Funds are provided for a one-year project consisting of careful analysis of a unique set of field observations leading to characterization of turbulent diffusion, heat fluxes and mixing rates in the waters of the Arctic Ocean. The proposed work has the potential to increase significantly understanding of mixing in the Arctic Ocean and its influence on fluxes of heat, salt and momentum, and will provide insight into the basin-scale distribution of mixing across the Arctic Ocean. The data also enable investigation of the centimeter-scale structure of intrusions, double-diffusive processes, and geothermal heating of the deep waters. The PIs will produce a complete well-documented data set, consisting of raw and analyzed data and mixing estimates.
The data consist of profiles of microscale temperature and conductivity fluctuations, as well as velocity shear, across the deep Canada, Makarov, and Amundsen Basins, and also over the Alpha-Mendeleyev and Lomonosov Ridges. They were collected in 2005 during the trans-Arctic cruise of the Swedish icebreaker Oden. These new and unique measurements are complemented by information from expendable probes, lowered acoustic Doppler current profiler, and a full hydrographic-biogeochemical program. Preliminary analysis shows that the collected data is of very high quality, with low noise levels and contains clear signatures of intensified mixing at a high resolution.
The improved understanding of vertical heat flux from the warm layer of water of Atlantic origin in the Arctic Ocean that is provided by these analyses should enable similarly enhanced understanding of the role of oceanic coupling between the Atlantic and the Arctic Oceans on sea ice loss and climate variability. The analyses may also prove useful in guiding the planning of future observational campaigns in the Arctic Ocean.
