The effect of a salinity gradient on the dissolution of a vertical ice face

We investigate experimentally the effect of stratification on a vertical ice face dissolving into cold salty water. We measure the interface temperature, ablation velocity and turbulent plume velocity over a range of salinity gradients and compare our measurements with results of similar experiments without a salinity gradient (Kerr & McConnochie, J. Fluid Mech, vol. 765, 2015, pp. 211-228; McConnochie & Kerr, J. Fluid Mech., vol. 787, 2016, pp. 237-253). We observe that stratification acts to reduce the ablation velocity, interface temperature, plume velocity and plume acceleration. We define a stratification parameter, S = N-2/Phi(0), that describes where stratification will he important, where N is the Brunt-Vaisala frequency, Q is the height-dependent plume volume flux and Phi(0) is the buoyancy flux per unit area without stratification. The relevance of this stratification parameter is supported by our experiments, which deviate from the homogeneous theory at approximately S = 1. Finally, we calculate values for the stratification parameter at a number of ice shelves and conclude that ocean stratification will have a significant effect on the dissolution of both the Antarctic and Greenland ice sheets.