Category Archives: Uncategorized

Treibholz Podcast, my first episode in 2020

Check out today’s episode of Treibholz Podcast, where Maxie, Ronja and I talk about the oceanic overturning circulation and #KitchenOceanography (in german), while each of us is doing a similar experiment in her own home. Is podcasting a good format to convey what’s going on with our water, ice and dye? We’ll know soon! :D

[photo] Picture of Mirjam smiling in the camera to show how happy it would make me if this showed up on Twitter

Exciting life update! Joining GFI as adj assoc prof! :-)

It’s been in the making for a while, but I am super excited to announce that I will be joining the Geophysical Institute at the University of Bergen as an adjunct associate professor!

Here is a video I filmed to introduce myself at the institute’s meeting today that I sadly couldn’t attend.

I am very excited to be working more closely with many super awesome colleagues — Elin, Kjersti, Tor to just name a few — and to have an excuse to be in Bergen more often!

If you want to celebrate with me, there are several options:

Option 1: Do some #KitchenOceanograpy!

From next Tuesday onwards, there will be a new kitchen oceanography experiment each and every day for 24 days (also in German and in Norwegian)! Follow along, take pictures, post them on social media, tag me and let’s talk about some exciting ocean physics!

Option 2: Go #WaveWatching and send me a #FriendlyWaves!

You know the drill: Enjoy some wave watching, take a pic, post it on social media, tag me, and let’s talk about what physics are behind the waves you saw! And about how awesome oceanography and water are ;-)

A workshop on building and maintaining a mentoring network in academia

Last week I gave a workshop on “taking ownership of your own mentoring” at Kiel University again (link to the pptx slides in case you want to give a similar workshop yourself). This is one of my favourite topics to talk about (especially in combination with how to use social media for that purpose; and I love getting the participants’ feedback that they realized during the workshop that they already have a much larger network than they were aware of, and that they are excited to work with it more purposefully in the future) and since I redid my slides for the purpose, here is the workshop in a nutshell.

What I always find super important to point out:

  1. Good mentoring is not a magical unicorn. It is possible (and not terribly difficult) to find it! But make sure that you don’t overtax one person with all your mentoring demands, it makes much more sense to build a network of many different peoples so there are built-in redundancies ;-)
  2. Mentoring has many different facets. It helps to be aware of what they are in general as well as what aspects are most relevant to you right now. But also considering the aspects that aren’t relevant right now but still building a network for to help in those areas is probably a good idea.
  3. Mentoring can be found almost anywhere and at any time. In my workshop, you learn where & how to do it!
  4. SUPER IMPORTANT: Mentoring is not a one-way street. Of course you cannot always mentor everybody back the same way they mentor you, and in many cases it’s probably not even appropriate to try. BUT: That’s where the network idea comes in. Pay it forward, or help someone else out. You can be as much of a mentor to many people as others are to you. And you should be aware of that and try to fill the mentor-role, too!

And this is “The Mentoring Map” that we suggest: For all the different aspects of mentoring, you should try and put at least three-ish names of people or organizations (for details on the individual mentoring facets, check out the chapter we published on it)

And here are a couple of ideas where you can find people for all those different facets:

As if meeting people wasn’t difficult enough, now, in covid-19 times, it has become even more difficult. So that’s why the next three sessions of the workshop will look at how mentoring can be found via social media. Looking forward to working more with that group of young scientists, some of which have already connected with me on social media. See, it is working! :-)

P.S.: If you are intersted in this workshop, please feel free to contact me. It works great virtually :-) Here is a link to the pptx slides in case you want to give a similar workshop yourself. Please feel free to use, share, modify! Any questions, suggestions, comments, please let me know!

Visualizing boundary layers using rheoscopic fluid

Or: How does momentum get transferred from a rotating tank to the water?

I recently noticed — and it was confirmed by observations and student feedback that my friend Kjersti got — that it is not at all obvious to students how momentum gets transferred from a rotating tank into the water. For me, the explanation “friction” always seemed sufficient. But Kjersti asked her students about it, and for them friction was something that can only slow down things, not speed them up. So I’ve been trying to find a good way to show how the water is actually spinning up and down: From the sides towards the center, and from the bottom up.

I am using a rheoscopic fluid here (prepared after Borrero-Echeverry, 2018, plus blue food coloring). Rheoscopic fluid is “current showing”, as in it looks homogeneous as long as there is no current shear, but as soon as there is shear, these silvery structures show up, thus showing all the small turbulent motion going on in the tank. (The rheoscopic fluid is not transparent, so you can only see the surface and cannot look into the tank)

Here is a movie, where I am first switching on the rotation and spinning up the water, (then bumping against the rotating table, sorry!), then switching the rotation off again and spinning the water down.

Can you see how when the tank starts spinning, shear instabilities at the side wall of the tank form? This turbulent boundary layer grows over time. I didn’t let the tank spin up to solid body rotation but switched it back off maybe half way there. When the tank stops rotating, a similar thing happens: A turbulent boundary layer forms and slows down the water from the outside in (and bottom up).

So basically this:


Borrero-Echeverry, D., Crowley, C. J., & Riddick, T. P. (2018). Rheoscopic fluids in a post-Kalliroscope world. Physics of Fluids, 30(8), 087103.