Still the same evening as in the three previous posts, still windy, but now also getting overcast again. Still love our wake!
And fun bonus in the sea full of white caps: This really cool pirate ship (or whatever it is supposed to be). Looked a bit like the Black Pearl in this weather…
Unfortunately we were so much faster that it didn’t stand a chance. Also: Look at how the wind is blowing our wake over!
Just as quickly as it had gotten dark, the sun came out again. Love how the left side of the picture below looks like the colors are inverse with the dark sky and bright sea!
Below, we are looking at our own wake again, and at how the waves are breaking. I could watch this for hours! (Which reminds me — I probably have hours of movies of this. But not for today…)
The sea state has changed from when we first left port — not only are we not in Kiel fjord any more and therefore a lot more exposed to the wind, also the wind has picked up quite a bit.
The sea is starting to look quite cabbly…
And there are some white caps here and there.
Looking upwind, we also see stripes that remind me of Langmuir circulation, except I don’t think it’s fully developed at that point.
Great contrast between the blue skies and the white caps on the sea!
And, since I was smart enough to wear rain gear and stay on deck while the weather wasn’t quite so pleasant earlier, I got the very best spot when the sun came out again :-)
Yesterday, I went for a quick walk up Fløyen and really enjoyed it, despite the view being slightly different from what is usually shown on the postcards.
Nice, some wake watching!
I like walking through a forest and then occasionally getting glimpses of the city and the fjord!
Although the glimpses became less and less clear the higher up I went.
Up top there wasn’t much of a view left.
But I like the almost mystical mood in the fog and clouds!
And I like how in Bergen, there is wave watching at all kinds of different heights. Like here on the fire water pond as well as the wake of that incoming ferry in Vågen.
Or in my favourite puddle!
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:
Since it’s raining today (finally! I can’t be distracted by good weather all the time!) it’s time to post some Bergen pics! And yes, Kristin, they are all water-related. Sorry not sorry!
I don’t know how many of these I’ve taken over the years, but I still like this view!
And apparently I am really into reflections in puddles right now.
Next day with more sun shine! It really looks like fall already, doesn’t it?
Gotta love the low clouds (at least if cloud cover isn’t more than in this picture ;-))
And gotta love the port.
Somehow the water on these chairs was really fascinating to me.
Ha. When I vacated my seat here, some tourists were very happy to take it over from me.
Clearly they hadn’t seen what I saw, or they didn’t realize how quickly that rain front would move in… :-D
Sailing out of the Kiel fjord on a large ferry changes the whole perspective on the coastline. For example below, we see the lighthouse Friedrichsort which is located at the end of a headland and which is always an interesting spot for wave watching.
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…)
This is seriously one of the easiest tank experiments I have ever run! And I have been completely overthinking it for the last couple of weeks.
Quick reminder: This is what we think hope will happen: On a slope, melt water from a dyed ice cube will sink, creating a Taylor column that will be driven down the slope by gravity and back up the slope by vorticity conservation, leading to a “westward” movement in a stretched, cyclonic trajectory.
We are using the DIYnamics setup: A LEGO-driven Lazy Susan. And as a tank, we are using a transparent plastic storage box that I have had for many years, and the sloping bottom is made out of two breakfast boards that happened to be a good size.
Water is filled to “just below the edge of the white clips when they are in the lower position” (forgot to take measurements, this is seriously what I wrote down in my notes. We didn’t really think this experiment would work…)
The tank is then rotated at the LEGO motor’s speed (one rotation approximately every 3 seconds) and spun into solid body rotation. We waited for approximately 10 minutes, although I think we had reached solid body rotation a lot faster. But we had a lot of surface waves that were induced by some rotation that we couldn’t track down and fix. But in the end they turned out to not matter.
To start the experiment, Torge released a blue ice cube in the eastern corner of the shallow end. As the ice cube started melting, the cold melt water sank down towards the ground, where it started flowing towards the bottom of the tank. That increased the water column’s positive relative vorticity, which drove it back up the slope.
This was super cool to watch, especially since the ice cube started spinning cyclonically itself, too, so was moving in the same direction and faster than the rotating tank.
You see this rotation quite well in the movie below (if you manage to watch without getting seasick. We have a co-rotating setup coming up, it’s just not ready yet…)
Very soon, these amazing meandering structures appear: Rossby waves! :-)
And over time it becomes clear that the eddies that are being shed from the column rotating with the ice cubes are constant throughout the whole water depth.
It is a little difficult to observe that the structure is really the same throughout the whole water column since the color in the eddies that were shed is very faint, especially compared to the ice cube and the melt water, but below you might be able to spot it for the big eddy on the left.
Or maybe here? (And note the surface waves that become visible in the reflection of the joint between the two breakfast boards that make up the sloping bottom. Why is there so much vibration in the system???)
You can definitely see the surface-to-bottom structures in the following movie if you don’t let yourself be distracted by a little #HamburgLove on the back of the breakfast boards. Watching this makes you feel really dizzy, and we’ve been starting at this for more than the 8 seconds of the clip below ;-)
After a while, the Taylor column with the ice cube floating on top starts visibly moving towards the west, too. See how it has almost reached the edge of the first breakfast board already?
And because this was so cool, we obviously had to repeat the experiment. New water, new ice cube.
But: This time with an audience of excited oceanographers :-)
This time round, we also added a second ice cube after the first one had moved almost all the way towards the west (btw, do you see how that one has this really cool eddy around it, whereas the one in the east is only just starting to rotate and create its own Taylor column?)
And last not least: Happy selfie because I realized that there are way too few pictures like this on my blog, where you see what things look like (in this case in the GEOMAR seminar room) and who I am playing with (left to right: Torge, Franzi, Joke, Jan) :-)
