The expedition Arctic Ocean 2025, blog post 5: We are alone now, it's colder and new ice is forming
Four weeks have now passed and there is less than two weeks left of our Arctic adventure. One can sense that people on board have started to realize this and react differently. Some refuse to think about it while others think about it all the time. This is human nature and the mood onboard is very good but it will be a special moment when we get back.
Everyone want to go home but we all also want to stay together. Since the last report, our expedition companion, the Canadian icebreaker Luis S. St. Laurent has left us. One morning a few days ago she turned left (or to port as we say) and disappeared in the fog.
One morning a few days ago she turned left (or to port as we say) and disappeared in the fog.
Not very far from the North Pole again, we have just stopped for an oceanography research station*, maybe the last one since we don't know when we'll get to stop again. We do have a fixed date when we need to be back in Longyearbyen. Work in the different work packages are so different. Some, like Meteorology, just keep going all the time. Others, like Sedimentology, need to stop the ship to be able to sample. Some can – if weather allows – fly out with the helicopter and come back with samples of ice, even as Oden continues along its track without stopping.
The group on "Primary Productivity & Biogeochemistry" has managed to combine both methods. They process lots of water samples from the CTD-measurements or from ice cores. But they also use water from the ships continuous ocean water intake about 8 meters below the surface.** Additionally they also conduct different experiments with (some of) their water samples that can run in between research stations. A lot of water has to be filtered to extract useful samples since concentrations of different species can be quite low.
The weather for most of the last week has been quite poor with a few storms passing. But one notable change occurred in the middle of last week, when summer ended and autumn started. It might seem strange that one can pinpoint the exact time, but that is often how it works in the central Arctic. The temperature suddenly dropped well below -2 degrees Celcius with the passing of a cold front and it hasn't really been up above -2 degrees since then. All precipitation since then has been as snow; no more rain.
But the most visible difference is that new sea ice is now forming in open water everywhere around us, even when the wind is high. But the sun was out for almost half a day in between banks of fog last week and did wonders for the mood onboard.
(Michael Tjernström, 8 September 2025)
*A “research station”
A “research station”can be either a location where the entire ship has stopped and various activities are taking place, or an ice floe to which a helicopter has flown. Its location can be significant, depending on the type of scientific work being carried out; for example, sediment samples are location-specific. Seawater can also be location-specific, but air is less so. The location may also be more random; what “research stations” have in common is that the work to be done requires a stable platform that does not move (especially much, because up here in the Arctic the ice moves, albeit quite slowly), so it cannot be done while the ship is moving.
**The water is drawn
The water is drawn from the hull 8 meters below, but comes out of a number of standard water taps inside the permanent main lab on the foredeck.
The icebreaker Oden has set sail and is heading for the Arctic to map the seabed. On board are 21 PhD students from various countries attending a research school where practical work is combined with lectures. Follow their journey in our blog, with weekly reports by Michael Tjernström, professor emeritus of meteorology at Stockholm University with extensive experience of Arctic expeditions, and responsible for the research school.
Blog and more articles about the expedition AO25
Last updated: September 8, 2025
Source: MISU