Flow-induced morphological instability of a mushy layer

A morphological instability of a mushy layer due to a forced flow in the me lt is analysed. The instability is caused by flow induced in the mushy laye r by Bernoulli suction at the crests of a sinusoidally perturbed mush-melt interface. The flow in the mushy layer advects heat away from crests which promotes solidification. Two linear stability analyses are presented: the f undamental mechanism for instability is elucidated by considering the case of uniform flow of an inviscid melt; a more complete analysis is then prese nted for the case of a parallel shear flow of a viscous melt. The novel ins tability mechanism we analyse here is contrasted with that investigated by Gilpin et al. (1980) and is found to be more potent for the case of newly f orming sea ice.