Dynamics of the Antarctic Seasonal Ice Zone

The seasonal sea ice zone (SIZ) on the southern flank of the Antarctic Circumpolar Current is the region in which sea ice undergoes a massive seasonal cycle in its thickness and extent. The SIZ extends all the way around Antarctica and it is here that sea-ice manufacture and export leads to brine rejection and loss of buoyancy in the water column. In this way cold surface waters are preconditioned for subsequent convection, mixing and entrainment in coastal polynyas, under ice shelves and over the continental slope of Antarctica. The transformed (densified) waters ultimately make up Antarctic Bottom Water feeding the lower cell of the Southern Ocean (SO), connecting to the abyssal oceans. Despite the importance of the SIZ in driving the meridional circulation of the ocean-atmosphere climate system, its dynamics is not well observed, modeled or understood. This study seeks to model the fluid dynamics of the seasonal cycle of sea-ice formation in a strongly eddying region next to the continental shelf.

The broad impacts of the research center upon the Antarctic being a system of such great importance to global ocean circulation, and to climate. The study intends to bring together theory, observations and models to address the contemporary problem of uptake of heat to the abyssal ocean, and will provide a challenging context for the education of graduate students and postdoctoral researchers in interdisciplinary science. The development of MITgcm, an open source ocean model used by many, will also continue.