A one-dimensional (1-D), thermodynamic sea-ice model with parameterized ice
dynamics is coupled to a mixed-layer ocean model and driven with prescribed
atmospheric forcings for the central Arctic. The model is used to calculate
the sensitivity of the ice pack to various parameterizations that have
traditionally been neglected or considered only implicitly in large-scale
sea-ice models. The model includes melt ponds, leads (with summertime
stratification), an ice-export term, a stability-dependent air–sea
heat-exchange coefficient, a prognostic ocean–ice heat exchange, a crude
ice-thickness distribution, and a sophisticated albedo parameterization.
The ice pack is sensitive to the partitioning of solar energy between
lateral melting and mixed-layer warming, with the most realistic simulations
occurring when the heat is nearly evenly divided between these two
processes. Conversely, ice thickness and coverage are fairly insensitive to
the amount of lateral mixing within the upper ocean, vertical mixing within
leads, and to the partitioning of mixed-layer heat content between warming
the water and melting the ice bottom. The ice concentration during summer is
strongly dependent on the assumed ice-thickness distribution: the amount of
open water during summer is less than half the size of the empirically based
distribution used here, compared with one in which ice floes are distributed
uniformly across a range of thicknesses.