The weather forecast wasn’t too good for the crossing, so knowing that I was going to do some hard core wave watching anyway, I put on my full rain gear right away. After all, there is no such thing as bad weather, only inappropriate clothing!
If you look at the clouds, you see that the weather had quickly turned to not-so-nice-anymore. The sea is still kinda calm, but look at how the higher waves in our wake get white caps — it’s clearly blowing a little!
And it was getting darker and darker.
And darker. I love the stark contrast between the straight turbulent wake and the shapes of the clouds.
Btw, looking down at the railing, the turbulence still looks fun!
And the sun is coming out again, at least in spots.
But the spots are growing larger… So all is well that ends well! Especially with such a beautiful wake (notice the feathers of the V, especially visible to the left of the turbulent wake?)
Oh look, someone built a perfect rectangular wave watching basin into Bergen harbour!
As you see above, waves are propagating towards this little wave tank and into it. They then get reflected at the edge at the bottom of the picture. Then, the original incoming wave and reflection propagate together further into the basin. They are now forming V-shaped wave.
This leads to this really cool interference pattern in the basin: Lots of seemingly disconnected little hills and valleys in a checkerboard pattern.
It looks even cooler when moving! Because it’s so difficult to track individual wave crests and the hills and valleys seem to just be appearing and disappearing randomly:
Or on the other side of Kiel fjord, Laboe is very popular with kite surfers. There are sand banks quite far out in the fjord and a very shallow area connecting the sand banks and the beach, so the water is usually calm and warm there.
It’s very interesting to see this not from sea level, but from higher up!
I recently traveled from Kiel to Bergen by ferry and train, and instead of doing one single monster post about it, I thought I’d try a mini series format. Let me know how that works out for you (but it’s scheduled for the next two weeks already anyway, so you’ll have to live with it for that long in any case :-))
Anyway, let’t get started. As I said, I traveled by ferry, but by neither of the ones you see below. What I found really interesting about the small ferry’s wake are the two turbulent stripes that are visible behind the ferry but that appear to be under water, and that aren’t a continuation of the foam stripes from the breaking bow waves. I have never noticed that before, have you?
And here some more ships as we leave the port of Kiel, notably the historic steam ship that Alice and I (accidentally) went swing dancing on!
I really like the perspective in the picture below: The bottom of the image is parallel to the side edge of our ship, and you see the turbulence we are creating as we are sailing (left-to-right).
And I love how you see the fast turn the sail boat at the top of the picture just did!
More of the same: The sail boat that turned has already sailed out of the picture (but you can still spot its wake in the upper left corner, as well as its reflection on the water), and the other ship as properly sailed into the picture.
The small boat there is making quite some waves in a beautiful wake! I love how you see all the individual feathers of the V-shaped wake with the turbulent wake inside of them.
And here is our own beautiful wake. Is it weird that I think it’s absolutely beautiful? Like some delicate lace or something.
Here we are looking down the railing again. We are going faster now, so the turbulence has changed and become more intense.
That’s a good start for today — catch you again tomorrow! :-)
They might not look like much, but when I spotted these in the street this morning, I was super excited: Roll waves!
I marked some of them below (just to make sure you see what I saw and not just a wet street) — lots of little groups of waves that fan out and propagate down the street in a fairly regular pattern, which is controlled by the amount of water going down, the slope of the street, and friction.
In the movie below we first look upstream and see a very regular pattern, and then downstream when it is raining a little more than shortly before, and there we see that sometimes one of the wave groups is a little larger and a little faster and eats up the one before.
How cool is that?
And here is an analogy of what happens: Everything is moving the way it should, until suddenly something moves faster and brings with it everything in front of it.
(Also, isn’t it funny what continued wave watching does to your brain? I cannot go anywhere without seeing waves these days…)
We are still in the “interesting weather” period here in Kiel. Feels more like April than like September, but I am not complaining. I love the rapid change between dark clouds and blue skies and sunshine! Also I like how much more interesting wave pattern get if the wind comes in gusts rather than blowing just consistently the same.
Below, you see strong gusts of wind in the dark areas with the high surface roughness, but you also see that the small waves in the foreground have higher amplitudes and more pointy peaks than we usually see. Additionally, there are longer wave length waves coming in with crests more or less parallel to the images lower edge. And on top of all of this, there is the seagull’s wake. Can you still spot it even though it’s superposed on all the other waves?
Below, you clearly see the different wind strength in different areas. The shiny, flat surface with lower wind speeds, the rougher areas, and the comparatively short waves with large amplitudes in the foreground that show that there really is a lot of energy input over a relatively short fetch.
Below, in some regions we can also see hints of a checkerboard interference pattern of longer waves that were reflected at the sea wall, with the small, short wavelength waves superimposed.
Here is another look at these waves. I find them so fascinating!
And below is another strong gust of wind visible. And do you see the wave crests parallel to the edge of the floating part of the pier, created by that part of the pier moving in the waves?
And, just in case you didn’t know: At the end of the rainbow, you will find a … research ship!
Luckily I had a nice spot from which I could observe what happened next…
…lots of drops. In the ocean. Or oceans in the drops? Who knows. Anyway, after just having done that drop drawing, I couldn’t very well get upset, and I love watching rain on water anyway.
Just look at all the wave rings, and the way drops are catapulted up again only through surface tension!
Here is a (first normal speed, then slow motion) video so you can appreciate it properly, too:
As the rain passed, I found it super impressive to watch the rain showers as they went down elsewhere.
Like over the mouth of Kiel fjord, and I am showing the same spot repeatedly in the following (with more or less the same view, you can use the buoy as point of reference).
I don’t know enough about meteorology to understand what’s going on there, but I can still appreciate the beauty of the rain cloud and how differently things look where it is propagating to (to the right) and where it has already left (to the left).
See how much lower the clouds on the right are, and clearly a different kind of cloud compared to the ones on the left?
At times, it got really dark.
And I watched this one cloud move, continuously raining.
Then there was a dry period of a couple of hours, and when I walked home, it looked like this: Again distinct areas with rain showers.
What I found also really interesting is the swimmer’s wake you see below. There is so much to see in that one picture: The wake, the rain shower in the background, the changing surface roughness from rougher, darker areas, and smoother, lighter areas, and then the areas in the foreground where we can look into the water (see here for why we can do that in some places and not in others)
Same thing as above, only in a different picture…
And again, this time with a really impressive black cloud. And interference pattern in the waves in the foreground.
And now even ring waves that that seagull made…
And as if I hadn’t had enough wave watching in one day, here is a different spot in the afternoon. See the interference pattern as waves get refracted around the bollard?
And, of course, another strong shower came and made us retreat to the inside. But see the rainbow in the picture below? Those are the kind of things that make me really happy! :-)
Even though I’ve been looking at waves for years now, wave watching is still full of surprises. Yesterday I showed you capillary waves that a jellyfish made, and today I’m showing you a helpful seagull.
What I found most fascinating walking through this marina were the long straight wave crests that form in parallel to the step in the foreground as waves leap up on the step and then the water flows back. I can watch this kind of thing for a very long time!
But I was also pointing out the ring waves around the bollards to my friend, which are a lot more difficult to spot. But, as if it had just been waiting for the opportunity to help out, the seagull on one of the bollards dropped something and created ring waves for us! Can you spot it?
Sometimes the best wave watching doesn’t happen how you expect it to happen. Look at this jellyfish, bobbing about in the surface of Kiel fjord. Can you spot the circular wave pattern all around where it breaks the surface? I find this so amazing. Would you have thought that you would spot waves that a jellyfish makes?
Btw, there are other places with capillary waves in this picture, too: In several spots you see thin wave crests, parallel to each other, running in front of a larger wave crest. Those are capillary waves, and the cool thing is that the shorter their wavelength, the faster their propagation. Therefore the larger crests seem to be pushing the smaller ones in front of them, bunching them up over time.
Early morning Kiel fjord — today even featuring a hot-air balloon!
But, more interestingly, the wake of this police boat. I find it already pretty cool in the picture below: The fjord is calm and mirror-like, but inside the ship’s V-shaped wake the surface changes completely and the reflections look totally different (now only reflecting the sky back, not the cranes). And, of course, the V-shaped wake itself has quite a large amplitude, too.
A little while later, the wake has not only reached the sea wall, it is already being reflected back away from the wall. See the original wake at the bottom of the picture below, and the reflection further away, near the five bollards?
Looking slightly further right, we see the concave shape of the sea wall here, and how waves are being focussed similarly to how radio waves are focussed towards the receiver with parabolic antennas.
So as the reflected waves propagate out further and further, they little by little reach a focal point.
Which you see in the picture below: An area of higher waves in the middle of the water, seemingly for no reason.
And the area where waves interfere and amplitudes are so high moves a bit over time, but it’s a quite persistent pattern.
Had I just come across this pattern without seeing it develop, I don’t think I would have been able to explain what is going on here.
And see how, now that the wake has passed, the checkerboard pattern of interfering waves in the foreground is a lot more prominent again?
