Photo comics for scicomm from the central Greenland ice sheet? Yes, please!

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Do you remember how I started experimenting with an app that made sketches from photos to see if reading waves might be easier from sketches than from photos? (Btw, approximately half of the answers on whether or not sketches are easier to read than pictures were along the lines of “YES!!!! DEFINITELY!!!” and the other half were like “NOOO — DON’T DO THAT TO YOUR PICTURES!!!”)

That only happened because I saw something really cool that Petra Langebroek was testing in preparation for the outreach she was planning on doing from her expedition to central Greenland, and since I thought it was so cool, I had to download an app that could do the same, and then I fell into that hole of playing with the app…

Anyway. What Petra is doing is fascinating: From her expedition to central Greenland, she reports back using the Lego figurine “EastGRIPninja” and his scientist friends to tell the story of how science is done on top of the ice sheet. For that, she takes pictures of EastGRIPninja and his friends in real locations and lets them explore, and tell stories.

For example, EastGRIPninja gets a tour of the camp:

And that’s pretty cool — it’s not too often that I get a look into one of the domes! I don’t know what I expected to see inside, but definitely not this much plywood. And probably fewer flags, too. And (spoiler alert!) would you have guessed that they have a tabletop football game in there, too?

Also super interesting: How does going to the toilet work in the middle of the Greenland ice sheet? That’s something EastGRIPninja needs to find out fairly early on, too, and again, it’s something to do with flags. So if you are curious, you should go and check it out!

Petra says that the weather is bad right now and that she doesn’t know when they’ll be able to start drilling (and thus posting interesting science content). But there are so many questions that I have that can easily be answered in bad weather, for example:

  • does EastGRIPninja get to play tablefootball and cards etc with the scientists?
  • why drill exactly where you are and not somewhere else?
  • what’s for dinner and is it something people would voluntarily eat at home when they get back?
  • who has to cook / do the dishes?
  • how many scientists are there at any one time?
  • do you work/sleep on watches like you would at sea?
  • what’s the temperature in the dome like? Cosy?

And what are your questions that EastGRIPninja could answer?

Click on the image below to read the whole story (which is being updated pretty much daily, so remember to check back to see whether your questions have been answered and what else is going on!). EastGRIPninja, Petra and their team are still there until mid July and I can’t wait to learn more about their adventures!

#DayOfTheSeafarer — #WakeWatching on Kiel fjord

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I’ve been on my fair share of ships over the years, but even though I enjoy my month or two at sea every year, I cannot even begin to express the respect I have for seafarers who spend all their working life at sea. Being away from home for at least half the year, living in a small, confined space with people they did not get to choose themselves, not even having the autonomy to choose what meals to cook while at sea, all while doing hard physical work.

The seafarers I know personally do this out of their free will — their love of the ocean compensates for the sacrifices they make to be at sea. But let’s not forget that there are also many people who don’t have the luxury to choose what job they work in.

Anyway, seafarers’ work influences us all: It provides us with wave watching opportunities: The ferry you saw in the picture above left the wake you now see below.

Jokes aside: Shipping gives us access to goods that we otherwise wouldn’t have access to. It provides us with jobs, with food, with transportation. With knowledge about the world and the ocean — without the amazing work the crews on research ships do, there wouldn’t be any oceanography!

Our lives would be very different without the work that seafarers do every day, the sacrifices they make and the risks they take. On the Day of the Seafarer, maybe stop and think for a minute about what your life would look like if it wasn’t for all these men and women, doing the work they do. I, for one, am full of respect for what they are doing! And I’ll be sure to let the seafarers that I personally know know about this today! Thank you to all the crews on the research ships that I’ve sailed on, you guys and girls are amazing!

A pilot ship making waves, and what happens to the waves over time

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This is the story of a pilot ship, merrily sailing along on a beautiful day, making waves.

Since it’s windy and Kiel fjord is a little choppy, the waves break and both side of the V-shaped wake with the pilot ship at its tip are visible. See the foam of the breaking waves? And in the middle of both sides of the V, visible as a lighter-colored stripe, there is the turbulent wake where the ship’s propeller has set the water into chaotic motion.

Both constituents of the wake — the V-shaped feathery waves and the turbulent wake — stay visible for quite some time after the ship has passed!

Can you spot the one side of the V approaching the shore?

A little while later, the pilot ship returns. nice bow wave (where its bow is breaking the water apart) and all. Also note the wave field inshore of the floating wave breaker — it is a lot calmer than on the outside!

But not for long. The pilot ship is making waves!

The V-shaped wave keeps spreading, one of its sides coming closer and closer to the wave breaker.

Wow, now it’s there! Can you imagine what it will do to the floating wave breaker, and what that in turn will do to the wave field inshore?

Below, you see that the V-shaped wake is now so wide that one end is reaching the edge of the wave breaker, which is already moving almost violently in the waves.

And the moving wave breaker now produces waves of its own, radiating away from the wave breaker, towards the shore.

See how those waves propagate further and further towards the shore and form a crisscross pattern with the waves that come in through the gap between wave breakers?

That was a nice wave watching break! :-)

Wave watching on Schwentine river

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Surprise! I did some wave watching yesterday!

Ok, let’s start with something simple to warm you up: A duck’s wake.

And wind waves (coming in from the top right) hitting a patch of moss on the side of this little pier, and then radiating away as half circles.

Here is a movie of that because it’t pretty cool, actually.

Are you ready for the cool stuff? A water strider making waves in the movie below! It hops happily on the water, and every time it lands, capillary waves radiate outward from its point of impact.

And in the movie below, there is another water popping up after a couple of seconds. But what I find fascinating about the movie below: In the beginning, there are these smooth waves running through that were created by a breeze further upwind on the lake. But over the course of the movie, the texture of the surface changes: It gets rougher and ripples appear as the breeze moves in where I am filming. So within half a minute the lake looks substantially different!

And below a movie clip that should be used in physics classes because it illustrates so nicely that waves transport energy, not matter. How do we see that?

Can you spot the long waves going through right to left, and the small ripples that seem to, if anything, move from left to right? (Not true, that’s an optical illusion! They are moving right to left, too, only so much slower than the longer ones)

But if water was moving with the longer waves, the small waves would have to be transported with it, just riding on the other wave field. Clearly that is not the case! And that’s because only energy and the shape of the waves is transported, not the actual water the waves consist of.

And below is the picture that I would use to open my hypothetical wave photography exhibition with. Or maybe have it printed in a size to fill a whole wall if I ever had to furnish a large house.

Wave watching on Brodowinsee

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What do you do the night before the most important three days of your whole work year? Yep — some wave watching with friends!

On Thursday night, we went to cool down and relax after preparing for GEO-Tag der Natur all day long. Don’t these images make you feel much more calm instantly?

And look at the waves in the atmosphere that only become visible because, as air is moved up and down by the waves, conditions change such that clouds form in the troughs but disappear at the peaks of the waves. Contemplating these things is so relaxing to me! Especially when looking at them both in the sky and in their reflection on the water.

And if you look carefully at the picture above, you see tiny little wave rings in the lower right corner. That’s small fish touching the lake’s surface from below, creating disturbances that propagate away from where the surface was deformed.

Other things make similar pattern, albeit on a larger scale. My colleagues K and K, for example, are creating wave rings, too. Theirs are much larger and propagate all the way across the lake!

And thanks to K&K’s waves, the reflections of the atmospheric waves on the water becomes even more interesting as they are deformed by surface waves on the lake.

Is there any better way to calm down any worries you might have?

And, btw, the GEO-Tag der Natur turned out a blast. I’ll update you on that once I’ve had A LOT OF SLEEP! Until then — go and do some wave watching! :-)

My kids’ article on the formation of sea ice is out!

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I recently published an article about how sea ice forms which, I think, turned out pretty well. But the coolest thing is the illustration that Jessie Miller did to go along with the article:

Illustration by Jessie Miller for my article published in Frontiers Young Minds, used with permission

Seeing this illustration (and, of course, having the article published) was a super nice surprise during the busy run-up to my big event, which is actually happening right now (good thing I know how to schedule blog posts ;-)). The illustration makes me suuuuper happy because to me it really captures what the article is about and, more importantly, what my goal in writing the article was. And I feel seen and understood in a profound way, and reminded of who I am. Never underestimate the power of #scicart! Thank you, Jessie!

Reference:

Glessmer, M. S. (2019) How Does Ice Form in the Sea? Front. Young Minds 7:79. doi: 10.3389/frym.2019.00079

Wave watching in Kleinwaabs — and my first real Insta story!

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So today (and tomorrow and the day after) is the big event that I have been working towards all year in my not-so-new-anymore job: The GEO-Tag der Natur! If you are curious about what’s going on there, check out our Instagram account @geo.tag.der.natur that Kati is doing an amazing job with!

As you can imagine, the weeks running up to this weekend were quite busy and a little stressful, too. So last Sunday I went to the beach to hang out with friends and do some wave watching! Because nothing has a more calming effect on me than watching water…

For example below we see nicely the effect of the wave (and wind) breakers on the wave field. In the lee of the wave breaker, the water is completely calm, whereas towards the right of the bay waves form and grow larger and larger.

And below we see a pretty cool “diffraction at slit” example: Straight wave fronts reach the slit between two wave breakers, and as they propagate through the slit, they become half circles.

But to relax and get my thoughts away from my job, I tried something new: I created and posted my first ever Instagram story! I’m not quite sure it’s my format, but I definitely had fun! What do you think? Would you like to see more of those? (I only just realized the story is in german and my blog in English. Posting anyway… Would anyone like to see this kind of stuff in English? Then please let me know and I’ll see what I can do…)

https://vimeo.com/341862851

(P.S.: Since I made this for Instagram, the format of the video was optimized for viewing on a mobile phone. Therefore it looks crap embedded in a blog. But some you win, some you loose…)

What do you do to relax and get your mind off of work? Wave watching and posting about it on social media? Have you ever tried that? Or what else would you recommend?

Watching a V-shaped wave widen over time

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Yesterday we looked at a very cool wake that Nena sent in as a #friendlywaves, today I have a nice gif for you to illustrate one of the points that I was trying to make.

We are looking out of a porthole at a ship sailing past. And the further the ship sails, the wider its V-shaped wake becomes at a fixed position.

Picture by Arnt Petter Både, used with permission

Nena sent me some #friendlywaves from Lago Maggiore

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This is a #friendlywaves challenge, where I try to explain other people’s wave photos and they tell me how I did.

I love it when my friends see waves, think of me, whip out their cameras, take pictures, and send them to me! In this case, Nena even used a telephoto lens and took the amazing pictures below that she allowed me to share with you!

They are the perfect example for talking about wakes when a ship doesn’t just go straight ahead. Because, of cause, ships going straight ahead are the easiest case, like the one we see below.

Picture by Nena Weiler, used with permission

Here, we see the two different constituents of a wake: The turbulent wake that is the white stripe right behind the boat, that turns blue a little way behind the boat but stays a lighter color than the surrounding water.

And then there is the V-shaped wake with the boat at its tip. This V-shaped wake consists of very many individual waves that are fairly short in the direction parallel to their crests, and that are shifted slightly so the further away from the boat you look, the wider the V opens. I usually call this the “feathery” wake, since it consists of all these little “feathers”, but since I need the “feather” image for something else today, I’ll just call it the V-shaped wake here.

Now when the boat takes a turn, this messes up the structures of the waves making up the V-shaped wake (or makes them more interesting, depending on your point of view). Below, the boat has taken a right turn, which you can see from the turbulent wake that starts right behind the boat as a white stripe that then changes color to a lighter blue than the surrounding water (with a darker stripe to each side, and then the V further out).

Picture by Nena Weiler, used with permission

Now looking at the individual waves of the V-shaped wake, we see that they get bunched up on the right side of the boat’s trajectory, while they are getting fanned out on the left side.

Now imagine the boat’s trajectory as the shaft of a feather. If you have ever bent a feather, you will have observed that on the side the shaft is bent towards, the individual barbs (I looked this up: barbs are the little thingies that spread outwards from the feather’s shaft) get bunched together, while on the other side they fan open.

So far, so good. Still with me?

Now what happens as time goes on is that the V opens up — the two sides move away from each other. We don’t usually notice this because we are used to focussing on the wake relative to the ship rather than to some fixed vantage point. But if we looked at a fixed point while a ship going past, we’ll see the wake spreading over time until one side of the V reaches us.

Picture by Nena Weiler, used with permission

And this spreading of the V is what’s making interpretation of the picture below a little difficult. The picture below is showing almost the same part of the ocean as the one above (see the little white and blue moored boats in the bottom right corner of the lower picture? They are the same boats that are visible at the left of the bottom right corner above), only a little later. During the time between the two pictures, the ship moved further towards the bottom left corner, but also the wake spread further apart.

Above, you see that some “barbs” start running into each other (the ones where the bend is strongest, where there is foam on breaking waves because the waves suddenly become a lot steeper due to interference). So some time later, they have grown longer and are now crossing each other, which leads to the checkerboard pattern located right inside the bend of the boat’s trajectory. If you follow the V-shaped wake from the boat backwards, you can still make it out, even though it’s been deformed by the ship turning around.

Picture by Nena Weiler, used with permission

Tell me, Nena, is your family happy with this explanation? :-)

Algae as tracers for currents in Parsteiner See

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Remember how I described a breeze creating a wave field on Parchsteiner See?

Well, it did not only cause a wave field, it also set up a circulation! Which I might not have noticed, had nit not also started deforming the algae patches! At first, it looked like above, and we could walk into the lake without having to wade into the green, like so.

But then a little later, there were algae everywhere, and you could see the swirls in the current traced out in green! Pretty cool passive current tracer, aren’t they?