Abstract

Sea ice is a mushy layer – a reactive porous medium of ice crystals with concentrated interstitial brine. The brine can drain out of sea ice into the underlying ocean driven by buoyancy forces and as it does so it creates dissolution channels, called chimneys, from which the dense brine flows as narrow plumes. I shall review the research that has been done on the formation of chimneys, including several different experimental and field studies and mathematical modelling that resolves the flow in individual chimneys and the surrounding mushy layer. Such detailed modelling is too costly for inclusion in global climate models, so I shall conclude with a new, simple one-dimensional model of the evolution of sea ice that takes dynamical account of brine drainage through chimneys.