Finally in Antarctica! Science has started

Vår reports from Antarctica:

Cruise work is hard work! A week ago the actual scientific part of our cruise started, and we’ve been on our feet since. We deployed the Sail buoy and Sea glider just north of the sea ice edge and then headed into the ice. The “ice edge” is really a fitting term: you’re in open water, and suddenly, there’s ice all around. This depends on the wind and tides, but when we passed south it was a perfectly clear boundary, and very nicely marked the arrival of our science week. As soon as we passed into the ice penguins started to pop up, and we were all running back and forth on the bridge trying to spot them all. There are mostly Adelie penguins here, but we’ve spotted a few emperors as well, a few seals, one group of orcas, and another group of whales that we think might have been Minke whales.

The sea ice conditions were a bit harsher than we’d hoped for and we had to change our route a bit, but it looks like we will cover most of the planned CTD stations and our mooring locations by the end. In addition, we got some measurements from a polynya just east of our ice shelf destination due to the detour we had to take.

On the ice shelf. Suddenly the ship is not so large anymore. Photo: Vår Dundas

On New Year’s Eve, we reached the ice shelf, and the crew anchored the ship to the ice front. To put it in perspective, we had to walk to the 9th floor to be on the level with the ice shelf. The crew from the Troll station arrived just before us and had already set up camp – it was a surrealistic sight to suddenly see people and “civilization” so far from anywhere, and after so many weeks without meeting any new people! As soon as the anchors were in place the unloading began, and we started an intense MSS profile protocol on the other side of the ship. As I’m most used to working with profiles from the other side of Antarctica and by far this close to an ice shelf, these profiles looked like nothing I’ve seen before. The software lets us look at the profiles real-time, and as we always do this profiling in pairs it’s been really interesting to discuss what might be happening in the ocean below us while taking the measurements. I’m growing very fond of this MSS instrument!

We our first day in 2021 on the sea ice itself. In Rektangelbukta, there is fast ice – sea ice that is attached to the coast – which makes it relatively stable and safe, and perfect for sea ice measurements. We packed our instruments and our lunch and set off on snow scooters with one of the guys from Troll who had assessed the safety some days before. As we arrived at our spot, we were welcomed by a team of very curious Adelie penguins and a serious-looking emperor penguin.

Photogenic Adelie penguins that paid us a visit. Photo: Vår Dundas

They lost interest in us when we were done with our lunch and started the process of digging a perfectly square pit in the snow to reach down to the ice. Our main task on the ice was to take ice cores to study temperature, salinity, biology, microplastics, and more, and to get these cores, the snow must be removed first.

Science is hard work! Photo: Vår Dundas

When we pulled up our first core, the ocean flooded up through the hole, and suddenly our nice solid area was a shallow swimming pool. This happened because there is so much snow that it pushes the snow-ice interface below sea level. After pulling up all our ice cores we made a hole large enough to drop instruments through and got measurements of both temperature, salinity, some helium samples, turbulence, and also a special kind of ice called platelet ice, which forms in the ocean itself, not at the surface like normal sea ice. It was an extremely long day, and my face was burning and my eyes stinging when we got back to the ship from all the reflection in the snow, but also such a great day with lots of sampling methods I’ve never done before, the creativity of setup, and of course penguins and coffee breaks with the Antarctic sea ice and distant icebergs as the view. And I’ve done a cartwheel on Antarctica!

Mooring deployment. The buoy contains an Acoustic Doppler Current Profiler, which measures ocean currents.  Photo: Vår Dundas

Now, we’re heading northward, and we’ve only got a few days left of scientific work. So far, the moorings have been deployed and recovered successfully, and hopefully, I’ll be able to say the same about the last mooring in just a few days. We continue with CTD stations and MSS profiles, water sampling, and mooring preparations. When all of this is done we’ll hopefully have time to do some bird and whale observations on our way back to Cape Town, besides packing up all our gear and tidying up the containers. On the way south we saw new species every day, and it would be interesting to see whether we see the same pattern on the way back. But for now, we focus on the work for the next few days and try to avoid any major problems.

A few minutes of well-needed rest! Photo: Tore Hattermann






The seaglider is about to be deployed. If all goes according to the plan it will be recovered by Polarstern (with Elin onboard) later this season. Photo: Vår Dundas


Crossing the equator

Vår Dundas reports from Malik Arctica:

We’re in the southern hemisphere! The last, almost two, weeks have flown by, filled by a mix of deck work and what I guess you could call home-office. We survived the Bay of Biscay without too many scratches – mostly everything was well secured in our container. Not being used to life at sea and the importance of securing every tiniest thing, I had a very annoying bottle of detergent rolling around on my bathroom floor throughout the night, and a small glass bottle decided to jump out of the cabinet, making a total mess that I had the pleasure to clean up. Otherwise, we were mostly unharmed.

Our ship from above. Photo: Christian Harbor-Hansen

Last Monday, summer began for us, and we’ve been working on deck in shorts and t-shirts until today. Thirty degrees in both air and water is something you get used to quickly, especially in December. What a luxury! Our main task has been to continue testing our equipment. Every instrument must be set up to talk with their respective computers and software, which is often more complicated than it sounds. Through long processes of try and error, we have installed drivers, detected COM-ports, and switched cables and batteries. Now we finally think we have all programs in order, and we’re able to communicate smoothly with all our instruments.

Julius and I are out on deck working with instruments for measuring
helium below the sea ice, and Kristen is reading instrument mauals. The
two blue containers to the left are the CTD and winch containers, the
white one is Kristen’s engineer lab, the middle blue is Sebastiens
bio-lab, and the right one is where we’ll be taking water samples and
where the portable winch is. Photo: Tore Hattermann.

Since we don’t know how conditions will be at the ice shelf front, we’re bringing several setups for measuring conductivity (which we translate into salinity) and temperature (our CTDs). If everything is smooth and calm, we have a large one to use, which we prefer. It is can take water samples at several depths, and measure both temperature, conductivity, fluorescence, oxygen, and incident light. However, this CTD is dependent on the cranes on the ship, and in bad weather, these will be difficult to maneuver safely. So we are bringing a small one as well, which we can operate with a much smaller portable winch. In addition, we have an even smaller one, which we can also bring out on the sea ice itself to drop down below the ice through a borehole. Many options mean many things to test, but after today’s final tests, I think we might be good to go regarding winch systems and CTD-setup. It’s good to be getting things in order!

The testing of the MSS attracted an audience! Here we are, all looking
for it to resurface. Photo: Christian Harbor-Hansen



We have also managed to wake up the autonomous Seaglider from Norgliders and the Sailbuoy from Akvaplan-Niva which we have onboard, and made them talk with their respective owners at GFI in Bergen and at Akvaplan-Niva. We have labeled countless sampling bottles and practiced water sampling routines for nutrients, helium, CO2, oxygen, and a few more. The captain was met with great excitement when he spontaneously decided to take a short stop in the middle of the ocean so that we could do a proper profile with the MSS to finally check that we had everything in order and to practice the profiling procedure.

Life onboard is, however, not all about testing equipment. We saw a blue whale just north of Madeira (we think), which I’m still very excited about, a few dolphins, and a whole bunch of flying fish (they get so far!). And there are more creatures in the ocean – if you try to cross the equator without being baptized, King Neptune knows, and he comes on board. No one may cross the equator without being baptized. So we were baptized, and are now part of the Trusty Shellbacks and initiated into the Solemn mysteries of the ancient order of the deep, after drinking a horribly tasting cleansing potion that I suspect is mostly based on fish oil, smeared in another sticky potion, and finally completely drenched in seawater. Besides this slightly traumatizing baptism, I’m delighted to have been renamed (you get a new name when entering King Neptune’s ranks) the Psychedelic frogfish, as they are amazingly cool (give them a search). To celebrate our new worthiness at sea, we had a soccer tournament in the cargo hulls. I wish I had a picture, but the match was too serious to have the time for photos.

Our baptism. King Neptune is paying close attention to the rituals in
the lower right corner.


As soon as we crossed the equator, the weather turned colder and cloudier, giving our sunburns some well deserved time to heal. Still, I hope we get a bit more summer-warmth before entering the cold and icy Southern Ocean. If things go according to plan, we will reach Cape Town around the 20th of December, where we’ll bunker up on fuel before starting our final transect towards the ice shelf.

As far as I’ve understood, until recently Danish law required every ship
to have some kind of a pool. And what better time to use it after
working a long day on deck in 30 degrees? Photo: Vår Dundas


Warm weather – but too much ice?!

Vår, Malik Arctica, and the others from NPI are steadily heading south and have just passed Madeira.  Temperatures are rising  – and so is the interest in the Weddell Sea ice concentrations. Currently, there is way too much red (high concentrations) in the map (below), but a lot can happen in the three weeks that are left of their journey… fingers crossed for a big storm that clears the area where they are to work!

Sea ice concentration in the eastern Weddell Sea (Red = dense ice, Blue = open water). White circles (DML1-2 & DML2-1) are the moorings that are to be recovered. (Credit: Roberto Saldo,, DTU Space and Technical University of Denmark)

Vår & Sebastien enjoying the sun. (Photo: T. Hattermann)






Out of isolation!

Vår Dundas writes about her first days on board Malik Arctica:

The two weeks of isolation and quarantine are over, and we are on our way southward! It feels good to be moving and getting closer to Antarctica. The first week at the hotel was a challenge – staying indoors on a few square meters with food delivered at the door by people in face masks who run away down the hallway as soon as you open the door is not a dream scenario. But miraculously, with a long parade of Teams meetings, a pile of work, workout challenges, yoga, and long facetime calls, the week passed by faster than expected. We all came out on the other side, mostly unharmed, but for a corona test in the nose, which made us all cry. Soon, we found ourselves at the harbor, next to our home for the next seven weeks, Malik Arctica: a massive (at least in my eyes), red container ship, with a white tower at the end, our living quarters.

Malik Arctica – my home for the next seven weeks (Photo: T. Hattermann)

As mentioned in my previous post, the science deck had to be built as this is not a research ship, and this is what we spent much of the onboard quarantine-week doing. Our containers came on board one after the other, and we started lifting and moving and removing all the (quite heavy) boxes to get everything organized and set-up. I got a very pleasant surprise when opening my box to find a Christmas gift from my supervisors! We now have six containers in all: one for mooring and CTD-winches (to lower and pull in cable), an engineer-lab, a bio-lab, a CTD-lab, and two storage containers for instruments and equipment. It is looking quite good now! Let’s hope the bad weather we’re heading through now doesn’t reorganize everything…

Another large part of last week went to getting used to the MSS instrument. MSS is a microstructure probe and is used to measure turbulence in the ocean. Turbulence is very high frequency and small scale motion, which makes it hard to measure. The instrument must be free-falling through the water to eliminate movement, such as drag on the cable. Even so, small movement as vibrations from the ship through the cable might disturb the data the instrument records. We, therefore, need to practice before taking real measurements at the ice shelf front, which is one of our goals.

Julius Lauber and Tore Hattermann deeply concentrated over the MSS-setup. (Photo: V. Dundas)

Today we are passing the Bay of Biscay, and the weather is accordingly bad. We are all crossing our fingers that the seasickness won’t be too bad, and so far, we’re doing good. Apparently, the wind will increase later today, so let’s see how we cope… Yesterday we passed through the English channel in clear weather and saw both France and the Cliffs of Dover. And soon, we will be entering warmer waters and approaching summer again. I’m quite excited about some warm weather and sunny skies.

Calm seas in the English Channel before heading into bad weather in the Bay of Biscay. (Photo: V. Dundas)


We’ll just have to make it through this small storm first.


We’ve also met the crew and gotten used to the ship. It is relatively new, has nice cabins (we don’t even have to share), good food, a gym, and a common room for watching movies and playing games (I think we all might be decent Mario Cart players by the end of the cruise). The stewardess has even already started decorating for Christmas, and they’re screening a Danish “julekalender” in the evenings. The other day we got a tour of the engine rooms and cargo hull – it is absolutely impressive. The engine room is a labyrinth of stairs and half-stories, seemingly going on forever, and the cargo hulls are immense. Most of the cargo we are carrying is on deck, and the ship is just taking 100 of 600 possible containers, so the hulls are huge and relatively empty, making for an impressive sight.


This is our group: Me, Sebastien Moreau, Tore Hattermann, Kristen Fossan and Julius Lauber.
(Photo: Christian Harbor-Hansen)

Antarctica day!

December first is not only the day when you are supposed to change the batteries in the fire alarms (did you?) – it is also Antarctica day! To celebrate that I asked Nadine and Kjersti to send me their favorite photos from Antarctica – so please enjoy!

Nadine’s favorite #1:  A Southern Giant-petrel sails over pancake ice while the sun sets over Dronning Maud Land (Photo: N. Steiger)
Nadine’s favorite #2: This beautiful anemone was captured by the camera of an ROV (remotely operated vehicle) at the floor of the Southern Ocean at several thousand meter depth during my cruise to the Dronning Maud Land in 2019 (Photo: ROV Ægir6000, processed by Rudi Caeyers)


Kjersti’s favorite: Socially distanced penguins on the only Corona-free continent (Photo: K. Daae)


I managed to get my favorite icebergs down to these two…

                                                                                                                                                                        Photo: E. Darelius                                                                                                                                                                         Photo: E. Darelius

… but it was just impossible to chose between the penguins – so here’s a bunch of them!

                                                                                                                                                                        Photo: E. Darelius

                                                                                                                                                                        Photo: E. Darelius

                                                                                                                                                                        Photo: E. Darelius

                                                                                                                                                                        Photo: E. Darelius

                                                                                                                                                                        Photo: E. Darelius

                                                                                                                                                                         Photo: E. Darelius

                                                                                                                                                                        Photo: E. Darelius

                                                                                                                                                                        Photo: E. Darelius


                                                                                                                                                                        Photo: E. Darelius

… just had to add this one to show that they are not always cute!


Looking for some easy ocean experiments? You just found them!

Today is the first day of my (Mirjam’s) “24 days of #KitchenOceanography” advent calendar. This year not only in English and German, but also in Norwegian and Portuguese!

A huge thanks to Jacob for his amazing work translating & prettifying & adding to & posting the calendar on GFI’s web pages & social media (Facebook, Instagram and Twitter)!

My students report: Rossby waves in a tank

I asked my students to write a “blog version” of the lab report they had to hand in as part of the course in geophysical fluid dynamics that I’m teaching this semester – below is one of them!

Planetary Rossby Waves (Written by Sigrid Vildskog & Guillaume Bonduelle)

When most people think about waves, they probably think of ocean waves crashing into the shoreline and beaches, but waves are so much more than that! In this report we are going to look at planetary Rossby waves, and how we can simulate them in the classroom.

First; what is a Rossby wave? Rossby waves are slow-moving large-scale waves that occur in rotating fluids, such as both the atmosphere and ocean. They are always propagating towards the west, due to something called vorticity and the change in the Coriolis force with latitude. The vorticity makes the fluid turn clockwise (or anti-clockwise) if it is displaced northward (or southward).

Second; what is Coriolis? Coriolis is the force that occurs when we are in a rotating system.  Large-scale movement on the earth is affected by the rotation of the earth. The effect of the rotation is dependent on latitude; there is no Coriolis force at the equator, and it increases towards the poles (negative values in the southern hemisphere).

Third: How do we simulate this change in latitude in the laboratory? In the laboratory, we use rotating tables, but the rotation rate of the table (and therefore the Coriolis force) is constant, so it’s impossible to simulate any kind of latitude. Lucky for us, there are two kinds of Rossby waves: one that is dependent on changes in latitude, and one that’s dependent on changes in depth. If we look at the equation describing vorticity, we see that changes in the Coriolis parameter (i.e. latitude), and changes in depth have the same effect on the vorticity. Therefore, in our experiment, we can use a tank with a slanted bottom to simulate the planetary Rossby waves.

Ice cube in the north-east corner at the start of the experiment (Photo: Sigrid Vildskog)
Ice cube in the north-western corner at the end of the experiment. The blue “swirls” are formed by the Rossby wave! (Photo: Sigrid Vildskog)

Our rotating table is rotating anti-clockwise, so the shallow end of the tank is “north”. We placed a dyed ice cube in the north-east corner of the tank. The cold and heavy colored water from the melting ice cube sank towards the bottom and drained down the slope of the bottom of the tank. This movement induces stretching of the colored water column, and it will start to rotate. The rotation sets up a wave, that propagates westward in the tank. The ice cube itself moves to the western side of the tank with the wave!

This experiment allowed us to see the similarities between Rossby waves and Topographic waves with our own eyes, and experience that oceanographers can simulate a large scale system with simple equipment in a small laboratory.

Full panic. Again.

– Are you sitting down? Anna is on the phone from Gothenburg.

– Yes? Why? The potential-catastrophic-scenarios-creating-center (pCCCC) of mine is normally working hard 24/7, but this time it was caught completely off guard…

– I just got a phone call from a truck driver on his way to deliver scientific instrumentation to me from Germany; and the only instrumentation I have in Germany is the one that is supposed to go with you on Polarstern.

You might remember that we had major trouble getting Anna’s instrumentation (that I’m to deploy in the Weddell sea this winter) through customs in Germany (if not, read about it here). Well, despite all our efforts (and prayers) and German documents we failed. To get the instrumentation onto Polarstern we would have to send everything back to Sweden and start over, we were told… and then we would have missed the deadline. Luckily Hartmut (the cruise leader) entered the scene and saved the situation by kindly “adopting” our packages onto his freight lists (don’t tell anyone!) and the problem that seemed impossible to solve was suddenly solved.

But now it seemed like Anna’s boxes had been returned to Sweden after all? What had gone wrong? What should we do? Would there be time enough to do anything? When was Polarstern leaving?

Anna’s desperate attempts to get the truck driver to turn around and return to AWI and Germany obviously didn’t work out…

At AWI they claimed that Anna’s boxes were still there. Maybe some of the boxes that had been unloaded from Mosaic had been sent to her by mistake?

My pCCCC wasn’t fully satisfied with that explanation… but that’s likely what had happened. Puh!

– or like a friend of mine used to say: “Another good worry wasted!”


Necessary conditions for warm inflow towards the Filchner-Ronne Ice Shelf

Kjersti Daae in her model domain!

For quite some time now, Kjersti (et al) has been working hard to set up a regional, high-resolution model of the southern Weddell Sea  – and yesterday the results from all her work were finally published in GRL!

Below Kjersti summarizes her work:



Modeled melt rates below the Filchner-Ronne Ice Shelf. Only when we applied extreme changes to the forcing did the melt rate increase. From Daae et al., (2020) available at

The Filchner-Ronne Ice shelf comprises 450 000 km2 and is the world’s largest ice shelf by volume. In contrast to the rapidly increasing melt rates in the Amundsen Sea, the Filchner Ronne melt rates are low, and a cold-shelf-regime dominates in the Weddell Sea. Warm water of open-ocean origin has limited access to the shelf and the cavity beneath the Filchner-Ronne Ice Shelf. But how could this system change in the future? Could global warming lead to a regime shift from cold-to-warm in the Weddell Sea?

We have studied the Weddell Sea system using a regional ocean model with idealized forcing to learn more about the processes that control warm water flow onto the continental shelf and further into the Filchner-Ronne Ice Shelf cavity. Two main factors currently prevent warm water from accessing the Weddell Sea continental shelf. Firstly, the warm water is located deeper than the continental shelf and does not have direct access. Secondly, the Weddell Sea continental shelf is filled with dense water masses that block an inflow of warmer and lighter water. We find that the Weddell Sea system is robust, and we need to make extreme changes to both factors to allow warm water access to the continental shelf.