Category Archives: other

Southern Hemisphere fascination.

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How everything works the wrong way round in the Southern Hemisphere.

You have probably noticed how on this blog we’ve been super careful about always maintaining Northern Hemisphere rotation when talking about Ekman spirals, Kelvin waves, inertial oscillations – anything that is influenced by the Earth’s rotation. Well, today we are going to take the leap and are finally starting to talk about the Southern Hemisphere. Continue reading at your own risk!

As you know, on the Southern Hemisphere everything works the opposite way from how it works on the Northern Hemisphere. This leads to the most astonishing effects. Ekman spirals turn left. Kelvin waves need the boundary to their left to propagate. Inertial oscillations oscillate counter-clockwise.

But the most astonishing thing is: it doesn’t stop there! A little-known fact is that even diffusion works the other way around there. So imagine you had a container filled with water, and you had dyed different portions of the water in different colors. If you put small bottles in the water and waited for long enough, the dye would eventually separate from the water and move itself into those small bottles! Don’t believe me? Here is proof:

Where did you think all the food dye bottles that we can buy on the Northern Hemisphere originally came from? It’s like hamburgers – they don’t grow on trees. Some people make their living by very carefully removing the freshly filled dye bottles from the containers, drying them on the outside and labeling them. The remaining water in the container can now be used to water your plants with to make the hamburgers grow faster.

Oh wait, you still reading? Happy April Fools’ Day!

Advection fog

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When warm, moist air is advected and brought in contact with colder surfaces.

Recently I’ve been starting to think about a course I’ll be teaching later this year, and how it would be cool to have household examples for most, if not all, of the topics I’ll be talking about.

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Fogged up bathroom window

So this is one example for advection fog: Warm, moist air moves against a cold window and condenses.

Of course you can also observe this over other cold surfaces, for example over the ocean:

In the movie below you can witness how the iceberg slowly vanishes as the fog closes in on the ship.

It can actually get pretty spooky.

On this picture you can clearly see that the fog is confined to a shallow layer directly above the ocean’s surface. We were standing on the deck above the bridge, and there we were up high enough to see that it is indeed a thin layer and that the skies above are blue. From the working deck it felt like fog had swallowed us up and the Black Pearl was about to appear…

Blogging as a tool for professional development

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How I see blogging as helpful tool for my professional development.
Before I go into how blogging helps with my professional development, there is one very important fact that I want to state very clearly: This blog is first and foremost a hobby that I do in my free time for my own pleasure, because it is the greatest excuse of all to just play with water and dye and all the other things I want to play with.
But I have come to realize that blogging is a tool that can totally be used for professional purposes, even when done in a very low-key, non time-intensive way like this blog is.
So what are the advantages of blogging for me?
Blogging made me more aware of everyday examples of oceanographic processes that I could use in class. After I began blogging, I started noticing everyday concepts that can be related to oceanography a lot more consciously. Looking at puddles, I noticed how waves moved on them or ice formed. Looking at a spoon in a glass, I noticed refraction in different media. I would probably have noticed those things before, but only in passing, and I would have forgotten about them 10 seconds later. Now, I stop, take a picture with my phone, and spend a couple of minutes writing a text about them after I get home that night. This little extra effort helps me in two ways: Being aware that this specific example could be useful in future teaching, and actually having a documentation that I can build on in my class (i.e. my blog post and a couple of pictures). Plus I really enjoy noticing oceanography everywhere.
Another advantage of blogging is the community it provides. This sounds funny seeing that I write blog posts alone at home, but blogging has opened a new community that is interested in talking about teaching and/or oceanography (in many cases in both, but with different degrees of interest in either of the two). So many people read what I post, and talk to me on the corridor at work, via email, when I meet them in person, in all kinds of settings. Apart from occasionally sharing pictures of cool experiments on facebook or dragging friends down to the lab, I did not have that kind of community available to exchange ideas with before I started blogging.
In addition to giving me community in my peer group, blogging has made me a lot more visible to colleagues both at my institution and at other institutions as someone who is interested in teaching, and more importantly, in discussing teaching and striving to improve it. This has already now, a couple of months into blogging, lead to invited talks. And I am hoping this trend will continue!
And then blogging helps me to make time to reflect about topics tangentially related to my teaching that I want to spend time thinking about, but would not make time for if I was “just thinking” rather than sitting at my desk and writing down my thoughts in a semi coherent manner. Now I jot down topics in a designated spot as they pop up in my head, and make time for most of them the weekend after, or the one after that. Even just writing down random topics I want to think about would not happen if it wasn’t for my blog, so this point is one that I really enjoy about blogging.
As an addendum to the previous two points, blogging ensures I have thought about a topic at enough depth that the critical readers (yes, they are out there! and they are giving me feedback!) don’t find huge holes in my reasoning at the very first glance. Calling this peer-review is an overstatement, but at least it gives me some sort of feedback mechanism before I walk into a class and test new materials.
How about you? Are you blogging? Then please point me towards your blog! Are you not? But are you interested in a guest post here? Let me know and we can set something up!

Call for Papers: Teaching STEM Principles through Oceanography Content

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The Journal of Geoscience Education (JGE) is soliciting manuscripts for a themed issue on Teaching STEM Principles through Oceanography Content. 

And I am one of the guest associate editors!

Check out the call for papers below and consider submitting to this special edition. It is going to be exciting! :-)

If you have any questions about this special edition, please don’t hesitate to get in touch!

Help the Earth Science Women’s Network become a non-profit!

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Support ESWN’s fund-raising campaign.

I have been a member of ESWN for many years, on the European board since 2010 and on the Leadership Board since 2012, so clearly I think it is a worthwhile cause to support. Through ESWN, I have met many amazing people, formed friendships, found support, started collaborations, received peer-mentoring, attended workshops and much more. If you haven’t joined yet, check out ESWN at ESWNonline.org. And please consider supporting ESWN – details on the campaign here or behind the cut.

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Defying gravity. And Happy New Year!

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Today I was browsing for a new laptop bag online and came across this page (and I am neither affiliated nor anything else with them, as will hopefully also become clear in about a second)*.

They give a lot of advice on what to look for in a laptop bag, but there was one advice in particular that jumped at me and that I absolutely had to share with my dear readers:

“A generously padded laptop bag can also release some weight because it “holds” your computer up from the gravity.”

Isn’t this awesome? I like it so much I have to repeat it:

“A generously padded laptop bag can also release some weight because it “holds” your computer up from the gravity.”

I’m thinking about buying two so I can sit on one of the generously padded bags (sounds comfy, right?) while flying alongside my laptop, which will be safely stashed in the other generously padded one. And all the time we will be held up from the gravity!
Clearly, there is still a lot of physics education left to be done in 2014! I’ll be back with regular postings and tons of new experiments on Monday. Until then – Happy New Year!
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* and I am especially not responsible for their content, as I am never for external links… ;-)

Happy Nikolaus day!

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To those of you who polished their boots last night, put them outside their door, and then were all excited this morning: Happy Nikolaus day!

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Håkon Mosby arriving back in Bergen in November 2013. How is this for an Advent calendar picture?

To everybody else: It’s clearly time to politely remind the Germans in your life that they should keep this coolest of traditions alive. You best do this by running to the shop, grabbing some chocolates, putting them in their shoes with a small card and maybe a tiny branch and waiting for them to find it. Oh, and nuts or oranges work well, too. Happy Nikolaus day!

Langmuir circulation, take 2

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Attempt at mechanistic understanding of Langmuir circulation.

After  complaining about how I didn’t have mechanistic understanding of Langmuir circulation recently, and how I was too lazy to do a real literature search on it, my friend Kristin sent me a paper that might shed light on the issue. And it did! So here is what I think I understand (and please feel free to jump in and comment if you have a better explanation).

First, let’s recap what we are talking about. My friend Leela (and it was so nice to have her visit!!!) and I observed this:

Long rows of foam on the surface of the fjord, more or less aligned with the direction of the wind (we couldn’t tell for sure since we were on a moving boat, and since it was a tourist cruise we couldn’t ask them to stand still for a minute to satisfy our oceanographic curiosity). Foam is – and so much makes sense – accumulated in regions of surface convergence.

But let’s see. The explanation that Kristin forwarded me is from the paper “Upper ocean mixing” by J.N. Moum and W.D. Smyth for Academic Press Encyclopedia of Ocean Sciences, 2000. According to my understanding of their paper and others, Langmuir circulation is related to Stokes drift.

Stokes drift is the small current in the direction of wave propagation that is caused by orbital wave motions not being completely closed (even though they are as a first order explanation, and that’s what you always learn when you think about rubber ducks not being laterally moved by waves).

As the wave orbital motions decrease with depth, there is a shear in the Stokes drift, with strongest velocities being found at the surface. At the same time, if there are small disturbances in the wind field, there are small inhomogeneities in the resulting surface current, hence shear that generates vertical vorticity.

The combination of horizontal and vertical vorticity causes counterrotating vortices at the ocean surface. The convergences between two adjacent rows concentrate the wind-driven surface current into a jet at the convergence, hence providing a positive feedback.

Voila: Stokes drift!

Traveling circus

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Stuff that I  brought to Isafjördur to teach the intro to oceanography.

I’ve been a fan of minimalistic travel for a while. And apparently I was ready for a new challenge: Minimalistic travel but with the full equipment for experiments in oceanography! Sadly I didn’t manage to carry on even though I tried…

Stuff that I’m bringing with me to teach “intro to oceanography”.

It might not look like too much, but you’ll be pleased to know that with this equipment, I can show every experiment I’ve shared on this blog so far (with the exception of the ones in the long internal lee wave tank) plus at least a dozen or so that are still in the pipeline to be published on here (I have lost track of what I have shared and I’m too lazy to look it up now, sorry).

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Granted, I did send a list of stuff that I’ll need to Isafjördur, too, and asked them to organize those things for me. But on that list there are only things like paper towels, empty 1.5l bottles or matches – hence things that are very easy to obtain anywhere, but a pain to travel with. I’m bringing all the fancy stuff like high-intensity non-toxic dyes, modeling clay, clear straws (surprisingly difficult to find!), split pins, wooden tongs, heating&cooling pads, an inflatable globe and many more.

So who wants to invite me to come teach at their place? I also “train the trainers” if you want to learn how to do all of this awesome stuff and then teach your students yourself!