Meet our PhD student Johannes Lohse

Johannes Lohse (29) started his PhD in CIRFA WP2 in January 2016, and will spend the next four years doing research on sea ice classification using SAR.

Johannes, where do you come from, and what is your educational background?

I come from northern Germany. I studied Geophysics at the University of Hamburg and spent one year in Longyearbyen at UNIS, specialising in polar geophysics. Ever since my stay on Svalbard I have been hooked on everything related to polar research. For my Master thesis I conducted a measurement campaign on Ekstrømisen, Antarctica, acquiring ice thickness data and investigating the influence of tidal motion on the flow velocity of the ice shelf. After finishing my Master’s I returned to Antarctica and wintered at the German research base “Neumayer III”, operating the geophysical observatory for 14 months.

Why did you choose UiT/CIRFA for your PhD studies?

I wanted to conduct a PhD study in a sea ice-related topic and UiT/CIRFA offered a perfect opportunity to do this. I find it a lot easier to focus on the work when I am living in an area or environment that is actually linked to the theme I am working on. So in some ways I would say doing research on sea ice is a lot easier for me here in Tromsø than it would be in Germany.

Furthermore, I think that the scientific education differs between universities and I therefore liked the idea to do my PhD somewhere other than where I did my Master. I feel that in this way I can learn a lot of new things and I hope I can also bring new aspects and ideas into the Earth Observation group here at UiT.

Could you please briefly describe your project?

In my PhD project I am working on sea ice classification from SAR data. First I will focus on fully polarimetric SAR data, using polarimetric features to test and improve existing algorithms or develop new strategies for sea ice segmentation and classification. While segmentation in this case implies clustering pixels with similar statistical properties of polarimetric features, classification requires labelling these segments with respect to their ice type. The classification therefore requires an understanding of the relation between features and ice types.

Later stages of my project will involve tests of classification algorithms under varying acquisition conditions of the SAR data (e.g. changing incidence angles or different frequencies) and to go from fully polarimetric to dual-polarised data or compact polarimetry in order to get larger spatial coverage on the ground.

What benefits do you expect from this work for your professional development?

In the first place, I hope that working on this project will give me a chance to improve my knowledge and understanding of sea ice physics in general. With a more pronounced background in solid earth geophysics and a lot of previous fieldwork experience, I am also looking forward to improving my skills in statistical methods and to working with remote sensing in order to obtain expertise in these fields.

Photos: Johannes Lohse