| Summary: | Sea ice plays a significant role in global climate systems, reflecting a significant portion of solar energy back into the atmosphere and maintaining ocean circulation currents. The effect of climate change on sea ice extent and seasonal changes is as yet unquantified. This is especially true for the initial growth processes and properties within the Antarctic Marginal Ice Zone (MIZ) front during the winter growth season. The Polar Engineering Research Group (PERG) at the University of Cape Town has conducted several research expeditions to the Antarctic MIZ along the 0° line of longitude, collecting samples of first year sea ice. Artificial sea ice has been used as a supplementary area of study because of the advanced control it provides over variables such as cooling rate or initial solution salinity. This allows for the effect of individual variables to be analysed through repeated experiments while adjusting only the variable of interest. Due to the complex nature and conditions of formation for Antarctic sea ice, this study focusses on the key properties of sea ice formed in predominantly calm conditions. These are observed as vertically elongated ice crystals with a c-axis located randomly within the horizontal plane. The profile of ice thickness over time displays a √ x shape. Brine inclusions are located in vertically orientated, interconnected channels, contained within the intracrystalline planes. The crystal planes have spacings of about 1 mm. Lastly, the salinity profile of the ice displays a characteristic c-shaped curve with depth, with higher values of salinity found at the top and bottom of the ice. Ice fitting this description is referred to as columnar S2 ice. The overall aim of this project is to design and test a small-scale system for the growth of artificial sea ice. This system will still enable method development of testing protocols for the testing of the Antarctic sea ice. Once this system has proven to reliably produce saline ice that can be termed as artificial sea ice with a columnar ...
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