On the role of sea-ice transport in modifying arctic responses to global climate change

The role of dynamics in modifying the response of the Arctic ice pack to inter-annually varying forcings and to climate perturbations is investigated using simulations from a two-dimensional ice model and a global climate model (GCM). Inter-annual variability in ice-covered area for 1985-93 is dominated by ice transport, and different transport regimes affect substantially the response of the ice pack to climate perturbations. The thermodynamic-only simulations are more sensitive to initial ice conditions, and respond less than the dynamk-thermodynamic model to small perturbations, but with a greater response to larger perturbations. Comparisons of GCM simulations that use different ice treatments highlights the importance of considering the distribution of ice thickness and extent in assessing climate-change responses.