Taylor column
I was super keen on trying the Taylor column experiment, but maybe I expected things to look too much like my sketch below, or my technique isn’t quite perfect yet,…
Phase and group velocities in deep and shallow water
When Tor came to visit me in GFI’s basement lab a couple of days ago, he told me about an experiment he had seen in Gothenburg in the seventies. So…
Topographic Rossby waves in a tank
This experiment just doesn’t want to be filmed by me. Even though I spent more time on preparation of this experiment than on almost any other experiment I have ever…
Planetary Rossby waves — a side view
What I find really fascinating about the planetary Rossby wave experiment is to look from the side and see the columns develop and move around the tank. Here is a side-view…
Topographic Rossby wave
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…
Planetary Rossby waves
I ran my new favourite experiment again, the planetary Rossby waves. They work super well on the DIYnamics table we built in Kiel and they also worked really well the other…
Planetary Rossby waves filmed with co-rotating camera
And here is my new favourite experiment again: Planetary Rossby waves! This time filmed with a co-rotating camera. We have a square tank with a sloping bottom at solid body…
Topographic Rossby wave
Finally trying the topographic Rossby wave experiment I wrote about theoretically here! And it is working — ok-ish. If you know what you are looking for, you can kind of…
Planetary Rossby waves on Beta-plane. A super easy tank experiment!
This is seriously one of the easiest tank experiments I have ever run! And I have been completely overthinking it for the last couple of weeks. Quick reminder: This is…
Taylor column in a rotating tank
For both of my tank experiment projects, in Bergen and in Kiel, we want to develop a Taylor column demonstration. So here are my notes on the setup we are…
Rossby waves in a rotating tank — three different demonstrations
For both of my tank experiment projects, in Bergen and in Kiel, we want to develop a Rossby wave demonstration. So here are my notes on three setups we are…
Mariotte’s bottle: A nifty trick to control “reservoir height” in #dropphotography
In earlier posts on drop photography, you might have noticed that the reservoirs for the water that drops out and creates the beautiful liquid art has a weird cork on…
Spin down — lots of shear instabilities in our tank!
When you stop a rotating tank, lots of stuff happens and it is usually very impressive to watch. Sometimes we stop tanks on purpose to show for example the development…
Parabolic surface shape of a tank of water in solid body rotation
One of the first exercises Torge and I plan on doing with the students in our “dry theory to juicy reality” project is to bring a water-filled tank to solid body…
Rotating vs non-rotating turbulence — now with movie!
Lots of demonstrations being prepared for Torge’s and my “dry theory to juicy reality” project. Shown here today: rotating vs non-rotating turbulence. Because the only way to really appreciate how…
Spinning dye curtain — when a tank full of water has not reached solid body rotation yet
With all the rotating tank experiments I’ve been showing lately, one thing that comes up over and over again is the issue of solid body rotation. On our DIYnamics-inspired turntable for…
Baroclinic instabilities / Hadley cell circulation in a tank
The DIYnamics-inspired turntable that Torge and myself have been working on for our “dry theory to juicy reality” project is finally working well! This is what the setup now looks…
Combining rotation of a water tank with a temperature gradient: A Hadley cell circulation demo!
Yesterday, we combined a thermally-driven overturning circulation with the effects of rotation, and thus created a Hadley cell circulation. And while the tank was turning faster than we would have…
Combining a slowly rotating water tank with a temperature gradient: A thermal wind demonstration!
Setting up an overturning circulation in a tank is easy, and also interpreting the observations is fairly straightforward. Just by introducing cooling on one side of a rectangular tank a…
Why do we need a rotating tank to study ocean and atmosphere dynamics? A demonstration
For our project “Ocean currents in a tank: From dry theory to juicy reality“, Torge, Joke and I are working on building affordable rotating tanks to use in Torge’s Bachelor…
Tidal mixing on a (fjord’s) sill
A pink swirl going across a styrofoam block underneath a layer of yellow water? What’s going on here? The picture was taken in a water tank, simulating the circulation of…
Demonstrating Ekman layers in a rotating tank: High pressure and low pressure systems!
Ekman spirals — current profiles that rotate their direction over depth, caused by friction and Coriolis force — are really neat to observe in a rotating tank. I just found…
Vernissage of water sculpture photography by Wlodek Brühl, with explanations of the physics behind the pictures by yours truly!
I am a huuuge fan of Wlodek Brühl’s liquid art: Pictures of water sculptures that are created with focus on the tiniest of details, that only persist for milliseconds, but…
Tank demonstration of the circulation in a fjord
It has been a long time in the making, but finally we have a nice fjord circulation in our tank! Pierre and I tried to improve it 6 years ago,…
My first attempt at building a rotating table for kitchen oceanography using LEGO
Inspired by the article “Affordable Rotating Fluid Demonstrations for Geoscience Education: the DIYnamics Project” by the Hill et al. (2018), I spent a fun Sunday afternoon with my friends Joke and…
#KitchenOceanography with Judith and her hot chocolate
Let’s talk about zonal jets! They keep popping into my life all the time right now, and that has got to mean something, right? Zonal jets, for all that are…
Need your help! “Wish list” for a student lab for tank experiments?
I’d love your input: If your student lab for GFD tank experiments had to downsize, but you had to present a “wish list” for a smaller replacement, what would be…
Bottom Ekman layer without a rotating table
Can you do a bottom Ekman layer demonstration without a rotating table? That’s the kind of challenge I like :-) The way I’ve previously showed bottom Ekman layers is by…
Lee waves with an asymmetrical “mountain”
How will lee waves look differently if we are using the asymmetrical mountain instead of the symmetric one? And is symmetry actually important at all or are we just looking…
Instructions: Dead water demonstration in the GFI basement
This blog post is meant as guidelines if someone other than me might have to set up this demonstration at some point… Have fun! :-) Setting up the stratification If…
Instructions: Lee wave demonstration in the GFI basement
This blog post is meant as guideline if someone other than me might have to set up this demonstration at some point… Have fun! :-) Lee waves Lee waves are…
Demonstration: Nansen’s “dead water” in a tank!
A ship that is continuously pulled with a constant force suddenly slows down, stops, and then continues sailing as if nothing ever happened? What’s going on there? We will investigate…
Accidental double-diffusive mixing
When setting up the stratification for the Nansen “dead water” demo (that we’ll show later today, and until then I am not allowed to share any videos, sorry!), I went…
Observing waves in a tank
So you thought filling water into a tank was boring? Not on my watch! This is how we fill up the tank: Through a hole at the bottom. Which leads…
Please discuss: Experimental setup for Nansen’s “dead water”
During my last visit to Bergen in August, we set up a nice “dead water” experiment. However, there are nice experiments, and then there are awesome experiments, and since Elin…
Experiment: Double-diffusive mixing (salt fingering)
On the coolest process in oceanography. My favorite oceanographic process, as all of my students and many of my acquaintances know, is double-diffusive mixing. Look at how awesome it is:…
Experiment: Temperature-driven circulation
My favorite experiment. Quick and easy and very impressive way to illustrate the influence of temperature on water densities. This experiment is great if you want to talk about temperature…
Waves in a density stratification. One of the most beautiful tank experiments I’ve ever seen.
It’s pretty impressive when a mountain moves through a stratification and generates lee waves. But what I find even more impressive: The waves that travel behind the mountain when the…
Tank experiment: Lee waves in a fancy density (and dye) stratification
Did you seriously think we’d stop tank experiments with only 2-layer systems? Nooo! Today, the plan was to set up a continuous stratification, which I have been planning to do…
The one where it would help to understand the theory better (but still: awesome tank experiment!)
The main reason why we went to all the trouble of setting up a quasi-continuous stratification to pull our mountain through instead of sticking to the 2 layer system we…
Dead water — the fancy experiment including Nansen himself
Now that we do have a really awesome 12-layer 6-color stratification, we obviously had to do the dead water experiment again. This time we chose to include a not-too-happy-looking Nansen…
“Dead water” or: ship-generated internal waves
And here is another experiment that can be done with the same stratification as the lee waves: Towing a ship to explore the phenomenon of “dead water”! Dead water is…
Lee waves in the tank
Did you guess what we needed the stratification for? Yes — we are moving mountains again! :-) What we want to look at: How a current reacts to an obstacle…
Kelvin-Helmholtz instabilities
I’m back at my happy place — the teaching lab at GFI in Bergen! :-) Here a quick look at what we’ve been doing today: Filling the large wave tank!…
Experiment: Oceanic overturning circulation (the slightly more complicated version)
The experiment presented on this page is called the “slightly more complicated version” because it builds on the experiment “oceanic overturning circulation (the easiest version)” here. Background One of the…
Experiment: Oceanic overturning circulation (the easiest version)
“The easiest” in the title of this page is to show the contrast to a “slightly more complicated” version here. Background One of the first concepts people hear about in the context…
Experiment: Eddy in a jar
Rotating experiments in your kitchen. Eddies, those large, rotating structures in the ocean, are pretty hard to imagine. Of course, you can see them on many different scales, so you…
Experiment: Influence of stratification on mixing
A wind stress is applied to the surface of a stratified and a non-stratified tank to cause mixing. This is a pretty impressive experiment to run if you have a…
Experiment: Ice cubes melting in fresh water and salt water
Explore how melting of ice cubes floating in water is influenced by the salinity of the water. Important oceanographic concepts like density and density driven currents are visualized and can…
A sketch of a learning sequence on fjord circulation experiments
I’ve been wanting to develop a good fjord circulation experiment for a long time now — I wasn’t happy with the one we used back when I was teaching in…
Observing the “melting ice cubes” experiment with a thermal imaging camera
Remember the melting ice cube experiment? Great! If I had the chance to teach an intro to oceanography or some other class where I have time with students over a…
Investigating ocean currents in a rotating swimming pool
Reposting from Sci/Why “where Canadian children’s writers discuss science, words, and the eternal question – why?” — Have you ever wondered what happens when you put a 13-m-diameter swimming pool on…
Of a pool that sits on a merry-go-round and how we use it to investigate ocean circulation in Antarctica
You know I like tank experiments, but what I am lucky enough to witness right now is NOTHING compared to even my wildest dreams. Remember all the rotating experiments we…
My workshop at MeerKlima.de
Today I ran a workshop at the MeerKlima.de congress in Hamburg: A congress for high school students, organised by a student committee. The large lecture theatre of the chemistry department at…
Workshop prep and a riddle
Looking at the picture below, can you guess which experiment I am going to do at the MeerKlima.de workshop? Yep, my favourite experiment — melting ice cubes! :-) And I am…
Pythagoras’ Cup
Yep, I’ve been playing this weekend :-) After seeing this on Facebook a while back I just couldn’t resist… Enjoy! :-)
“Coriolis fountain”
We’ve been thinking about Coriolis deflection a lot recently (see links at the end of this post). But this weekend, at Phaenomenta Flensburg, I came across a so-called “Coriolis fountain”.…
Considered exemplary: My “ice cubes melting in fresh water and salt water” in the “on the cutting edge” teaching collection! :-)
After reading recently that I am being considered the queen of the melting ice cube (aaaaw, thank you!!!), having my movies of the experiment featured in Elin Darelius and Petra Langebroek’s article…
Standing waves in a tank
And really high order ones, too! On Monday, I showed you a movie on wave generation in Hamburg Ship Model Basin (HSVA)’s wave tank. At the end of that movie, we…
Eddies in a jar
Rotating experiments in your kitchen. Do you know those Saturday mornings when you wake up and just know that you have to do oceanography experiments? I had one of those…
Influence of stratification on mixing
A wind stress is applied to the surface of a stratified and a non-stratified tank to cause mixing. This is an experiment that Martin and I ran at the JuniorAkademie this…
Tilting of a frontal surface under rotation
Eddy in a rotating tank. This is an experiment that Pierre and I ran two years ago in Bergen but that – as I just realized – has not been…
Capillary effects
When hydrostatics just doesn’t explain things. Occasionally one notices water levels in straws that are slightly above the water levels in the glass. And of course – even though we…
Marsigli’s experiment
Density-driven flow. The experiment presented in this post was first proposed by Marsigli in 1681. It illustrates how, despite the absence of a difference in the surface height of two fluids,…
Hydraulic jump II
More movies of my kitchen sink. I am really fascinated by the hydraulic jumps in my kitchen sink. I can’t believe I haven’t used this before when I was teaching!…
An overturning experiment (part 3)
By popular demand: A step-by-step description of the overturning experiment discussed here and here. I wrote this description a while ago and can’t be bothered to transfer it into the…
An overturning experiment (part 2)
How to adapt the same experiment to different levels of prior knowledge. In this post, I presented an experiment that I have run in a primary school, with high-school pupils,…
An overturning experiment
A simple experiment that shows how the large-scale thermally-driven ocean circulation works. Someone recently asked me whether I had ideas for experiments for her course in ocean sciences for non-majors.…
Modeling the Denmark Strait Overflow
Ha, this is a bad pun. We are modeling the Denmark Strait Overflow – but in a non-numerical, small-scale-and-playdough kind of way. More than a year ago, Kjetil and I ran…
Salt fingering – DIY
How to easily set up the stratification for the salt fingering process. Setting up stratifications in tanks is a pain. Of course there are sophisticated methods, but when you want…
Diffusive layering. Or: This is not a trick question!
The “other” double-diffusive mixing process. After having talked extensively about double diffusive mixing in my courses, I tend to assume that students not only remember that there is such thing as…
Salt fingering
How to show my favorite oceanographic process in class, and why. As I mentioned in this post, I have used double-diffusive mixing extensively in my teaching. For several reasons: Firstly,…
Double-diffusive mixing
On the coolest process in oceanography. My favorite oceanographic process, as all of my students and many of my acquaintances know, is double-diffusive mixing. Look at how awesome it is:…
Water not in solid body rotation yet
Confusing students even more by discussing how momentum is being transferred from the tank to the water. As you remember, we are preparing for the Ekman experiment and need to…
Water in solid body rotation.
Spinning up a tank until all water particles move with the same angular velocity. Before running the Ekman spiral experiment, the tank needs to be spun up to solid body…
Ekman spiral in a tank.
Tank experiment showing (the effects of) the Ekman spiral. One experiments that has been run in GEOF130 forever is the “Ekman spiral” experiment. A tank filled with water is spun…
Ship-generated internal waves
A tank experiment showing ship-generated internal waves. When entering a fjord from the open ocean by ship, it can sometimes be noted that the speed of the ship changes even…
Water seeks its level.
A solution for the siphon problem of the fjord circulation experiment. After having run the fjord circulation experiments for several years in a row with several groups of students each…
Filling the tank
A movie of patterns observed in the flow when filling the tank for this experiment. Even though there are tons of scientific things to discuss with this movie, like the…
Details of lee waves in the tank.
A movie focusing on details of the lee waves in the tank. In this post, we investigated lee waves in a tank in a general way. Here, I want to…
Surface imprints of internal waves
How internal waves in the ocean can be spotted on the surface. Under certain conditions, internal waves in the ocean can be spotted at the ocean’s surface due to changes…
Internal (lee) waves in a tank.
Lee wave experiment in a large tank with a moving mountain. In this previous post, we talked about internal waves in a very simple experiment. But Geophysical Institute has a great…