Tag: temperature

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 super excited (not only because as of now, April 15th, it has 70 retweets and 309 likes. That’s orders of magnitude more successful than any […]

First of all, let me say how much I love having chats like the one Elin and I had over the weekend (which you only see the very beginning of above). I had gotten into a bit of a rut kitchen oceanography-wise, which, I am happy to report, is over now! Thanks, Elin! :-) One […]

I saw the idea for this experiment on Instagram (Max is presenting it for @glaeserneslabor) and had to try it, too! The idea is to put drops of dye into hot and cold water and observe how in hot water the dye is mixed a lot faster than in cold water — after all, molecules […]

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 the theoretical teaching of ocean and atmosphere dynamics, today we started with the non-rotating case of a thermally driven overturning circulation. Very easy setup: A […]

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 this in a tank! And in order to see what is going on, we have dyed some of the water pink. Can you spot what […]

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 into a meeting after filling in layer 4 (the then lowest). When I came back, I wanted to fill in layer 5 as the new […]

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 influencing density. Although it doesn’t actually show anything different from a temperature driven overturning experiment, where circulation is determined by hot water rising and cold […]

If you don’t know my favourite experiment for practically all purposes yet (Introduction to experimenting? Check! Thermohaline circulation? Check! Lab safety? Check! Scientific process? Check! And the list goes on and on…), check it out here. (Seriously, of you don’t recognize the experiment from the picture below, you need to read up on it, it’s […]

Using the “melting ice cube” experiment to let future instructors experience inquiry-based learning. I recently (well, last year, but you know…) got the chance to fill in for a colleague and teach part of a workshop that prepares teaching staff for using inquiry-based learning in their own teaching. My part was to bring in an experiment […]

One of the most exciting things about work travel? Staying in tons of different hotels, which all have different opportunities to play with water. For example at a recent team event, there was this tap with a really efficient aerator, that made the hydraulic jump look even more exciting than usual: And then at a […]

Some time ago, I wrote two blog posts on the importance of playing in outreach activities for the EGU’s blog’s “educational corner” GeoEd. Both have now been published, check them out! Here is the link on EGU’s website (here) and in case that ever stops working, it is also available on my own website (here […]

I am updating many of my old posts on experiments and combining multiple posts on the same topic to come up with a state-of-the-art post, so you can always find the best materials on here. And today I would like to present you my favorite experiment: Salt fingering! Check out the new page I made for […]

In my last post, I showed you the legendary overturning experiment. And guess what occurred to me? That there is an even easier way to show the same thing. No gel pads! (BUT! And that is a BIG BUT! Melting of ice cubes in lukewarm water is NOT the process that drives the “real” overturning! For […]

For one of my side-projects I needed higher-resolution photos of the overturning experiment, so I had to redo it. Figured I’d share them with you, too. You know the experiment: gel pads for sports injuries, one hot (here on the left), one cold (here on the right). Blue dye on the cold pad to mark the […]

Because surely there is one more post in this topic? ;-) For those of you who haven’t heard about the “melting ice cube” obsession of mine, please check out the links to other posts at the end of this post. For everybody else’s sake, let’s dive right in! When Kristin and I ran the workshop […]

I had to do the complete series of experiments, of course… The other day I mentioned that I had used salt from my kitchen for the “ice cubes melting in fresh and salt water” experiment, and that that salt was the super healthy one that was both iodized and containing folic acid. And what happened […]

Somehow I am stuck on this demonstration! I can’t let go of this experiment. Last time I posted about it, someone (Hallo Papa!) complained about the background and how I should set a timer and a ruler next to the beakers for scale. The background and timer I did something about, but the ruler I […]

Kristin’s and my workshop at EMSEA14. As I mentioned before, Kristin Richter and I are running the workshop “Conducting oceanographic experiments in a conventional classroom anywhere” at the European Marine Science Educator’s Association Meeting in Gothenburg, Sweden. There is quite an active Twitter crowd around, so you can follow the storyfied meeting or look out for […]

Weird things happening when ice cubes melt. Remember I said that there were weird and wonderful things going on when I last ran the melting ice cubes in salt and fresh water experiment? It is really difficult to see in the picture below (sorry!) but you can probably spot the ice cube floating at the […]

Or why you should pay attention to the kind of salt you use for your experiments. The melting ice cubes in salt and fresh water is one of my favorites that I haven’t written about in a long time, even though (or possibly: because) I wrote a whole series about it last year (see links at […]

My absolute favorite experiment ever: salt fingering. I know I’ve said it before about another experiment, even today, but this is my absolute favorite experiment and I still get endlessly fascinated. I’ve written about salt fingering before, and given tips on run the experiment, but today we tried a different setup. We used the same […]

One of my all-time favorite experiments. The salt group got a bit bored from watching ice cubes melt, so I suggested they look at temperature differences for a change, and they ran the “leaking bottles” experiment. Watch a movie combining their four different setups below!

Removing a barrier between waters of different densities and watching what happens. (deutscher Text unten) Today, one of the groups performed a classical experiment (shown for example here) – but the awesome thing is that they came up with the planning pretty much by themselves in order to determine the effects of temperature and salinity […]

Don’t you just love lava lamps? I got a lot of weird looks when I excitedly told people about two years ago that I had just bought a lava lamp. But what’s not to love about them? Plus they are great for teaching. These days kids don’t know them any more, so they are missing […]

More physics applications  connected to tea. After the frustrations of taking pictures of steam in my last post, I decided that I could use the very same cute mug to show other stuff, too. I know it has been done over and over again, but we have new students every year, don’t we, so someone […]

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 that experiment with a group of high-school students and when writing a post about a much more sophisticated version of this experiment I realized I […]

Is there an equation of state for hypersaline water at very cold temperatures? A friend of mine is looking to calculate changes in density of a hypersaline Antarctic lake from summer to winter. Apparently, this lake is about 10 times saltier than the ocean and often cools down to -17C at the bottom. My own spontaneous […]

Why heat and salt diffuse at different rates. Why do heat and salt diffuse at different rates? This seems to always be puzzling students when talking about double diffusion. Well, why should they diffuse at the same rate? The processes of molecular diffusion of heat and salt are very different. In the case of heat, […]

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 to just quickly set something up in class (or in your own kitchen) you don’t necessarily want to go through the whole hassle of a […]

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 double-diffusive mixing, but that they also remember our discussions on how the process works, and that they would be able to transfer this to processes […]

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, I think that the process is just really cool (watch the movie in this post and tell me that it isn’t!!!) and that the experiments […]

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: Double-diffusive mixing happens because heat and salt’s molecular diffusion are very different: Heat diffuses about a factor 100 faster than salt. This can lead to […]

Students acting out the process of sound being refracted towards the region of minimum speed. We’ve been talking about refraction lately. Waves get bent in the direction of lower velocity. This holds for light and sound and even ocean waves. However, students find it conceptually difficult to understand why waves are being bent towards lower […]

Students build thermometers. As described in this post, I like to have students build “instruments” to measure the most oceanographic properties (temperature, salinity and density). I find that they appreciate oceanographic data much more once they have first-hand experience with how difficult it is to design instruments and make sense of the readings. Over the last […]

Movie on how the most important instrument in oceanography works. On our cruise on the WHOI research vessel Knorr in 2011, Sindre Skrede (find him on twitter or vimeo for many more exciting pictures and movies!) and I made a movie for his blog, describing the most important oceanographic instrument. We recently translated the movie from Norwegian to […]

The “ice cubes melting in fresh water and salt water” experiment the way I usually use it in class. — Edit — For an updated description of this experiment please go to this page! — Edit — You might remember the “ice cubes melting in fresh water and salt water experiment” from a couple of […]

Experiment to visualize the effects of density differences on ocean circulation. This is the first post in a series on one of my favorite in-class experiments; I have so much to say about it that we’ll have to break it up into several posts. Post 1 (this post) will present one setup of the experiment, […]

My favorite experiment. Quick and easy and very impressive way to illustrate the influence of temperature on water densities. Today in the “introduction to oceanography” (GEOF130) we conducted my favorite experiment ever: Cold water in one of the small bottles is dyed blue, hot water in the other small bottle is dyed red. Both are […]

Three in-class experiments run in parallel. Great if you want to discuss how properties are measured and what kind of difficulties you might encounter. Temperature, salinity and density are the most important properties in physical oceanography. Measuring them with a CTD is easy. But can you, using basic household items, build instruments to measure those properties? My […]