This project aims to determine the sensitivity of the Greenland Ice Sheet and glaciers in northeastern Greenland to climate changes during our current interglacial period, the Holocene (the past 11,650 years). We will determine the timing and magnitude of past ice fluctuations using lake sediments near the ice margins and surface exposure dating of glacial landforms. We will also extract lake sediment cores from isolated lake basins near the coast to reconstruct relative sea level changes.

This subproject will conduct a survey of ecosystem trace gas exchanges in both terrestrial, limnic and near coastal water. The survey will be conducted with a novel mobile automatic chamber based system combined with a new portable laser based multigas analyser. The main focus of the survey will be the terrestrial ecosystems and the scale of fluxes in this extreme high arctic environment at the height of the growing season will be compared with the long-term record of terrestrial trace gas exchanges avalaible from the Greenland Ecosystem Monitoring program at Zackenberg.

The objectives are to describe the near-shore dynamics, circulation and hydrography around St. Nord and the nearby ice tongue from the Flade Isblink glacier. CTD measurements will be carried out from boat along transects in the open water area around St. Nord and CTD casts will also be made near the near-by Ice tongue, from Flade Isblink glacier, east of the station. The shallow mooring near St. Nord (mounted during spring) will be taken up and a preliminary data analysis will be made.

An automated underwater vehicle (AUV) equipped with CT, pCO2, pH sensors will be deployed in the open water near the Station. This instrument will map the variability of the water characteristics and supports the CTD measurements taken during the area surveys. The possibilities and limits of this instrument will be tested.

Field Site: Villum Research Station, Station Nord, Greenland

PI: Søren Rysgaard

Ice algae are important plants supporting food webs in the Arctic, especially during spring and early summer when there is very little phytoplankton in the water. The aim of this project is to determine photosynthetic responses and acclimation of sea ice algae to changes in their light climate, especially as governed by differences in snow thickness.

Following up on the scientific questions to be addressed, the major tasks from a particle perspective are:

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 goal of this project is to determine the role of the snow on the inorganic carbon dynamic, associated with the evolution of the algal community changes under different snow cover.

In this SERF project we investigate the possibility of retrieval of physical properties of bare sea ice from in-situ microwave remote sensing measurements.

Time series C-band (5.5 GHz) fully-polarimetric  scatterometer data from sea ice during the initial ice formation will be collected. The inverse scattering model will be applied to the collected data to reconstruct changes of brine volume content in sea ice. The obtained results will be verified against in-situ data. Lead – Nariman Firoozy.

During sea ice formation, a portion of seawater is trapped in the ice matrix, resulting in concentrated brine. The nutrients in sea ice brine are expected to behave conservatively as a function of brine salinity. However, it is often found that the salinity-normalized nutrients in sea ice brine are depleted compared to those in the surface seawater, which is normally attributed to biological activity. Here we ask the question, are there other factors that can affect nutrient concentration in sea ice?