Moviestar for a day?!

A while ago I was asked by the university (#realfaguib) if I wanted to present myself and my work in a short movie that they want to show to future students – and a few days later I found my office occupied by cameras of different sizes and three very nice journalists/moviemakers/photographers that came along. I quickly realized that making a short movie – I think they only want a minute or two – takes a loong time! Repeat, repeat, repeat – look into the camera, walk faster, walk slower, one more time, slower, shorter, clearer, louder, start over, look that way, look here, smile, don’t smile… at the end of the day, I was quite happy that I’m not a Hollywood movie star but an oceanographer in Bergen

 

Camera – and light – invasion of my office!
Kjersti and me doing our best to ignore the camera…

I think the movie will be released  shortly – but until then you can enjoy the nice article they wrote to go with it (in Norwegian)

We’re in Nature!

I remember vivid discussions with Anna over a loaf of freshly baked bread from our new bread machine. We were in the Southern ocean, somewhere in between New Zealand and the Getz Ice shelf in the Amundsen Sea on board the Korean icebreaker Araon and we talked about the moorings we were about to deploy, the proposal we have started writing, the experiments we wanted to run – but most of all we talked about what actually happens when ocean currents meet an ice shelf front. That was four years ago – and I’m super excited to see that a few days the results of those discussions (and a good deal of work on board Araon, on and around the rotating Coriolis platform in Grenoble and in numerous offices around the world) were published in Nature! Ice front blocking of ocean hear transport to an Antarctic ice shelf by A. Wåhlin, N. Steiger, E. Darelius, K. M. Assmann, M. S. Glessmer, H. K. Ha, L. Herraiz-Borreguero, C. Heuze, A. Jenkins, T.W. Kim, A. K. Mazur, J. Sommeria and S. Viboud – in Nature! (For those of you who are not into peer reviewed litterature and scientific publishing – this is probably scientific equivalent to an Olympic gold medal!)

So what did we find out – well, to make a long story short – we oceanographers talk about two types of currents. They are both driven by pressure gradients – but for what we call barotropic currents, the pressure gradient is caused by differences in sea level (i.e. in how much water there is) while for baroclinic currents, the pressure gradient is caused by differences in density (i.e. how heavy the water is).  The barotropic current is depth independent – this means that the current is equally strong from the surface down to the bottom, while the baroclinic current changes in strength (and potentially in direction) with depth. Our observations showed that the currents bringing heat towards the Getz ice shelf had both a barotropic and a baroclininc (bottom intensified) part. The barotropic part was the stronger one and the one carrying the majority of the heat. But when the current reached the ice shelf front (Anna was brave enough to deploy a mooring only 700m from the ice shelf front)  – the strong barotropic current had to turn, and only the weaker baroclinic current was able to enter the ice shelf cavity. The experiments at the rotating table showed the same thing – barotropic currents turned at the front, while baroclinic currents could enter.

Experiments at the Coriolis platform in Grenoble – a 13 – m large combination of a swimming pool and a merry-go-round!

You can read more about what we did in the Coriolis lab here, and about when Karen recovered the moorings here

#BergenWaveWatching: Rainbows!

Kjersti, Steffi, Elin and myself (Mirjam) recently discussed ways to better integrate the GEOF105 student cruise into the course. My suggestion was to ask the students to observe things throughout the whole duration of the course, and then have them relate their time series with what they observe when “at sea”. In this mini series tagged #BergenWaveWatching, I write up a couple of suggestions I have for observations that are easy and fun to make. I am anticipating that my suggestions will be strongly biased towards #wavewatching, so if you have any other suggestions, I am all ears! 🙂

Neither wave watching nor particularly Bergen-specific, but still super cool! And probably as close as I will ever come to suggesting any kind of meteorological observation. Clouds are pretty amazing, too, but I really don’t know enough about those…

Where to go

Nowhere specific, just keep an eye out for situations in which there are water droplets in the air and the sun is low enough in the sky for rainbows to appear. Be aware of where rainbows would appear if they were visible (the shadow of your head would be in the center of the rainbow) and check out if they are there.

It doesn’t actually have to rain for rainbows to appear…

When to go

Since the sun needs to be sufficiently low in the sky for rainbows to be above the ground, rainbows are more likely to appear in the morning and afternoon.

What to look out for

Duh. Rainbows?

What to do with the data

I think it could be fun to try and relate the appearance of rainbows to the kind of weather. Obviously, you need both sun and rain. But for double rainbows, you need several rain fronts behind each other. And for a secondary rainbow as in the picture on the very top (blog post on that here), you need strong sunshine.

The observations suggested here are also well suited for a description of the phenomenon and an explanation of the physics behind it.

How this is relevant for the student cruise

Not directly, but I think getting into the habit of observing something fairly specific and, over time, becoming an expert on spotting and explaining rainbows, is pretty awesome!

Do you have suggestions for us? What other spots or topics would you recommend in and around Bergen to be added to the #BergenWaveWatching list? Please leave a comment! We are always looking to expand this list!

COSMUS – a multidisciplinary expedition to the Weddell Sea in 2021

Today I’ve been listening in on the COSMUS cruise-planning meeting at AWI in Bremerhafen – it’s been great to hear all the groups that are joining the cruise tell about the exciting research that they are planning! During 75 days  – no that’s not a typo, 75 days or almost eleven weeks* – at sea, physical oceanographers, sea-ice physicists, all sorts of biologists and bio-geo-chemists will live and work onboard Polarstern – and people will do so many cool things! There will be bottom landers that measures the oxygen consumption of benthic fauna, bottom crawlers that map the ocean floor at millimeter precision, microplastic filtering, profiling with high cameras to quantify the amount of sinking organic matter… and off course plenty of good old CTDs and moorings! There will also be seal tagging, and I was excited to see my name in the group of people that gets to go on the ice and actually meet the beasts up close!

I joined Polarstern on a cruise in 2005, when I’d just started on my PhD. I bet many things will have changed – but rumours has it that “Zillertal” (the small bar) is still around!

Joining Polarstern in Cape Town for my first Antarctic cruise in 2004. In 2021 I’ll do it once again.

*I didn’t tell my husband yet that the cruise will be that long, not quite sure about how to break the news… I’ve been told to tell things like that when there are lots of people around – and preferably nice food on the table… but I’m not sure about that one!

All moorings are onboard!

Congratulations to @MarkusMelin4 and @cisprague who has recovered four out of four moorings in the Amundsen Sea! Despite fishing vessel rescue-operations, iceberg-on-top-of-mooring-problems and strong winds the four moorings and all of the instrumentation are now safely on deck! One of the top boys had suffered from an iceberg encounter and the connector plug on my ADCP (A large instrument that measures the current velocity in the water column using acoustics and Doppler theory) had been leaking…. but that’s just little scratches when you consider that they’ve spent two years in the water!

I look forward to see what the records has to tell us about the currents and the hydrography around the Getz ice shelf. Stay tuned!

Uff – seawater can do horrible things to instruments. Luckily it can be repaired! Photo: Markus Melin

 

#BergenWaveWatching: On vibrating surfaces

Kjersti, Steffi, Elin and myself (Mirjam) recently discussed ways to better integrate the GEOF105 student cruise into the course. My suggestion was to ask the students to observe things throughout the whole duration of the course, and then have them relate their time series with what they observe when “at sea”. In this mini series tagged #BergenWaveWatching, I write up a couple of suggestions I have for observations that are easy and fun to make. I am anticipating that my suggestions will be strongly biased towards #wavewatching, so if you have any other suggestions, I am all ears! 🙂

Where to go

We spotted standing waves in a bucket on the latest GEOF105 student cruise, but in addition to on ships, they can also be spotted for example on trains (see pic below), in cars, or even on washing machines.

What to look out for

The pattern that form on the surface of vibrating fluids

What to do with the data

Describe the pattern and try to understand why it looks the way it does (like I did here). Is it the frequency of vibration? The shape of the vessel? The material of the vessel? The location relative to the source of vibration?

Do you have suggestions for us? What other spots or topics would you recommend in and around Bergen to be added to the #BergenWaveWatching list? Please leave a comment! We are always looking to expand this list!

Today is #CTDappreciationDay !

CTD – which is short for Conductivity-Temperature-Depth  – is indeed a much appreciated instrument by every (sea-going) oceanographer. You send it down to the bottom of the ocean, and back comes nice profiles of temperature, conductivity (from which one can calculate salinty) – and whatever other sensor you’ve attached (oxygen, chlorophyll, and turbidity for example)

The CTD in its rosette on its way down into cold  Antarctic water on a Polarstern cruise.

Most of the time the CTD is mounted on a rosette, which carries bottles so that one can also collect water samples from selected depths. But make sure to have the bottles open when you send them down – otherwise they will implode, and that is not a good thing, believe me!

Filling bottles with water at the freezingpoint (-1.9C) is a cold job!

#BergenWaveWatching: “Remote sensing”

Kjersti, Steffi, Elin and myself (Mirjam) recently discussed ways to better integrate the GEOF105 student cruise into the course. My suggestion was to ask the students to observe things throughout the whole duration of the course, and then have them relate their time series with what they observe when “at sea”. In this mini series tagged #BergenWaveWatching, I write up a couple of suggestions I have for observations that are easy and fun to make. I am anticipating that my suggestions will be strongly biased towards #wavewatching, so if you have any other suggestions, I am all ears! 🙂

Where to go

Anywhere where you can look out over water, for example Fjellveien (where the picture above was taken from) or Fløyen

When to go

Any time

What to look out for

Pattern on the water. Can you see wakes? Langmuir circulation? Gusts of wind? Areas that are sheltered from the wind?

Langmuir circulation in Østerfjorden, described here.

What to do with the data

Observe closely and try to make sense of it by relating it to, for example, ships, weather at that time, …

Do you have suggestions for us? What other spots or topics would you recommend in and around Bergen to be added to the #BergenWaveWatching list? Please leave a comment! We are always looking to expand this list!

#BergenWaveWatching: Bergen Harbour

Kjersti, Steffi, Elin and myself (Mirjam) recently discussed ways to better integrate the GEOF105 student cruise into the course. My suggestion was to ask the students to observe things throughout the whole duration of the course, and then have them relate their time series with what they observe when “at sea”. In this mini series tagged #BergenWaveWatching, I write up a couple of suggestions I have for observations that are easy and fun to make. I am anticipating that my suggestions will be strongly biased towards #wavewatching, so if you have any other suggestions, I am all ears! 🙂

Where to go

Bergen Harbour

When to go

Any time you might have to run errands around there anyway

What to look out for

So many things! Here are a couple of examples:

  • Waves. What direction are they coming from? What causes them?
  • Wakes, as a special form of waves. Which ship/animal did they originate from?
  • Reflections of waves on the straight walls of the harbour basin (like I did here)
  • Tides
  • Water levels in general

What to do with the data

Describe and try to make sense of it by relating it to other variables like wind speed and direction, atmospheric pressure, tides, shape of the boundaries, ships, etc, like I did for example here.

Do you have suggestions for us? What other spots or topics would you recommend in and around Bergen to be added to the #BergenWaveWatching list? Please leave a comment! We are always looking to expand this list!