4 May 2023
Current position while writing (diamond shape). The circles are the positions at previous blog posts, the black line is roughly the route we took (base map from 
ggplot2).
While some parts of lab work are nearly exactly the same as in a lab on shore, other parts are completely different because the ship is a different environment. Safety equipment and storage of chemicals are the same as on land. Each lab, for example, has a list which of dangerous chemicals are stored where. And we even have clean labs on board.
Different from other labs and probably most similar to other mobile platforms, we have to bring our lab equipment with us. The ship only provides the basis (desks, sinks and power), everything else is brought by us and set up in just the way we need it for our individual research questions. And if you forgot to pack something, you have to find someone with it spare or find an alternative. There are no shops around to buy things..
With this, being creative and improvising solutions is part of the daily work. If something breaks, often the only way to make it work again to construct a fix from duct tape, cable ties, parafilm and whatever else is around to fix it.
After a while, the connection between the thick and thin tube began to leak so I had to repair it. This construction with a cable tie and parafilm has been working very well for a few days now. (Edit: I really shouldn’t have written this, it started leaking again and I had to replace the tube.)(Picture: Rieke Schäfer)
Empty bottles are very well suited as beakers.(Picture: Rieke Schäfer)
Everything has to be secured so it won’t slide or fall. Depending on what you want to secure this can be straightforward or a little bit more complicated. Additionally, you have to consider which things should not get wet and set them up at a safe distance from any potential water source. Saltwater is not really compatible with electronics and depending on what you do, there is a lot of water around that does not always stay in the place where it is supposed to stay (by the way, the paper from parafilm is much easier to remove after the roll got wet …).
Equipment, water and securing things are probably the most obvious things but there are also “smaller”, very crucial things to consider. One of these that you don’t need to think about too much on land is time. We are moving westwards all the time and every few days we change the time zone. If we note dates in the local time it would get very confusing very quickly. Therefore, we use UTC for all measurements. I also take my lab notes in UTC to make it easier to compare with the measurements later on. Another thing is that we can’t weigh things on board. The ship is moving and vibrating way too much to give any useful readings. This has potentially big implications for the measurements. For this reason, most measurement methods on ships rely on volumetric measurements with pipets or syringes.
Many other things are as on shore. Especially problems where you can’t explain what’s happening. Everything is working well and then suddenly something stops and you are sitting there wondering what went wrong. At mealtimes or during breaks, there are often discussions about what is not working again, especially with some people where the measurements are making new problems continuously.
On this cruise, we are very lucky that the ship is hardly rolling. Working under these conditions does not feel that different from working on land. However, if the ship is moving more an additional problem in the lab is that you have to move carefully and safely while the floor is tilted beneath you.
Sunset to relax after lab work (Picture: Rieke Schäfer)
Today, I also want to share some links that aren’t directly linked with the lab topic but might be of interest:
At https://www.oceanblogs.org/so298/ you can find the blog about this cruise from GEOMAR. There, individual research foci are presented by the groups on board themselves.
You can always check the current position of the "Sonne" at https://www.hamburg.de/fs-sonne-position/ – in case you are interested in where we currently are.
And if you want to explore the ocean and atmosphere a little bit with all their currents, temperatures and many more, I can recommend this online globe: https://earth.nullschool.net/. Currently, there is a current against us which you can see on the globe. One thing I find quite interesting is the stripe of “cooler” water (still between 27 and 28 °C) at the equator.
Screenshot from https://earth.nullschool.net/, where you can see the current and somewhat cooler stripe along the equator. The colour corresponds to temperatures with red = warm and purple = even warmer (check the website for a more detailed colour scale).
PTB doctoral student 
Rieke Schäfer is blogging here directly from the RV "Sonne" on her way west from South America across the Pacific Ocean.