Trial lecture and defense - Master in industrial engineering Bernhard Schartmüller

Later, at 12.15 he will defend his thesis entitled:

«Characterization, calibration and optical performance of ocean light instruments and the legal background for deployment in the Arctic»

Deputy leader at Department of Arctic and Marine Biology, Professor Monica Alterskjær Sundset will lead the disputation.

Popular Science Summary:
While commercial light instruments can measure high and medium light intensities, there are few that can capture the low light conditions, consisting of light from moon, stars and aurora, that prevail during the (polar) night. In the ocean, light intensities are even lower because of the high absorption of water, optically significant constituents and phytoplankton. In polar regions, snow and sea ice can reduce the light in the ocean even further to a fraction of the light intensities at the surface. Still, even these low light intensities are sufficient to act as a cue for biological processes e.g. diel vertical migration of zooplankton. This illustrates the need for sensitive light instruments. However, for measurements to be useful these need to be of sufficient quality. The focus of this thesis is the development of characterization and calibration methods for two ocean light instruments. The first one, the Optical Chain and Logger (OptiCAL) is an autonomous ice-tethered observatory consisting of a buoy and a cable that can host up to 32 light instruments, providing depth resolved light measurements. The second one is a commercial underwater hyperspectral imaging (UHI) instrument that can provide angle-resolved radiance measurements and hyperspectral images. To maximize the range of potential users, the developed calibration methods use simple setups that have potential to be replicated at many institutions. In addition, the interdisciplinary part of this thesis discusses three different platforms for collecting scientific data in the marine arctic and the applicable legal framework, which is a prerequisite for carrying out the research. This is especially relevant in times of increasing autonomous data collection.

Evaluation Committee:

• Professor Oliver Zielinski, the University of Rostock, Germany (1. opponent)
• Professor Fred Sigernes, UNIS, Svalbard (2. opponent)
• Associate professor Karley Campbell, AMB (internal member and leader of the committee)

Supervisors:

• Pro-rector for research at UiT, professor Jørgen Berge
• Professor Geir Johnsen, Department of Biology, NTNU

Streaming:

Both defense and trial lecture will be streamed from store auditorium E-101 at NFH:

• Trial lecture
• Disputation

Thesis:

The thesis is available through Munin