ABSTRACT
According to NASA (National Aeronautics and Space Administration), Antarctic sea ice reached its lowest extent ever recorded by satellites at the end of summer 2017 after decades of moderate sea ice expansion. Besides a strong influence on the global climate, linking the exchange of energy and gases between the atmosphere and the ocean, changes in sea ice also have a biological impact on the structure and function of the ecosystem. These effects are strongly related to the physical and mechanical properties of the sea ice structure.
Seawater is trapped in so-called brine pockets during the growth of sea ice, providing a natural habitat for sea ice microorganisms. The microorganisms are supplied with nutrients they need for primary production from the seawater. A small-scale modeling of the porosity of the sea ice and its inclusions and the solid/brine multiphase microstructure, respectively, thermodynamics of air-sea interactions as well as sea ice-biological linkages is a necessary tool to better understand the heterogeneous nature of sea ice.
Based on the extended Theory of Porous Media (eTPM), the development of a multiphasic, multi-component model which enables the continuum mechanical description of transport and phase transition phenomena in sea ice at a homogenized pore scale is developed. The foundation builds a biphasic (ice and brine) model, in which the brine is composed of freshwater and salt.
