On Saturday, 23/4 science and curious citizens of Bergen will occupy Marinerholmen in Bergen where the fair “OPPLEV” will take place. Together with the FJO2RD and CLIFORD team from the Bjerknes center I will use a fortune wheel, Lego, and candy fish to explain and illustrate deepwater renewals and de-oxygenation in Norwegian fjords… want to find out how? Then join us at Marinerholmen! (or stay tuned for an upcoming report here later!)
Last summer, we were excited to learn that the deep water of Masfjorden had finally been renewed – the deep fjord basin was replenished with new, oxygen-rich water, making it a much better place for fish to swim around in. We were equally excited when we headed up to the fjord last week (together with the paleo oceanographers), to recover the moorings that have been standing on the sill and in the deep basin for almost a year now. We were finally to learn more about when and how the renewal actually occurred!
The moorings were recovered without problems, and all looked good until Algot was to display the data on the screen. Were we expected to see the wiggly line displaying the current-meter record, revealing the strength and length of the renewal episode – there was only a straight line. Zero. A whole year of zeros, nothing but zeros. All the other sensors worked fine… but for some, still unknown reason, the velocity record was missing… the one record I had looked so much forward to seeing!
When it rains, it pours – especially if you are in Bergen. The second disappointment was waiting for a bit further into the fjord – one of the instruments that were supposed to record oxygen concentrations (and salinity and temperature) had leaked through a defect connector. The instrument (which is quite expensive) is ruined and the data is gone…
I guess we will just have to hang around another ten years or so for the next deep water renewal in Masfjorden 🙁
Snow, rain, and wind… the weather forecast was everything but promising when I left Bergen harbor together with a team of excited scientists last week onboard Kristine Bonnevie, our research ship. She headed northward towards the nearby fjords “Lurefjorden” and good old “Masfjorden.” The gear on deck was slightly different from what I am used to; the familiar mooring buoys and instruments boxes were accompanied by what I soon learned is called a “multi-corer” and a “gravity corer.”
These strange-looking creations are designed to collect mud – or sediments – from the ocean floor. As the sediment deposits chronologically, one layer at a time, they form an archive of the past. The deeper into the sediments you dive, the further back in time you go. Remnants of marine life deposited on the bottom – microscopic shells from foraminifera, for example – have incorporated information about the ocean properties at the time when they were living. Advanced bio-geochemical analyses can bring that information back. Or you can identify the shells – different species thrive in different conditions, some when there’s a lot of oxygen in the basin, others when there is little. If you know how to interpret the signals – you can turn what to most people looks just like mud into a historical record of fjord hydrography and learn how the oxygen concentration in the fjord basins has changed in time. To me, mud is mud, but luckily, we had Irina, Stijn, Agnes, and Dag-Inge, on board. They are paleo-oceanographers; they know how to turn mud into exciting science!
I almost forgot Mattia – our fresh PhD-student who arrived a couple of weeks ago to chilly and rainy Bergen from sunny Sicily. He will be working with the mud for the next three years.
Want to know how to involve students in the design of your oceanography class and to “co-create learning” – then read Mirjam and Kjersti’s recent paper “Co-Creating Learning in Oceanography“. They explain how to climb the ladder from “teacher controls everything” towards “student-staff partnership”, where the students have full control of their own learning. How far up the ladder you want to climb is up to you – and the students – but Mirjam and Kjersti give easy-to-include and adapt examples all along the way!
I’ll be teaching again this spring – helping Mari with the course in fjord oceanography – we’ll see where on the ladder we end up, but it sounds like a good idea to have the students determine the topic of their term papers based on keywords that Mari and I provide!
So – the defense is over – Eli did a splendid job presenting and defending her thesis and she can now put a “Dr” in front of her name! Congratulations Dr. Børve!
I’m happy with my contribution – although I keep wondering when I will stop being nervous (Eli on the other hand didn’t seem nervous at all, but “calm as a fridge”, as we would say in Swedish). I do realize that being nervous is such a waste of energy – but how do you stop?
Afterward, I found an e-mail from a colleague who had watched the defense in my inbox, telling me he thought I had done a good job. That one line was very much appreciated – we should write more e-mails like that!
Eli has done an impressive job during the last couple of years, working with high-resolution models to study non-linear effects of tidal flow in the many straits of the Lofoten archipelago. I’ve learned a lot while reading her thesis, and I can assure you that it is much more exciting than it may sound! If the tidal current is strong enough, and if the strait opening is abrupt enough – then two vortices may form, one on each side of the strait, that “auto-propagate” (i.e. they move faster than the background tidal current) far enough from the strait opening that they are not caught by the currents when the tide turn. When this process (“tidal pumping”) is at play the transport through the strait, from e.g. the spawning ground of Cod on one side to the open ocean on the other side, is much greater than if the tides were just moving the same water back and forth… pretty cool!
Much of Eli’s work is already published – and I’m sure she will do just fine tomorrow!
Hopefully, I’ll do too… although I’m admittedly a bit nervous!
(and if you want to learn more about tidal effects on ice shelf melt in Antarctica (guess who came up with the topic!) – then have a look at Eli’s trial lecture here! )
My Python enthusiasm was severly damaged yesterday as I (after a lot of head-scratching) realized that it is not my programming that makes things look strange, but an error in the cartopy* package – when plotting vectors (such as e.g. currents from moorings) in a map using quiver, the vectors are wrongly transformed and end up pointing in the wrong direction… when googling the issue I quickly found solutions and workarounds (thank you StackOverflow!) but still… if I hadn’t tried to plot my scale vector at a 45degree angle I might never have found out…
After a bit of struggling in InDesign and with a lot of help from Ellen and google I’ve managed to put the Ninja story together into a book – which is now available online! So if you were wondering what to ask for in your letter to Santa… wonder no more!
Books are sold at “printing price” – no profit to me (but I presume amazon makes a cent or two).