Aarhus University Seal / Aarhus Universitets segl

Under-ice dynamics and coastal polynya interaction

2014.03.03 | Egon Randa Frandsen

Date Tue 29 Apr Thu 12 Jun
Time 00:00    00:00
Location Daneborg, N.E. Greenland

This project’s objective is to assess water dynamics in the Young Sound Fjord and adjoining coastal polynya region. This project is aimed to examine the role of topography and sea ice for modifying water dynamics and related vertical mixing. The tidal-driven and buoyancy-driven mixing are of primarily interest. The neap-spring cycle of vertical mixing rate depending on distance from fast-ice edge and bottom topography will be investigated. The project will provide data to analyze the impact of coastal polynya on the sea-ice thermodynamic growth, the sea-ice crystallographic structure, brine rejection, buoyancy-driven mixing and the gas exchange. Furthermore, an artificial pond will be made to investigate the coupling of brine rejection and pCO2.

The project started in October 2013 when we installed 4 MMP/CTD/ADCP land-fast ice-tethered moorings and 2 mass balance buoys in the Fjord. During the 2014 field season, we will evaluate the impact of the coastal polynya on water dynamics and thermo-haline structure from winter to late spring. CTD transects crossing the land-fast ice edge will be made from the beginning of the campaign in May to the brake-up in late June. This involves both land-fast ice and open water CTD profiling and water sampling. In addition, ADCP measurements and microstructure turbulence measurements below the land-fast ice will be conducted. The microstructure turbulent measurements will complement the mooring observations. These measurements will provide the direct evidence of vertical mixing caused by different forcing allowing direct estimates of their efficiency and associated heat and salt fluxes.

PI: Igor Dmitrenko

Environment, climate and energy, Arctic Research Centre