Turbulent Fluxes Near a Thin, Advancing, Sea-Ice Edge

In the marginal ice zone (MIZ) of the Arctic Ocean, it is expected that the turbulent fluxes of momentum and sensible heat are dependent on a number of surface characteristics and processes that impact the surface roughness and stability in the atmospheric surface layer. These include ice concentration, ice thickness, ice freeboard, floe sizes, and ocean wave characteristics (height and period). The range of length scales over which these parameters vary in the MIZ is large. The relationship between some of these characteristics and the turbulent fluxes are represented by recent bulk flux parameterization schemes (e.g., Andreas et al, 2010; Lüpkes et al 2012; Lüpkes and Gryanik 2015). During the Sea State field program in the Beaufort and Chukchi Seas from Oct 3 to Nov 5, 2015, direct covariance and inertial dissipation measurements of the turbulent fluxes were made from the bow of the icebreaker R/V Siquliak, while many of the surface characteristics were also measured from various platforms on board. Hence, this data set provides a good opportunity to explore the relationships between surface characteristics and the turbulent fluxes in the advancing marginal ice zone. Performance of the bulk flux schemes mentioned above will be evaluated in this complex environment and suggestions for improvements made.

This presentation will show the complex surface environment encountered during Sea State, and demonstrate the extent to which existing bulk flux parameterizations can represent the directly measured turbulent fluxes of sensible heat and momentum in this environment.