During the last decade, many marine-terminating outlet glaciers of the Greenland Ice Sheet have experienced accelerated thinning and increased discharge of meltwater and icebergs to the ocean. If these mass losses continue over time or even increase, they will have important implications for global sea-level change and ocean circulation. The observed changes in speed, terminus position and mass flux of marine-terminating glaciers in central west Greenland have been found to be contrasting and highly variable in both space and time. At present the role of the ocean in controlling the behavior of these glaciers is particularly unclear. In this project a hydrographic field study is proposed in a double-fjord system in central west Greenland. This region is of interest since two adjacent glaciers terminating in the two fjords show very different behavior while they reside in a climatological identical region suggesting an important role of the ocean. The proposed survey will consist of 7 CTD and ADCP sections and a tracer sampling program to obtain temperature, salinity, velocities, oxygen isotope and nutrient data. One CTD section shall be taken outside the double-fjord system to obtain the boundary conditions and three sections shall be taken in each fjord. Near each glaciers’ terminus a survey is proposed with an Autonomous Research Vessel to get high resolution data. This project will provide details of the stratification, heat and freshwater fluxes, the freshwater sources, and of differences in flow fields which will provide insights into the fjords’ circulation in each fjord. The observed modes of fjord circulation will be complemented with long-term observations in the fjords and monitoring of the glaciers in collaboration with an ocean mooring program and a glaciology program (funded elsewhere). The newly obtained insights are crucial for predicting future behavior of outlet glaciers in Greenland where an ocean temperature increase of 1.8°C has been projected.
The study of contourite drifts is useful for the reconstruction of the oceanographic and climate history of continental margins since they contain expanded sedimentary sequences characterized by relatively high and continuous accumulation rates. The Fram Strait on the north polar area is the only deep-sea open gate through which Nord Atlantic and Arctic Oceans water masses meet ensuring ocean heat flow exchange. On the Spitsbergen margin the northward flowing current was measured by a moored array at nearly 79° N. The vertical velocity profile indicates the presence of two velocity maxima corresponding to the core of the West Spitsbergen Current at the sea surface, and the Norwegian Deep Sea Water (NSDW) at a depth of ca. 1500 m corresponding to the depth of two recently identified sediment drift south of 78° N. Brine-enriched shelf waters, produced during winter through persistent freezing and brine release in the polynyas of the Barents Sea (particularly on the Storfjorden), are supposed to contribute with sediments input to the northward flowing NSDW. However, the inferred depositional mechanism was not circumstantiated by direct information measured in the area where the sediment drifts were identified. Evaluation and reconstruction of the oceanographic flow regime in this area is important to understand water masses and heat exchange through the Fram Strait Arctic gate and would improve our understanding on sediment drifts accumulation. Yet, the expanded sedimentary sequences will allow high-resolution, detailed age model reconstructions for stratigraphic cross correlation still lacking in this area. PREPARED aim is to investigate and define the present and past oceanographic patterns around the two contourite drifts identified on the eastern side of the Fram Strait. For this we will encompass a full range of time scales, from instantaneous (CTD) and seasonal (moorings) oceanographic measurements, to the recent (box corer) and geological past (calypso core).
Microplastics are an increasing concern worldwide and have been reported in the water column, surface waters, and in sediments. The accumulation and the fate of microplastics are of particular concern as they are almost impossible to remove from the environment. Many plastics are less dense than seawater and float in the sea surface microlayer, however mixing and turbulence could affect their distribution, and their transport in ocean currents is not understood. The distribution and fate of plastics as marine pollutants falls under descriptor ten of the Marine Strategy Framework Directive (MSFD).
There is a need to identify the relationship between source and sink redistribution of microplastics to highlight accumulation hotspots. It is therefore important to look at transport pathways in the ocean, including the Arctic. The oceanic Arctic west of Spitsbergen marks a boundary between two water masses, the more dense water sinks and the bathymetry affects mixing. The aim of the current research is to identify the effect of thermohaline transportation on the distribution and abundance of microplastics in polar waters. Although there is an estimation of potential plastic input to the Arctic, there are currently no studies confirming the presence or absence of Arctic microplastics and it is important to establish whether this form of pollution is present. Ascertaining the extent of microplastic transport through polar currents is a necessary foundation for the examination trophic system interactions and the potential removal of microplastics from the surface layers through thermohaline circulation. This study will be replicable in the future to monitor any long term flux in the amount of microplastics in the environment. This research will provide a novel, replicable method of analysis and contribute towards MFSD requirements for coordinated monitoring of marine litter. This project will redress the limited knowledge of the fate of microplastics in polar environments.