Project Details
Projekt
AEI-DFG Denmark Strait - Mixing and Sediment Dynamics
Subject Area
Oceanography
Geology
Geology
Term
since 2024
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 541914507
The boundary of the oceans – their bathymetry or topography – sets both the geometry of ocean basins (depth and width), and also guides the shape of the large-scale ocean circulation (gyres and currents). Smaller scale features (i.e., coastline shape, straits, submarine sills, cross-shelf troughs, ridges and canyons) further steer the ocean circulation and drive mixing. The Denmark Strait (DS) is one of several chokepoints in the large-scale Atlantic circulation, where a narrow and shallow sill separates the Arctic from the wider Atlantic basin, affecting the rate at which dense waters formed in the Arctic can enter the North Atlantic, and influencing how those dense waters are mixed. Along the eastern margin of Greenland, the ocean circulation is generally in the southward direction, with narrow and fast boundary currents (1 m/s or more) along the sloping bathymetry between Fram Strait and DS. At the DS, the overflow of dense water is a bottom-intensified current. Here, the bathymetry-flow interaction operates
in two directions: (1) with the topography steering the flow or providing drag to induce shear and, subsequently, mixing in the flow, and (2) with the intense flow and its variations in space and time contributing to shaping the seabed. In this project, we propose to assess flow-topography interactions to understand their role in ocean mixing at the submesoscale (1–10 km), and their contribution to transporting sediments and shaping the seabed. This will elucidate the potential role of these small-scale processes in influencing the large-scale ocean circulation and the biogeochemical conditions in the North Atlantic. This project will address how small-scale processes at the ocean floor shape the large-scale ocean circulation, sediment dynamics and seabed topography. MIXSED will address the following specific objectives: O1: Diagnose the mesoscale/submesoscale dynamics in the vicinity of strongly sheared flows and complex topography, O2: Characterise particles transported and the capacity of the DSO to shape the seafloor, in the context of the intensity of flows and physical mixing processes, O3: Evaluate the potential for two-way flow-topography interactions in the region of DSO, conceptually and, where possible, practically. This project capitalises on new methods developed to diagnose submesoscale variability in the ocean in order to address the role of small-scale processes and flow-topography interactions in modulating the large-scale circulation and seabed morphology.
DFG Programme
Research Grants
International Connection
Spain
Partner Organisation
Agencia Estatal de Investigación
