Tag Archives: snow

#WaveWatchingWednesday

Haven’t posted a #WaveWatchingWednesday in a while — but I am very regularly posting over on my Instagram @fascinocean_kiel. Check it out if you fancy a more regular supply of pics!

Finally a sunny day again! Which means that I HAVE to get outside. And voila: awesome #WaveWatching! See the waves radiating as half circles from a point source from the lower right corner? That’s a dog drinking!

This morning, there was only a super thin layer of ice on the pond — enough to trap small air bubbles in some spaces, but still flexible — and on it, the fern-like structures in which the ice grew were still visible. So pretty!⁠

Do you see the large ring waves on the left, where a duck is riding on the edge of the wave? It was caused by the three ducks reaching the “ice edge” (well, the edge of super thin ice floes that weren’t even connected) and the first duck deciding to fly to the next spot of open water, where it landed with a splash in the center of that wave, and then flew another wing flap or two to where it is sitting now, while the wave spread. But the ice the duck was avoiding explains why the wave looks so much smaller on its right side than on the left where the duck is! The ice also explains why it’s really difficult to see the wakes of the other two ducks on the right — all the waves are dampened away by the ice.⠀

Ice looks differently depending on the conditions it formed in. Here, supercold & calm water recently froze in long needles. If there had been waves, needles wouldn’t have been able to grow so long, slush would have formed and then pancakes. If there had been salt in the water, it would look more milky and less clear. If the ice had started melting and then refrozen, the structures of the needles would have gotten destroyed. Fascinating how much ice can tell us about what conditions must have been prevalent!⁠⠀

Ice needles are a prominent feature of freshly formed ice on calm puddles or lakes when the water is supercooled. They form all over, growing longer and longer, until they meet another needle. Only then do the spaces between needles start to fill.

No waves? No problem! (Thanks to these amazing #GreatWave mittens by @kjersti.daae ) And what looks like melt ponds on the ice here is snow falling on a more-or-less intact ice sheet. The more intact, the more snow. The wetter, the better — for wave watching Good thing it’s the weekend now!

There is enough water in this pic — in frozen form in the snow, and as tiny droplets in the fog — to warrant an appearance here. What a beautiful day!

Wet snow is definitely better than no snow. And even better when work meetings can happen on the phone and we can at least do virtual walk & talk meetings :)

This picture shows a puddle, that froze and got snowed on, then someone broke that snowy ice sheet and bits of ice got pushed into the water while others were pushed out (see for example the grey thing on the right). The puddle then froze again (all the clear ice you see) and hoar frost grew on some of the old pieces of ice (those needles you see. The long ones are longer than a centimeter!). And all of this in just one puddle!

I am fascinated with phase transitions at the moment. Here, snow fell on this bush. It then partly melted in the sun the next day, and the next night the liquid water refroze, forming an icicle.

Hoarfrost grew on a puddle the froze, broke open again, froze again⠀

Very distracting to work under a skylight… Turns out it is pretty difficult to take pics because they melt so quickly and it’s super difficult to focus on the right depth in between all the melt water puddles that have a much higher contrast!

More snowflakes! Here the same ones with slightly different tilt of the camera — against the bright sky vs thr dark tree. Such different results!

Too much snow on the skylight above my desk to look outside, so I had to actually go outside to look at snow. And it was so fluffy that one could really see individual snow flakes! How cool is that???

Albedo effects: where there is snow, it’s easier for more snow to accumulate because the white surface reflects incoming sunlight and stays relatively cold. Darker surfaces warm up faster, snow melts, surfaces remain darker, snow still melts more easily than on white surfaces… In this pic we see this both on a larger scale and on the micro scale in some animal’s footprints! Where the animal compacted the snow, it melted less than around it, so new snow accumulated on the old footprints but not around them. Therefore they stay visible for days!

More pretty snowflakes spotted “in the wild” <3⠀

Insta takeover on snowflake formation

Back in December, I did a takeover of the Instagram account of WissKommSquad, a community of german science communicators. I translated it over new years, but somehow never published it. I have since taken tons of much better pictures of snowflakes, but the story I’m telling here is still interesting, I think: How snow and ice form through different processes and why they look the way they do. Have fun!

(First an embedded version directly from Canva, which I used to produce the story, and then below the cut the individual pictures)

Snow Story @SWissKommSquad by Mirjam Glessmer
Continue reading

Kiel to Bergen, the mini series. Part 14, in which we are in the snowy part of Bergensbanen minutt for minutt

And now we’ve reached the heights where there is fresh snow! And also where there are wild rivers. Don’t know which I find more exciting :-)

Ok, yeah, it’s definitely the rivers that I find more exciting. Also, isn’t it funny that at first glance, the river seems to be flowing left-to-right, because that’s the direction in which the waves break? It’s flowing right-to-left, though, and the waves are breaking in an upstream direction because the water is just flowing so fast, it’s ripping the carpet out from underneath their feet, so to speak.

And now we have arrived in winter wonder land :-)

…where there is some new ice on the more sheltered parts of the lakes, too!

And now we on our way back down on the west side of the mountains. Snow only on the higher peaks, not at ground level any more.

And now it’s properly overcast and occasionally also snowing!

But let’s end this part of the journey with this beautiful outflow of the lake, and the standing waves that look as if they were braided into each other. So pretty!

Frost flowers on the ice of the Schlei in Schleswig. By Mirjam S. Glessmer

Frost flowers – when water vapour freezes to ice without going through the liquid phase. Examples “at sea”

Frost flowers! I learned about those in the context of Arctic and Antarctic ice formation. I kinda assumed that ice flowers only formed in salt water, because I remember hearing about how the ice needles that form wick up brine and that, due to their large surface (which you will remember noticing in the last post where we looked at them forming on trees), they are super important in the air-sea exchange of all kinds of stuff,  like for example bromine. So imagine my excitement when I saw them growing the other day!

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Frozen Schlei river in Schleswig

Frost flowers are really pretty by themselves, but they also tell us a lot about recent weather conditions. For example, they only form when the air is A LOT colder than the water/ice surface. Do you know the snowy ice crystals you sometimes find on the inside of ice cream containers when you’ve opened and refrozen them? Yep – same thing! I even suspect that the ice crystals I was talking about in this post are also frost flowers.

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Frost flowers

I find it really fascinating how they are distributed over the larger surface of the Schlei river.

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Schlei river in Schleswig coated in frost flowers

Here, for example, you see them forming on the edges of ice that has been broken up by some mechanical process. Judging from their placement, I would suspect that they only formed after the ice was broken and some of the pieces tilted up.

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Cracked ice and frost flowers

Here, they were probably everywhere, but then the ice got broken up and some parts submerged. When the water there refroze, no snow flowers formed, just “normal” ice. However, the existing snow flowers seem to have continued growing!

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Ice with frost flowers. Partially submerged and then refrozen into “normal” ice

The really interesting thing is that frost flowers don’t actually form from the water that is freezing below, but from water vapour in the air. Which, btw, explains why they can form on benches, ice cream lids or trees (all of which would be really difficult if they could only form on open water surfaces).

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Ice with frost flowers. Partially submerged and then refrozen into “normal” ice

Above you see a larger part of the Schlei’s surface: Seems like there used to be frost flowers everywhere, but when the ice broke up, some of it got pushed out of the water, and as such preserving the frost flowers and letting them continue to grow. Meanwhile, other parts got flooded and only normal ice formed there. Maybe because the temperature gradient at that point wasn’t large enough any more?

Isn’t this just beautiful??? I could watch this all day, every day.

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Frozen Schlei river in Schleswig with frost flowers

But let’s look at some more details. No idea why that patch of frost flowers formed there! But they seem to always start in small patches, which eventually grow together if the conditions are stable enough over long enough periods of time.

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Frost flowers on ice

Here, we see the opposite situation to the one a couple of pictures up: “Normal” ice had formed, and then was broken up. And then, when the crack froze over, frost flowers formed!

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Frost flowers growing in a crack in the ice

Very cool stuff!

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Frost flowers

Yep, I would still just sit there and watch!

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Frozen Schlei river in Schleswig

Frost flowers on the ice of the Schlei in Schleswig. By Mirjam S. Glessmer

Frost flowers – when water vapour freezes to ice without going through the liquid phase. Examples on land

What happens when water vapour freezes to ice without going through the liquid phase? Frost flowers!!!

That’s when trees suddenly look like this:

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Frosted tree.

Btw – the stem of that tree is painted white! That’s just to confuse you a little but…

But let’s take a closer look. This is what the branches look like: Tiny ice needles growing on the individual pine needles! And the orientation of the image below is correct. They are growing to the side!

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Frosted tree.

You can clearly see them all growing to one direction, to one side!

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Frosted tree.

When you take off a bit of frost, this is what it looks like. Needles, but with a fractal 3D structure! Since what happened here (water vapour freezing without becoming liquid in between) is basically snow forming on the surfaces down here instead of in the clouds up above, it isn’t too surprising that snow is exactly what the frost bits feel like.

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A piece of frosting. This picture isn’t blurry – the ice needles have a fractal 3D structure!

Look below, you can clearly see the frost only growing to one side (and this picture is the right way up, too!):

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Frosting on tree branches

Doesn’t it make you want to sit there and just watch?

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What a nice picknick spot!

Although every time the slightest of breezes comes, this is what happens:

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Tree being de-frosted by wind

Also really cool: These plants growing on a balcony behind a glass railing. Only the tips have been frosted!

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Plants on balcony with frosted tips

And if you were wondering what this post has to do with oceanography, check out the image below. Can you spot it?

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Frozen Schlei river in Schleswig

Can you spot it now? No, not my niece (although she is pretty cool, too!), the frost flowers!

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Schlei river in Schleswig with frost flowers

We’ll talk about those next time :-)

As frost starts melting, and the roof is getting dry, oh! The sun is up.

My office looks out directly onto the roof of our main lecture theatre, and it is fascinating how much you can observe just by looking out of a window and onto a roof.

Below is a picture of one of the first cold mornings we had this year. As the sun rose, more and more of the roof was lit and the frost melted away. Can you see where the shadow used to be just minutes ago from the shape of the still-frozen frost?

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Some time later, the first corner was completely dry, while other parts of the roof were still wet, the only-recently-lit parts of the roof still had frost n them, and some parts of the roof were still frosty in the shadows.

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I really enjoy making random observations that I bet most people wouldn’t even notice, but I take pictures of and write a haiku about. Good thing I have my blog :-)