The changing climate has resulted in a significant reduction of sea ice cover in the Arctic Ocean. However, information on the variability of sea ice is limited to the satellite period (i.e. ca 30 years), and ice sheet melting rates is known from an even shorter period. This hampers our understanding of the natural, background state of the climate and environment, and is even more evident for the NE Greenland region, where basically no studies have yet been carried out focussing on this aspect.

The current project aims at reconstructing past variability of sea ice in the Station Nord Region and its impact on the biogeochemical cycle, especially plankton organisms. The study will be based on sediment cores taken from the sea floor. These cores will be studied for their sediment composition, where sediment structures and grain size combined with trace elements (XRF core scanning) is expected to document changes in sea ice over recent millennia. The cores will also provide information on ice sheet melting rates. Further analyses will include IP25, dinoflagellate cysts and diatoms, which will illustrate variability in sea ice cover as well as meltwater influx and temperature of the surface waters. Benthic foraminifera that may be used to test for influx of ocean water as a bottom water into the fjord. The temperature of these bottom waters are expected to have a major impact on glacier melting rates, whereas its significance for sea ice is yet uncertain.

We will also collect surface sediment samples as well as samples from the sea ice to study IP25, the modern plankton and sea ice assemblages, and their DNA.

Field Site: Villum Research Station, Station Nord, Greenland

PI: Marit-Solveig Seidenkrantz

Field participants: Niels Nørgaard-Pedersen and Sofia Ribeiro