Five Months of Arctic Turbulence and Heat Flux Observations from the Norwegian Young Sea Ice Cruise (N-ICE2015)

Understanding heat fluxes between the ocean and the sea ice in the Arctic is of fundamental importance to understanding the new first year sea ice regime and consequences for regional and global ocean circulation. Here we present preliminary results from the Norwegian Young sea Ice cruise (N-ICE2015) that took place between January and June 2015 in the Arctic Ocean north of Svalbard.

In January 2015, the Norwegian research vessel Lance was frozen into the ice at 83o.3N 21.5oE. Research instruments were deployed on the ice to collect oceanographic, atmospheric, sea ice, snow and biological data while the Lance was drifting south toward the ice edge. Over the following six months, a total of four drifts took place.

Throughout the drifts, the oceanography package collected turbulence measurements to estimate heat, salt, and momentum fluxes in the ice-ocean boundary layer and between the sub-surface Atlantic Water layer and the ice-ocean boundary layer. Water tracer data was collected to map water mass properties, describe freshwater sources, and the distribution of the Atlantic Water inflow.

Here we present under-ice heat flux estimates from microstructure profiler observations spanning five months, from the deep Nansen Basin to the Yermak Plateau. During this period, several large low-pressure events took place, inducing strong winds and ice drift, while strong tidal signals were observed on the Plateau. In the light of such conditions, we investigate processes behind the vertical transport of heat between the Atlantic Water layer and the surface mixed layer.