Modelling of brine transport mechanisms in Antarctic sea ice

• Main Author: Cook, Andrea
• Other Authors: Skatulla, Sebastian, Machutchon, Keith
• Format: Master Thesis
• Language: English
• Published: Faculty of Engineering and the Built Environment 2021
• Subjects: multiphase continua; sea ice; brine drainage; theory of porous media; Antarctic; Southern Ocean; Antarc*; Sea ice
• Online Access: http://hdl.handle.net/11427/33605; https://open.uct.ac.za/bitstream/11427/33605/1/thesis_ebe_2021_cook%20andrea.pdf

It is evident that the sea ice cycle, from its formation to its melt, is governed by a complex interaction of the ocean, atmosphere and surrounding continents. Once sea water begins to freeze, physical, biological and chemical processes have implications on the evolution of the sea ice morphology [38]. The distinguishing factor between fresh and sea water ice is brine inclusions that get trapped within the ice pores during freezing. Salt inclusions within frozen ice influence the salinity as well as the physical properties of the sea ice [23]. These brine inclusions form part of a dynamic process within the ice characterized by the movement of brine and phase transition which are the foundation of many of its physical properties [23]. Brine removal subsequently begins to occur due to vertical gravity drainage into the underlying ocean water. This study introduces the application of a biphasic model based on the Theory of Porous Media (TPM) which considers a solid phase for the pore structure of the ice matrix as well as a liquid phase for the brine inclusions, respectively. This work explores the use of the TPM framework towards advancing the description and study of the various desalination mechanisms that are significant in aiding the salt flux into the Southern Ocean. This will foster understanding of brine rejection and how it is linked to the porous microstructure of Antarctic sea ice