This project aims to determine the sensitivity of the Greenland Ice Sheet and glaciers in northwestern 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.

Due to poorly constrained atmospheric concentrations of ice nucleating particles in the arctic, it is difficult to estimate the radiative energy budged of this area. The marine microlayer, the bacterioneuston, is an important source of biological ice-nucleating particles, in particular during the period of high primary production and in regions with low concentrations of these particles, such as the arctic. In this multidisciplinary project we will study the contribution of marine emissions to the atmospheric bio-particulate matter, with a particular focus on biological ice nucleators.

In the atmosphere, atmospheric particles are acting as short-lived climate forcers and are assumed to be responsible for a part of the climate changes observed worldwide. In the Arctic, a large fraction of observed aerosols is long-range transported especially in late winter and early spring (Arctic haze).

This project will produce substantial new information on the role of climate in shaping arctic biodiversity and how it will respond to climate change. Specifically, we will collect and identify arthropods using standardized protocols along local and regional climatic gradients, stratified according to vegetation types in Greenland. We have already completed similar campaigns at Godthåbsfjorden (2013) and Young Sound (2014) and South Greenland (2014-2015).

This project will produce substantial new information on the role of climate in shaping arctic biodiversity and how it will respond to climate change. Specifically, we will collect and identify arthropods using standardized protocols along local and regional climatic gradients, stratified according to vegetation types in Greenland. We have already completed similar campaigns at Godthåbsfjorden (2013) and Young Sound (2014) and South Greenland (2014-2015).

Measurements of mercury distributions in sea ice cores have revealed elevated total mercury concentrations in sea ice relative to underlying seawater. Although field data are limited, total mercury concentrations also appear to be greatly enriched in surface layers of sea ice.

Precise estimation of sea ice thickness and ice/brine ratio are difficult to be made in situ. Electromagnetic methods are the most suitable techniques to evaluate such parameters as they can be inferred starting from the dielectric properties of the ice.

The recently discovered dynamic exchange of carbon between the atmosphere, sea ice, and underlying marine water has shown the importance of a geochemical pump driven by sea ice formation and dissolution. The creation of sea ice brine (with elevated CO2 concentrations due to ice exclusion and carbonate precipitation) and its eventual vertical migration provides an efficient mechanism for transferring carbon into the deeper water column.

Satellite observations are ideal for the synoptic observation of expansive and inaccessible areas, serving as both primary and secondary sources of information. However, global observing systems and in particular studies requiring different spatial resolutions and long time bases require accurate knowledge of sensor to sensor biases. Therefore the responsivities of all optical radiometers operated in space need to be intercompared and traceable to a common reference standard.

The overall aim of the field campaign is to provide insight on the structure and function of arctic tundra ecosystems.