We discovered a new galaxy! Or at least a very pretty vortex
When we move our wall back and forth, we create very strong wing tip vortices that persist for quite a long time. Above, you see the vortex, lit by a…
Tag: LEGI Grenoble
“No one believes a theory, except the theorist. Everyone believes an experiment — except the experimenter.”
Different types of experiments, and why we use such a weirdly-shaped “Antarctica” and are happy with it. When we want to show people images of our model experiments in a tank, people often imagine…
How to make sure the properties of water in a tank experiment are *just right*
For all our experiments here on the rotating platform in Grenoble, we have had a source, introducing an artificial current into our water-filled tank. With flow rates between 15 l/min…
Closing off our channel at the ice-shelf end to avoid unrealistic outflow
We are very deep into discussing all the different ice shelf experiments that have happened so far. As you see above, the white board in our office is filled with…
And now on to even more realistic ice shelves!
We have already described experiments where our ice shelf was tilted, making the setup a little more realistic* than before (link here). But then later that day, we did two…
What a day in the Coriolis lab looks like
You have seen plenty of images of our experiments over the last weeks (and if you have not, scroll back on the blog!). Time to show you what a day in…
What happens when a current meets an obstacle? Topographic steering
As long as water depth and latitude stay the same, a current usually happily goes straight forward. However, a large part of what we are doing at the Coriolis tank in…
Tilting the ice shelf! Or: Our experiments are getting more realistic
Until now, we have used an “ice shelf” (a plastic box) which had a horizontal bottom (Read more about the general setup of the experiment in Nadine’s post). The bottom of…
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…
Looking at our current’s structure over depth
For our scientific analyses, we look at the flow field at several discrete levels throughout the water depth. But we can — just for fun! — look at them almost…
What happens when you accidentally change the rotation rate of the tank just a liiiittle bit? Inertial oscillations!
At some point the angular velocity of our tank was accidentally changed a tiny little bit. That was almost instantly corrected, however we could see the effect for quite some…
Elin receives award for polar sciences!
I’m sure there will be an official press release some time later today, and we will link to it when it comes out, but I thought I should let you all…
Don’t you just love eddies? Happy Monday!
I could watch flow fields for the rest of my life and not get bored :-)
See the Coriolis deflection when filling the tank!
I just realized we never showed you that you can see the Coriolis deflection on the inflowing water when we started filling the tank! So here you go. Isn’t that cool?…
Always beautiful: Kelvin-Helmholtz instabilities!
Don’t you just love watching this kind of stuff? :-)
Fairy dust sprinkler, or: more neutrally buoyant particles!
What happens when the almost neutrally buoyant particles that we use to visualize the flow field have sunken out of the surface layer? The fairy-dust sprinkler comes and sprinkles more fairy dust!…
How we can see vertical slices of the flow field in our tank
We’ve talked before how we use the laser to light up neutrally-buoyant particles on horizontal slices of our tank, but we can actually also do this in the vertical. This is…
We are constantly adding water to the tank — how is the water level kept stable?
You’ve probably been wondering about this, too: We have a constant inflow from our “source” into the tank. How do we keep the water level stable? Worry no more —…
This is what experiments look like at our rotating tank
Just so you don’t get bored over the weekend (and because they are so so beautiful to look at!) here are a couple more sneak peek gifs of our experiments.…
About the influence of viscosity: The Reynolds number
This blog post was written for Elin Darelius & team’s blog (link). Check it out if you aren’t already following it! — I read a blog post by Clemens Spensberger…
Who is faster, the currents or the waves? The Froude number
A very convenient way to describe a flow system is by looking at its Froude number. The Froude number gives the ratio between the speed a fluid is moving at,…
The ocean is very deep. It’s also very shallow. On the L/H aspect ratio and the size of the tank.
When we come back from research cruises, one of the things that surprises people back home is how much time it takes to take measurements. And that’s for two reasons: Because…
Why we actually need a large tank — similarity requirements of a hydrodynamic model
When talking about oceanographic tank experiments that are designed to show features of the real ocean, many people hope for tiny model oceans in a tank, analogous to the landscapes…
Of swirls, eddies and fairy dust
Similarly to last Friday’s Kelvin-Helmholtz instabilities, observing swirls and eddies made from green fairy dust is not really what we are in Grenoble for. But are they pretty! And it is actually…
Why are we rotating a huge tent with our tank?
When watching the images or movies that show the rotating tank from the outside, you may have been wondering about why the whole structure — tank, office above the tank,…
Totally not the focus of our experiments, but so beautiful! Kelvin-Helmholtz instabilities
This is really not the focus of our experiments here in Grenoble, but they are too nice not to show: Kelvin-Helmholtz instabilities! They showed up really nicely in our first…
About neutrally buoyant particles, popcorn, and more bubbles
When you see all our pretty images of currents and swirling eddies and everything, what you actually see are the neutrally buoyant particles that get lit by the laser in…
Exploring the source of Antarctic currents…
Sometimes a polar oceanographer needs to be in Antarctica to observe things first hand and up close :-)
No, the edge of our tank is not “the equator”
A very common idea of what goes on in our tank is that we have a tiny Antarctica in the center and that the edge of our tank then represents the…
First full week of experiments ended successfully! :-)
As you see, we have increased the rotation rate of the tank! From 1 rotation in 50 seconds to now 1 rotation in 30 seconds. Which means that at the…
How the strength of the current influences which path it takes. First observations!
Depending on how strong a current we introduce in the 13-m-diameter rotating tank to simulate the strength of the coastal current in Elin et al.’s 2016 article (link on our…
How our experiments relate to the real Antarctica
After seeing so many nice pictures of our topography and the glowing bright green current field around it in the tank, let’s go back to the basics today and talk…
Water jet pumps, and why we don’t like them in our experiments
Just a quick update from the lab tonight: We are fixing more bugs by the hour :-) First: the bubble-free source. I have previously written about how we thought we…
What are we actually trying to measure in our rotating swimming pool?
You’ve heard us talk a lot about rotating swimming pools. Nadine has written about why we care about Antarctic ice shelf melting (link), why the ice shelf is melting (link)…
Getting rid of bubbles in our jet
Sometimes the devil is in the details… On our first day at the Coriolis platform in Grenoble, I took a picture of the “source” in our experiments (see above): The plastic…
We have water in our rotating tank! Now testing the lasers
Above you see the very first water coming into our tank. Only a couple of hours, and the tank was full! And in solid body rotation (since it has been spinning all the…
Why do we go to all the hassle of rotating our swimming pool?
This blog post was written for Elin Darelius & team’s blog (link) which you should totally follow if you aren’t already! — We have started rotating and filling water into…
Calibrations and decisions
This blog post was written for Elin Darelius & team’s blog (link). Go check out that blog, more cool stuff being added there every day! :-) — Remember this little…
Rotating a whole swimming pool
This blog post was written for Elin Darelius & team’s blog (link) and is just reposted here to keep my archives complete. If you aren’t already following Elin’s blog, you…