lee waves – Adventures in Oceanography and Teaching

Lee waves with an asymmetrical “mountain”

mglessmer — Thu, 25 Oct 2018 09:20:38 +0000

How will lee waves look differently if we are using the asymmetrical mountain instead of the symmetric one? And is symmetry actually important at all or are we just looking at different slopes downstream while the upstream slope doesn’t have an influence on the wave field? After admitting I had only ever used the symmetrical […]

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Instructions: Lee wave demonstration in the GFI basement

mglessmer — Wed, 24 Oct 2018 08:20:48 +0000

This blog post is meant as guideline if someone other than me might have to set up this demonstration at some point… Have fun! :-) Lee waves Lee waves are the kind of waves that can be observed downwind of a mountain in the clouds, or downstream of an obstacle in a current as a […]

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Tank experiment: Lee waves in a fancy density (and dye) stratification

mglessmer — Thu, 16 Aug 2018 16:20:45 +0000

Did you seriously think we’d stop tank experiments with only 2-layer systems? Nooo! Today, the plan was to set up a continuous stratification, which I have been planning to do for many years. After fiddling with the setup all morning (do you have any idea how many fittings on all kinds of hoses are needed […]

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The one where it would help to understand the theory better (but still: awesome tank experiment!)

mglessmer — Thu, 16 Aug 2018 15:47:11 +0000

The main reason why we went to all the trouble of setting up a quasi-continuous stratification to pull our mountain through instead of sticking to the 2 layer system we used before was that we were expecting to see a tilt of the axis of the propagating phase. We did some calculations of the Brunt-Väisälä […]

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Dead water — the fancy experiment including Nansen himself

mglessmer — Thu, 16 Aug 2018 15:47:05 +0000

Now that we do have a really awesome 12-layer 6-color stratification, we obviously had to do the dead water experiment again. This time we chose to include a not-too-happy-looking Nansen on the ship, too! I love this even more than the one we did yesterday!

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Lee waves in the tank

mglessmer — Wed, 15 Aug 2018 19:18:57 +0000

Did you guess what we needed the stratification for? Yes — we are moving mountains again! :-) What we want to look at: How a current reacts to an obstacle in its way, especially a current in a stratification. But since it is really difficult to set up a current in a tank, let alone […]

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Wake of a house.

mglessmer — Mon, 28 Apr 2014 05:30:01 +0000

Am I weird for noticing that kind of stuff? When I posted that picture of the fountain in the last post, it very strongly reminded me of a breakfast my sister and I had in Shetland in 2009, where the flags on the two poles outside the window were blowing towards each other (clearly caught in the wake […]

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Details of lee waves in the tank.

mglessmer — Sat, 21 Sep 2013 03:25:47 +0000

A movie focusing on details of the lee waves in the tank. In this post, we investigated lee waves in a tank in a general way. Here, I want to show a detail of those lee waves: [vimeo 51662796] In this movie, the concept of hydraulic control becomes visible. On the upstream side of the […]

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Surface imprints of internal waves

mglessmer — Fri, 20 Sep 2013 04:16:24 +0000

How internal waves in the ocean can be spotted on the surface. Under certain conditions, internal waves in the ocean can be spotted at the ocean’s surface due to changes in surface roughness or to the movement of floating foam or debris. They can be spotted if half their wavelength is longer than the distance […]

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Internal (lee) waves in a tank.

mglessmer — Thu, 19 Sep 2013 04:59:12 +0000

Lee wave experiment in a large tank with a moving mountain. In this previous post, we talked about internal waves in a very simple experiment. But Geophysical Institute has a great tank to do lee wave experiments with that I want to present here (although it doesn’t seem to be clear what will happen to the […]

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