Dr Christian Katlein
Sea-ice Physicist at the AWI
Even before he began working at the AWI, as a tourist guide Christian was always drawn to Spitsbergen’s natural beauty. Back then he was still studying Astrophysics and Geophysics at the University of Tübingen before, after a semester abroad in Spitsbergen (in 2011) and a few happy coincidences, he found himself writing his diploma thesis at the AWI. He then completed his thesis during his first expedition on board RV Polarstern, which took the entire summer, an experience that led him to specialise in sea ice. After three years working on his doctoral dissertation, a postdoc position at the AWI and an eight-month-long research exchange to Canada, he returned to Germany just in time for the MOSAiC expedition.
His research interests chiefly concern the optical qualities of sea ice, like its transparency. Accordingly, his findings are especially important for marine biology, in terms of analysing the growth of microorganisms or investigating how microplastic influences marine ecosystems. In this regard, he also works on the development of measuring technologies like Remotely Operated Vehicles (ROVs) and autonomous buoys. In order to continually refine these technologies, he enjoys adding various components by hand; a type of work in which his past experience as a lighting technician in his high school’s theatre group has proven to be unexpectedly helpful.
Moreover, his involvement with the topic of sea ice often extends beyond his day-to-day work. Not only does he actively take part in conferences and continue to work as a tourist guide in the Arctic; he also regularly gives talks at schools, and shares his expertise in videos ranging from impressive to humorous on his YouTube channel “Sea Ice Stories” (https://www.youtube.com/channel/UC8EP9eISDO8IHYrKfXuLizg). He’s also investigating ways to use more affordable materials in marine research, and to make technological advances publicly available via open source hardware.
What was the first expedition that you took part in?
In 2011 we went to the North Pole with RV Polarstern and took the AWI’s first-ever ROV-based readings below the ice. I also wrote my diploma thesis on this work. In the beginning, we all still had plenty to learn, and simply rented an ROV for the task. A few years later, we knew what we needed, and thanks to the FRAM project in 2016 (https://www.awi.de/en/expedition/observatories/ocean-fram.html) we finally got an ROV of our own. FRAM (Frontiers in Arctic Marine Monitoring) was essentially an infrastructure project focusing on the establishment of long-term observatories in the Arctic. In the project, I was explicitly responsible for spearheading the development of the ROV.
What have been the most important findings in your research career to date?
While working on my doctoral dissertation, I realised that light scattering in sea ice didn’t work the way that most models assumed it did. To put it simply, it makes a difference whether you look through the ice from above or below, and from the right or the left. These varying optical qualities are due to the structure of the ice. We used to assume that the light field below the ice was isotropic (direction-independent), in other words, that the light was equally intense in all directions. But due to the unique nature of light scattering in sea ice, that’s simply not true, so when you assume the light is isotropic, it can produce errors in calculations and models.
How do you contribute to meereisportal.de, and who do you particularly want to reach with your research?
I work quite a bit with buoy data, and am constantly writing new software. Part of my work at meereisportal.de involves helping with the ‘go-live’ for this data on the data portal. Once the data is live, it makes my job, and that of others in my working group, much easier, since we can all quickly and easily access the data we need. But I’ve also used this feature while giving talks at schools; I can quickly check meereisportal.de to find out what the sea-ice temperature in the Arctic was on the day before. Being able to access information from the Arctic in real-time is a real advantage, plus I feel it’s important that anyone interested in this information also has access to it.
My personal hero is …
Finn Malmgren. He was a Swedish meteorologist and the founder of sea-ice physics. I find it fascinating that, for his doctoral dissertation, he overwintered in the Arctic for three years nonstop.