New ARCTOS PhD: Ingrid Wiedmann

This autumn another ARCTOS PhD student successfully defended her thesis: Ingrid Wiedmann. Friday November 13th could not scare her nor the many colleagues, friends and family members who attended her trial lecture and defense of her thesis entitled:

“Potential drivers of the downward carbon and particle flux in Arctic marine ecosystems under contrasting hydrographical and ecological situations”

Photos taken by Ellen Katrin Bludd

In order to investigate potential drivers of vertical POC flux Ingrid deployed short-term sediment traps under contrasting hydrographical and ecological situations in the Barents Sea (north-south gradient study) and in Adventfjorden, Svalbard (seasonal study). In the Barents Sea the highest POC flux was observed in the south (post-bloom situation) and in Adventfjorden during autumn. Ingrid’s study also shows that high vertical POC flux is not necessarily caused by large sinking particles or a high sinking particle volume, but may also occur in form of small particles with a high POC:volume ratio.

Ingrid’s thesis consists of three articles:

  • Paper I Wiedmann I, Reigstad M, Sundfjord A, Basedow S (2014) Potential drivers of sinking particle’s size spectra and vertical flux of particulate organic carbon (POC): Turbulence, phytoplankton, and zooplankton. Journal of Geophysical Research: Oceans 119: 6900-6917. doi: 10.1002/2013JC009754
  • Paper II Wiedmann I, Tremblay JE, Sundfjord A, Reigstad M Upward nitrate flux and downward particulate organic carbon (POC) flux along a gradient of stratification and turbulent mixing in an Arctic shelf sea, Barents Sea. Manuscript formatted to the standards of Journal of Geophysical Research: Oceans)
  • Paper III Wiedmann I, Reigstad M, Marquardt M, Vader A, Gabrielsen TM Seasonality of vertical flux and sinking particle characteristics in an ice-free high Arctic fjord – different from sub-arctic fjords? Journal of Marine System – in press

Ingrid’s supervisors have been:

  • Marit Reigstad (UiT, Tromsø, Norway)
  • Paul Wassmann (UiT, Tromsø, Norway)
  • Sünnje Basedow (UiN, Bodø, Norway)

You can have a look at Ingrid’s thesis and paper I and III. We wish Ingrid all the best with her future projects!