Day 4

Detailed paper information

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Paper title Impact of the sea ice friction on ocean tides in the Arctic Ocean, modelling insights at various time and space scales
  1. Mathilde Cancet NOVELTIS Speaker
  2. Florent Lyard CNRS-LEGOS
  3. Ergane Fouchet NOVELTIS
  4. Johnny A. Johannessen Nansen Environmental and Remote Sensing Center
  5. Craig James Donlon ESA - ESTEC
Form of presentation Poster
  • A8. Ocean
    • A8.07 Oceanographic Change of the Arctic Ocean From Space
Abstract text The ocean tides are one of the major contributors to the energy dissipation in the Arctic Ocean. In particular, barotropic tides are very sensitive to friction processes, and thus to the presence of sea ice in the Polar regions. However, the interaction between the tides and the ice cover (both sea ice and grounded ice) is poorly known and still not well modelled, although the friction between the ice and the water due to the tide motions is an important source of energy dissipation and has a direct impact on the ice melting. The variations of tidal elevation due to the seasonal sea-ice cover friction can reach several centimeters in semi-enclosed basins and on the Siberian continental shelf. These interactions are often simply ignored in tidal models, or considered through relatively simple combinations with the bottom friction.
In the frame of the Arktalas project funded by the European Space Agency, we have investigated this aspect with a sensitivity analysis of a regional pan-Arctic ocean tide hydrodynamic model to the friction under the sea ice cover, in order to generate more realistic simulations. Different periods of time, at the decadal scale, were considered to analyze the impact of the long-term reduction of the sea ice cover on the ocean tides in the region, and at the global scale. Tide gauge and satellite altimetry observations were specifically processed to retrieve the tidal harmonic constituents over different periods and different sea ice conditions, to assess the model simulations.
Improving the knowledge on the interaction between the tides and the sea ice cover, and thus the performance of the tidal models in the Polar regions, is of particular interest to improve the satellite altimetry observation retrievals at high latitudes, as the tidal signals remain a major contributor to the error budget of the satellite altimetry observations in the Arctic Ocean, but also to generate more realistic simulations with ocean circulation models, and thus contribute to scientific investigations on the changes in the Arctic Ocean.