Accounting of the internal structure of the ice hummock keel in thermodynamic calculations of the evolution of the consolidated layer

Abstract

Materials from long-term field observations of the internal structure of ice hummocks in the Arctic seas were analyzed. Empirical expressions describing the porosity distribution of the underwater part of a newly-formed hummock depending on the depth and width of the keel had been derived. A two-dimensional thermodynamic ice hummock model taking into account these expressions has been developed. The influence of porosity distribution on the results of thermodynamic calculations of ice hummock evolution is considered. It is shown that the porosity distribution in the ice hummock keel defines the growth of the consolidated layer to a large extent. The screening effect of the ice hummock sail on the evolution of the consolidated layer is less important. As a result, during the life-time of the ice hummock, the thickness of the consolidated layer in its central part becomes greater than at its edges. The smaller the size of the ice hummock, the faster this effect appears.

Keywords

• arctic regions
• internal structure
• hummock
• porosity
• ridge keels
• two-dimensional thermodynamic model of ice hammock