Author(s): Petra Heil; Jennifer K. Hutchings; William D. Hibler Iii
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Keywords: No Keywords
Abstract: The Arctic sea ice is affected by deviations from the mono state climatological conditions (expressed by the Northern Hemispheric Annual Mode, NAM) of the atmosphere. A long-term simulation with a dynamic thermodynamic sea-ice model including inertial embedding is conducted to explore how the non-linear energy cascade from low to subdaily frequencies evolves under atmospheric changes. Concentrating on years with extreme high or low NAM indices we are able to analyse the behaviour of the sea ice during extreme atmospheric states. Initial analysis suggest the existence of a bi-modal pattern for ice velocity and deformation, in correspondence with high and low NAM. The active (passive) mode falls generally within high (low) NAM. The frequency distribution of energy associated with sea-ice motion varies temporally with an intensification of the non-linear energy cascade during high NAM. This change in the energy transfer function is believed to be facilitated by changes in the physical quality (e. g., thickness and strength) of the sea ice.
Year: 2002