I didn’t write a #WaveWatchingWednesday post last week. I think when my last blogpost ended with the Oslo ferry leaving Kiel for the last time in the forseeable future, it really hit me how far away so many of the people I love are, indefinitely out of reach. I had a couple really tough days isolated all by my self, with additional high fevers and a very active imagination, but not eligible to be tested. Anyway, things got better, I started being able to go out of my flat again, in the very early mornings to meet as few people as possible. I started taking pictures again and posting them to my Instagram. Initially, they were mainly pictures of sunrises (over water, of course ;-)) and I still didn’t feel like talking about waves. Anyway, today was the first day I felt the urge to talk about waves again, so here comes a bunch of pictures and then a real #wavewatching pic in the end!
From here on, things got better.
The way I felt about being in isolation changed drastically when I brought wave watching into my livingroom. Now I am actually quite content on my sofa, looking at the porthole and the view… Nice change when compared to the days before when I really felt isolated and not happy. Was it just being creative today that turned things around for me? I don’t know, but I’m happy with the result in any case
And then: My first snow this winter! :-)
And I built a snowman! :-)
Not a lot of water in Kiel fjord today, but: poolnoodle waves! When the water is very shallow compared to the wavelength, waves deform into this weird shape with very long troughs and these bulging crests that look as if poolnoodles were being pushed towards the shore.
Here is last week’s summary of my #WaveWatching Instagram @fascinocean_kiel. Social distancing in Kiel isn’t so bad… At least until I started to take it seriously enough to stay inside full time, so this week we only have pictures until last Saturday. And there will probably be no wave watching in the near future. But I’m thinking about going through the archives and explaining some stuff better now that I have time. Does this sound interesting?
Anyway, let’s start.
So much going on in one picture! Can you explain all the different waves? Let me try below…
Red lines show the incoming waves; the wake of a ship that passed a minute ago and whose feathery wake is now reaching the sea wall.
As the feathery wake meets the sea wall (on whivh I am standing), it gets reflected. The reflected wave crests are marked in green.
With all these waves, the pontoon is bobbing up and down, making those waves that trace its contours & propagate away from it (blue).
And finally, the yellow waves radiate from the edge of a pontoon that you can’t see, which is also moving with the waves.
How super awesome is wave watching, please???
I love the contrast between the bright sky in the east that we are looking at, and the darkness behind me. That, plus simple geometric shapes like this pier, make for amazing wave watching because different sides of the waves are reflecting either the bright or the dark parts, and then the deformation of the geometric shapes in their reflection gives us a good idea of the shapes of the waves. Plus I just love being out for the sunrise ☀️
You think a little ice on the beach is going to keep me from a quick dip into the sea? Ha, think again! ♀️
Social distancing is not so bad when it means sitting in a beautiful sunny spot, looking at water.
But watching the Oslo ferry leave for the last time in at least the next couple of weeks is somehow really emotional for me. It’s not only the source of one of my favourite wave watching events (actually, several: Beautiful wakes, and the 180 degree turn in a really narrow part of the fjord befor backing up into its berth), it’s also what connects me to all my friends in Norway. And my mini escape when I need some time at sea without having time or opportunity for “serious” (i.e. research) cruises. God tur, hope to see you back in Kiel soon!
Sun glint can be so helpful to make waves visible more clearly, like this morning. I love the combination of the turbulent wake, the feathery usually V-shaped (and in this case quite wonky) wake, the sun. Always fun to watch!
Just moments later and the feathery wonky V is a lot more difficult to recognize (its remnants are reaching the shore at the very bottom of the picture). But the turbulent wake looks a lot more interesting now with that cloud-like appearance!
And one last look at the billows of the turbulent wake. I mean it’s quite impressive for such a large ship to do a 180 turn in such a narrow fjord. But it’s also really cool to see it like this, documented in the wave field!
Oh, and then I did some #FriendlyWaves for Christina on a super cool picture taken from a plane off Panama. Check it out!
My standard #KitchenOceanography overturning circulation experiment (recognize the tank & the cool pad?) put into a very different light by @davidcarrenohansenfor the upcoming issue of @sciencenotes5x15! Can’t wait to see how the pictures turn out — definitely not the “snap a pic with my phone in my kitchen” I always do!
#FlumeFriday with pretty much the opposite approach to my usual kitchen oceanography: Yesterday I got to visit @lufi_luh and see all their super cool flumes and wave tanks. Unfortunately without water, but you bet that I’ll be back! Can you imagine the endless possibilities?
Some things make me happy every time. Like watching hydraulic jumps in a sink. What’s your guess why in the second picture the radius of the shooting water circle is smaller even though the flow out of the tap is the same in both pics?
Interesting: distinct ripples on the sandy seafloor, but not all the way up to where the plants start. Why not? It’s not a change in water depth. I think it must be because of some plant wave interaction that dampens the waves enough that they can’t move the sand any more. Or possibly some reflection from the sea wall that messes something up? What do you think?
#SciCommSunday: Did you notice how I am always writing how much _I_ am fascinated by wave watching or kitchen oceanography or that stuff? Head over to my blog post on a recently published study in which it was found that writing in first-preson style is actually helpful in #SciComm because it makes you be perceived as more authentic and helps build a connection with your audience!⠀
Picture taken on my last trip to Bergen (when P & I met up to go watch the tidal current you see in the background).
Then one day on my way to work: Shear flow (see the essies?) between two watermasses. The muddy brown water coming out of Alsterfleet, the other one is “normal” brackish Elbe water in the Port of Hamburg. I saw this from the train station and had to go investigate & document! :)
Another week, another #WaveWatchingWednesday! Here are my collected Instagram posts from my wave watching Insta @fascinocean_kiel.
Even quick glimpses of water make me happy: #WaveWatching from the train! And even from the train, we see gusts of wind as darker, rougher patches of the water.
This is what a storm flood looks like at low tide. #fail. Somehow my work schedule and the tidal cycle didn’t match well today…
I always love mornings at the water side!
Clearly the sheltered side of the fjord today with long waves coming in from somewhere else, but hardly anything happening locally here. But higher surface roughness on the other side as can be seen from a darkening towards the horizon!
But: nice waves in the atmosphere today! Cloud stripes are often due to air oscillating up and down and clouds forming and disappearing as atmospheric conditions change with height. Check out all three pics to see those cloud stripes from different angles!
Today: slightly more water than normal, hence the swimming pool where the rigid part of the pier is flooded between the two pontons.
Can you spot the turbulent wake of where the ferry just sailed out of the picture to the right? It’s the very bright stripe across the water. On the left side of the picture you see a line of darker “feathers” of the V-shaped feathery wake (you know, the V with the ship at its tip, the 2D Mach cone…).
Also very nicely visible today: Lots of reflected waves everywhere, especially parallel to the straight edges of those harbour basins. Weird mixture of no wind (thus smooth water surface) yet enough waves to cause these reflections. But also maybe just the right water level so waves hit a ledge that is always just slightly submerged and then falls dry, thus causing those waves. Who knows? I’m just guessing, didn’t bother looking at it closely enough to find out…
Saturday stroll. These cliffs change a lot over time — se how the old footpath is gone?
Watching gusts of wind play on the water
Tide lines on the beach
Waves getting bent towards the shore
Good morning on this windy Sunday! Fascinating to watch how even over relatively short distances of open water there is such a transfer of energy to make waves this size!
Sneak peak at powertools making eddies! That’s going to be some awesome #KitchenOceanography for @sciencenotes5x15 when it’s done! Picture will then be by @davidcarrenohansen and will look quite differently! I’m just documenting the “making of” here because who would not be curious about that? :D
Best thing for my mental health: Running along the waterfront. Bonus if it includes wave watching as it does today: See how in the reflections of the lights there are zones where the water is almost mirror-like (those are the sad zones: no waves) and then there are dark zones with hardly any lights reflected (where the breeze roughs up the surface) and then there are those in-between zones, where you can see individual waves. Lovely evening!
How is it that I am sooo happy to be home and at the same time this view makes me long to be back at sea?
Meetings at GEOMAR are always a welcome opportunity for me to take the slightly longer way along Kiel fjord for some wave watching. Today see how waves close to the boat house have a completely different direction than those closer to the shore?
That’s because the ones closer to the shore are the reflection of the other wave field.
This might not be so surprising to people who don’t look at Kiel fjord as much as I am, but what is the Sweden ferry doing there? Why is it turning on its way into port rather than out? The seagull seems as confused as I am… :-D
But: enough reason for more wave watching (not that I ever need more reasons to wave watch than just wanting to do it…). This corner between the sea wall and the solid structure of the pier is always great for reflections and interferences! Can you spot the two wave fields, the original and reflected one?
Well hello, thanks for making these beautiful waves for me, little buddy!
A wake approaching the pier! How do I know? Because there isn’t any wind here (which I could feel, but which you can also see because there are no ripples on the water) and the wavelengths are too short (and the waves too far in the fjord) for the waves to have traveled here from a distant storm somewhere in the Baltic.
Also, if you quickly turn your head (or look down to the next pic), you can juuust catch the Sweden ferry disappearing around the corner into the mouth of the fjord — she’s the one who made the wake (and it only arrived at the shore when she was already this much further along!).
This is an interesting wave field: Inside the inner harbour, therefore relatively sheltered from the wind and big waves. Yet windy enough to create all these ripples on the waves that made it into the harbour! (And don’t you just love the sun? Yep, yesterday’s picture…)
Lovely day for a swim in the sun! And with such bright light, reflections on the surface are so strong that you can’t look into the water from this angle (which you could on the picture I posted a couple of days ago on an overcast day!)
Here the waves making it into the sheltered, inner harbour are reflected on the straight edge of the sea wall and make this beautiful, very regular wave field. See the ring waves radiating from that pole? The thing in the lower left corner is some reflection on my phone’s lens, it’s not on the water…
Love the tiny ripples on the waves, and the contrast between the “sea state” outside and inside the harbour basin!
And this is what it looks like when you look from the edge of the harbour basin downwind. From the right, waves are travelling around the edge of the wall, but new wave ripples only start forming quite some distance downwind of the wall!
For comparison: Looking into a similar direction from a pier that rests on poles and lets the waves run through underneath almost undisturbed…
But then Tuesday: Windy day again! Can you spot the different wave fields? I see three:
1️⃣The long waves with crests more or less parallel to the shore that come out of Kiel fjord
2️⃣The short waves with crests perpendicular to the shore that come from the direction of Kiel locks and sneak around the corner
3️⃣The wind wave field that is generated right here: smooth surface right off the shore that then becomes rougher and rougher the longer the fetch gets
Unfortunately I missed the white caps (or, to be honest, I preferred to watch from the inside & didn’t take pictures when the weather was really interesting, hail and all…
Opening my mom’s fridge, I went „WHAT IS THAT SUPER AWESOME LAYERED SAUCE???“. Turns out this was accidental #KitchenOceanography. The sauce was blended when it went into the fridge, then separated and formed layers. Density stratification!
Unfortunately I have to report that the internal wave experiment (that obviously had to happen!) didn’t go so well, too much damping. Layers just veeery slowly return back to horizontal…
The flood is coming in quickly! Most waves reach further in than the one before did, thus reshaping the look of the beach. Footsteps of dozens of people enjoying their stroll — first just blurred a little, then soon gone completely. Covered in foam, shells, then water. Until, a couple of hours later, the water recedes again, each wave leaving fresh, smooth sand for someone to be the first to have walked on that part of the beach, until the whole beach is covered in footprints again. Am I the only one who finds this strangely poetic?
My sister pointed out the waves from the fountain on the left meeting the wind waves coming in from the right, and that ended up being almost as exciting as a bunch of lambs born only the night before!
Not wave watching, but how cute are these little lambs???
What is going on in the picture below? Just from looking at the picture I could only guess, but luckily I took dozens of pictures of that location with slightly different angles and at different times, so I could figure it out!
To the right of this picture, there is a groyne. Some of the higher waves, like the one whose crest is perpendicular to the beach (looking like it’s wiping out all the smaller waves) make it over that groyne. Most don’t, so they get bent around the groyne and approach the beach with crests more or less parallel to the beach, like we would generally expect waves to behave. And there you have it: a really weird-looking wave field!
It’s so fascinating to observe water interact with obstacles, not only because of what waves are created (although that’s definitely awesome!) but also because of what water does to things that try to stop it.
Take for example groynes, those structures that are built into the sea perpendicularly to the beach. Their purpose is to regulate beach erosion by breaking up the current along the shore and creating pockets of calmer water where sand falls out and accumulates on the beach rather than being taken downstream with a current. There are many different kinds of groynes for different purposes. Those that always stick out of the water or those that are submerged, those that are completely closed off and those that let a little water and sediment through. And I find it so interesting to look at structures and ponder why specific design choices were made.
In this picture, the groyne is old and either eroded or was designed for a coastal shape that has changed since: high waves manage to flow around the landward end of the groyne, eroding the beach there. Looks cool, but not so cool for coastal protection…
But it makes it even more interesting to come back to that beach soon to see how things develop: very close by old groynes were being pulled out of the sand as we walked past, so there will very likely new coastal protection measures in place next time I visit! What do you think what they will look like?
Next, I went to the trade fair “BOOT” in Düsseldorf for a long weekend. Super exciting! Here are my posts from that huuuuge trade fair on water sports:
Then: hotel breakfast #WaveWatching.
Here is how you do it: take a latte glass (the glass, not a glass of latte. That would obviously work, too, but I have posted about that soo often by now that it isn’t as exciting any more ;-)), two coffee crema and then pour a little milk in. Voila: diffusive layers form! That’s a really nice example of double-diffusive mixing where heat and milk diffuse at different rates. And if you disturb the stratification, for example by moving the glas, you get internal waves!
Fascinating how different people have such different perspectives on water.
Mine today was one I am not very familiar with: mainly through microscopes, trying to adjust them in such a way that visitors at the #loveyourocean booth of @deutschemeeresstiftung could get a good look at plankton. This would then lead the conversation to food webs, microplastics, and more. Very different from my usual topics, but definitely fun!
Also: taking pictures with your phone through a microscope is a lot more difficult than you would imagine!
(Yes, I know there are microscopes that take proper pictures…. But where is the fun in that?!)
Pretty impressed by the effort people at #bootdusseldorf2020 put into creating fun environments to try different water sports. Indoor pools with wind machines, live grass and bushes and stuff! And also impressive how different the moods are in different areas of the congress center. Pity it’s already over for me!
Also super awesome: the THW‘s rescue divers. And how air bubbles rapidly increase in volume as they rise to the surface :D
For this month’s #SciCommChall, I show you the contents of my trusty handbag. You see it in the picture here and in my profile picture. Wherever I go, it goes. And there are surprisingly many things in there that I carry with me for my #SciComm! Check out the blogpost!
Not really wave watching, but close enough: the light installation on this church’s steeple shows how low the cloud cover was two nights ago. Looks very cool, me thinks! Even cooler than on clear nights where you don’t get the projection on the clouds and the light just disappears into space (or wherever)
Yay! A little #WaveWatching on my way to a meeting in Berlin. Can you see which direction the waves are coming from? Check out how the ring waves are traveling from the buoy!
On a work trip, combining scouting locations of interest in terms of #biodiversity with (surprise!) #wavewatching. Luckily the duckies were cooperating and making interesting waves in their feeding frenzy. I especially love the splashing as the jump up and down the stone edge of the pond!
I think these ducks are so pretty! Remind me of a tiny figurine I owned as a child and that — I remember that vividly — had a glued-on part where something had broken off when it fell down…
And that’s it for this week’s #WaveWatchingWednesday! See you next Wednesday! :-)
For #WaveWatchingWednesday: A collection of pictures that I took (and shared on my wave watching Insta @fascinocean_kiel over the last week. For some reason with a lot more commentary on here than on Insta itself, don’t know why. Maybe because I am writing this while it’s still dark outside and I am waiting for it to get light so I can go do some wave watching? ;-)
Nothing makes me instantly as happy as looking at water. Especially blue water, but any water will do. This picture below? That’s what happiness looks like for me. No matter what else is going on in my life, this view instantly makes me feel calm and content. And happy. What is it for you that has a similar effect on your emotions?
And I discovered a new perspective that I am a little obsessed with right now. Right where I live, there is a big art piece out of metal that looks a little ship-wreck-y and very nautical (it’s called “Hafen 77” by artist Felix Fehlmann). It has circular holes in it, reminiscent of portholes, but it never occurred to me before to use them to frame pictures in. This is my fist attempt at it — what do you think?
Now that I have discovered that porthole view, I wanted to go back the next morning to take a picture with different lighting. Unfortunately I was 2 minutes late to catch the Sweden ferry through the porthole! I hadn’t thought about how that would make a great picture until I saw her and it was already too late. But luckily there are more ships going in and out Kiel port, so there will be another chance!
To keep my Instagram feed looking nice I couldn’t post the next porthole pic right after the first one, but luckily there was pretty cool wave watching that morning, too!
This is a picture of several ducks’ wakes: see how they are forming 2D Mach cones with the ducks at the tip? Taking pictures of waves is always best around sunrise and sunset, because then the contrast between a light sky and dark land helps show the wave structures as differently sloped parts of the waves reflect different parts of the high contrast surroundings.
Here is the mystery spot again (well, mystery for Instagram, I already wrote above that this is the “Hafen 77” art by Felix Fehlmann, so you already knew).
But this time also “zoomed out” so people can figure out where this is!
Sylt, an island on the german North Sea coast, is amazing for wave watching. But amazing waves come at a great cost: the nice sand beaches are threatened by coastal erosion and have to be protected and maintained with huge efforts.
On our mini-excursion, we saw many different measures for coastal protection, like tetrapods (those gigantic four-legged concrete structures) and different kinds of wave breakers.
I took 625 pictures (ok, mainly of waves, but also a lot of the ongoing coastal protection construction works!) that I won’t manage to sort through tonight, so this is your chance: which coastal protection structures should I write about first? (All the following pictures belong to this blog post until the next text interrupts the flow ;-))
It’s really difficult for me not to watch the spectacle of the Oslo ferry making a U-turn in the narrow Kiel fjord before backing up into its berth. So difficult, that I took my conference call to the roof terrace and my colleague asked if I was swimming in the sea because apparently that’s what it sounded like on the other end. So ferry-watching was unfortunately cut short.
But watching the ferry wasn’t my main reason for visiting Geomar, see below what we were up to: Torge and I presented a seminar on “It’s always a great idea to play! Teaching ocean and atmosphere dynamics with rotating tanks” (or similar, can’t remember exactly ;-)) We gave a short presentation and then invited everybody “to play”. We had four rotating tables set up, each prepared for a different experiment. And people seemed to enjoy doing hands-on experiments a lot. So hopefully there is a lot more playing with a lot more players in our future! :-)
And then a little more about that amazing day trip to Sylt:
Why is there so much foam on the beach? Two factors are playing together here: Breaking waves trapping air under water that tries to get back up and out, and dissolved organic matter lowering the water‘s surface tension. Both have to be present at the same time: if the water was calm and no waves were breaking, there wouldn’t be a way to get air into the bubbles of the foam because no air would get underneath the water. And if the surface tension wasn’t lowered, the bubbles wouldn’t be able to exist, they would just collaps into drops of water.
Pretty counterintuitive that one has to lower surface tension to make bubbles that are stable, isn’t it?
(Next four pics show different foam situations on the beach)
The year started off in the very best company — watching ships and waves and flowers with Astrid!
But of course there is also actual wave watching happening: Here we see a ship’s wake arriving. I find it fascinating how there are the stripes where you can look into the water and then those where you can’t! Total reflection in action. When I learned about that in physics class I never thought that was a phenomenon I would ever see in real life!
When the waves from the picture above meet the curved sea wall, they get reflected into this pretty pattern.
Another day, foggy and very windy! That day, my focus was on how there are no waves in the lee obstacles. Only after sufficiently long fetch do waves start to grow.
See how the surface roughness changes with distance from the obstacle?
Oh, and then there was a sunny day! The Oslo ferry is leaving in the distance. See the stripes in different blue tones? In the foreground you can see how the colors are related to surface roughness. Areas that are more exposed to wind are rougher with more waves and different wavelengths, and look darker. More sheltered areas in the lee of structures have fewer waves and appear in a lighter blue.
Oh, and then I had a great day with my nephew in the port of Hamburg with harbour boat trips, walks on the beach, and tons of wave watching. He was very impressed by my skill to know how far each wave would run up the beach, especially since we saw lots of people who either ran away screaming or got wet feet :-D
Another picture from the same day with my nephew: Here is a wave train from a ship’s wake arriving at the beach. I love watching this kind of stuff!
And then one day, I went#WakeWatching! On all three pictures below, you see waves made by the same little ferry. On the right is the turbulent wake where the ship just moved through the water, and on the left some of the feathers that form the V.
Here the ship is turning so we see water that is disturbed by the ship moving through, but doesn’t have the „boiling“ like where the propeller stirred up everything.
Now we see how the wind waves seem to be bunching up at the boundary between the wake and the area that wasn’t affected by the ship moving through.
Then, for #SciCommSunday, I posted a picture of a book that I think is a brilliant introduction to the science of communicating science that I also wrote a blogpost on.
And surprise: Bonus pic for my dear readers that I didn’t post on Instagram but that I think is cool (will definitely experiment with this kind of pictures more! Except panorama mode does weird things to waves, so on second thought maybe not…)
What we are looking at in the picture above is a really low-water day in Kiel. Which leads to interesting wave watching opportunities!
See how waves that arrive with straight crests somewhere offshore get bent as they reach the shallow water? That’s because the velocity of a wave depends on water depth. The deeper the water, the faster the wave can move. The shallower the water, the more the wave is slowed down. Therefore, waves get slowed down first in regions where the water is shallower, and the parts of the wave crest that are still in deeper water wrap around the shallower part. Kinda like when you are slipping on an icy road, you fall in the direction of the foot that didn’t slip because your body spins in that direction.
When there is really low water in Kiel fjord, we can observe the influence of topography on waves much better than we usually can! For example here we see how on one part of the “beach”, there are several wave crests behind each other, all breaking, whereas on the other part on the other side of the headland there is only one wave crest at the water’s edge. Why is that?
Wave crests get steeper and start to break when the water is shallow enough for the wave to “feel” the bottom. On the left side of the picture, depth is increasing faster towards the open ocean: The wave only feels the bottom right before it has reached the water’s edge. On the right side of the picture, on the other hand, the depth changes very gradually. Therefore waves feel the bottom already much earlier and many wave crests are steepening, preparing to break and finally breaking at the same time.
And then I just thought this picture was fun :-)
And a rainy day at work!
I actually don’t mind all the rain: It makes the flow in all the storm drains so much more interesting! Here we see how water shoots out of a pipe into a little lake. Note that I’m saying the water is shooting rather than flowing: That means that it is moving so fast that any disturbance is washed away with the water.
As the water shoots into the much slower flowing lake, it pulls water from the sides with it. This water obviously needs to be replaced from further away, so a recirculation is set up.
Here is an annotated version of the picture to see the recirculation going on: