What I find really fascinating about watching waves in the atmosphere rather than on water is that all the waves that become visible are not surface waves like on water, but internal waves. Which we have to go to great lengths to make visible in water (for example by adding dyes in tank experiments) but which we can’t just visually observe in the sea in the same way as we can in a transparent atmosphere.
In the atmosphere, however, we also don’t see every internal wave going on, either, we need very specific conditions for them to become visible. So whenever I see one, I start pondering why we see exactly what we see, why there are clouds in some places and not in others. Below, for example, we see the troughs of an internal waves in cloud stripes, but the crests don’t form clouds. Fascinating how just displacing air by a little bit can cause clouds to form and to disappear!
And things become super cool when you combine atmospheric wave watching with “normal” wave watching like in the picture above. There you see the rough surface with tiny little wind waves in the background, waves coming around the break water, the calm water in the lee of the break water, sheltered from the wind, and then the reflection of the atmospheric waves on the water.
And you thought it couldn’t get any better? Well, you were wrong! Now there are also some waves on the water, plus soap bubbles! :-)
Now, for a thought experiment: What would soap do to the waves? Would destroying surface tension actually matter? I think not in this case, or t least not close to land in the picture above, since the waves are mainly gravity waves, not capillary waves. But what do you think?
Some throwback Friday evening wave watching (at the locks at Kiel Holtenau with my friend Sara for a nice and relaxing end of the week) to start the new week. The best!
First: The pilot boat going towards the locks. Unusually visible wake — they are going fast today! Plus an interesting sheltering of waves: The wind is coming towards us so outside of those floating pontoons are a lot larger than the ones on this side that haven’t had enough fetch to build up.
Below we see the same wake: But do you see how it’s just ending on the left? That’s because the pilot boat went in behind the jetty on the far side of the fjord, and it’s only these bits of the wake that were able to propagate outside before the boat went in and the waves don’t make it out of the small channel created by the jetty.
And below the pilot boat going out again in a curve: Love how you see the turbulent wake as well as the deformed V-shaped feathery wake. When you look from the pilot boat down on the picture, do you see the individual “feathers” of the V? Love this perspective on wakes!
And this is what you will see of me when you meet me for a coffee anywhere near water. Sorry Sara, but thanks for the picture! :-)
On a recent flight from Hamburg to London City Airport, I ended up on one of the tiniest planes I’ve ever been on. Which meant that we flew super low, I took tons of pictures out of a not-very-clean window, and all my pictures have at least one propeller blade in them.
But look at what we saw!
For example in the picture below, a plume of muddy water coming from some canal into a river (and I should probably know where this is, but I have no idea. Somewhere between Hamburg and London?). I’m not sure whether the inflowing water itself was muddy to begin with, but I would guess that it is stirring up mud from the bottom of the river since it seems to be low tide and the inflowing water is maybe moving a lot faster than the water in the river itself?
Closer to England we flew across this wind farm, where turbines have mud stripes in their lee. Also pretty interesting. Maybe they change direction with tides?
And then coming to the mouth of the River Thames, there is quite a clear front between outflow and muddy North Sea water.
Going upstream on the River Thames, boats stir up a lot of mud!
So you can clearly see where they went for a pretty long time.
On this flight, I sat next to a professional photographer who rolled his eyes at me taking pictures pretty much non-stop. And yes, they might not be the best quality. But at least you see what I saw, right?
I recently started looking at waves in “urban environments” (in contrast to “on the sea”) with a new found fascination. The reason why will be revealed soon, but for now just know that there are more waves coming up on this blog!
Today, let’s start by looking at more waves on Store Lungegårdsvannet, like we did before.
Here, you look downwind and see the flat water right in front of you, shaded from the wind by the walls around the lake. And then the further away you look, the larger the waves grow.
Another very funny picture of a similar situation below: See how parts of the lake’s surface reflect the buildings and mountains and clouds really well (since that part of the surface is really flat), whereas other parts are way too choppy and appear a lot greyer on the picture?
Yes, I admit, the purpose of this blog post was not so much to talk about waves as to show you how beautiful Bergen is in May. I miss this city… And my AMAZING Bergen friends!!! <3