THE RELATION BETWEEN ICE DEFORMATION, OCEANIC HEAT-FLUX, AND THE ICE THICKNESS DISTRIBUTION IN THE ARCTIC-OCEAN

A one-dimensional ocean model, coupled with an ice model where the ice cover is partitioned into a number of thickness categories, is used t o investigate how the ice thickness distribution in the Arctic Ocean d epends on the two deformation processes, export (net divergence) and r idging. The model standard case generates vertical profiles of tempera ture, salinity and an ice thickness distribution similar to the observ ations. The standard case oceanic heat flux agrees well with recently deduced heat fluxes from Arctic Ice Dynamics Joint Experiment (AIDJEX) data. The oceanic heat flux is about 18 W m(-2) during summer and abo ut 1 W m(-2), during winter. It is found that the mean ice thickness d ecreases with increasing ice export in close agreement with other inve stigations. However, the dependence of the mean ice thickness on ridgi ng activity is found to be very weak. The change of the mean ice thick ness is only 12 cm when increasing the ridging activity in the model f rom 0 to 0.4 yr(-1); where the larger value represents an estimate of the actual ridging activity in the Arctic Ocean. In a sensitivity stud y, different types of ridging and albedo parameterizations are tested, and this weak dependence is found to be very robust. Other properties of the model ice cover are sensitive to ridging though: The equilibri um thickness of undeformed ice decreases with both export and ridging activity. The annual maximum open water fraction and the amplitude of the seasonal thickness variation increases with export and ridging.