Modelling the response of an ice disc to radial water flow in the context of sea ice thickening

Abstract

Arctic sea ice is melting rapidly, and the Arctic is likely to experience its first ice-free summer in the next few decades unless action is taken locally. One proposed method of reducing or perhaps reversing the melting of Arctic sea ice is pumping seawater onto the surface of the sea ice where it should freeze faster and thicken the ice. This may in turn enable it to last longer or even survive the summer melting period, reflecting more sunlight and becoming stronger multi-year ice with increased resistance to future melting. Despite appearing to be a relatively simple physical problem, the technique has not been researched in depth. Here, the response of ice to water being pumped over its surface is investigated theoretically and experimentally for radial axisymmetric water flow. The dominant heat transfer mechanisms during the period shortly after placement of water onto ice are conduction through the ice away from the water–ice interface and heat transfer from the water to the interface. During this initial period of evolution, advection and radiation to the atmosphere are much smaller in magnitude and hence not included. The heat transfer from the water flow to the interface is modelled for three flows: a well-mixed uniform film flow; a uniform flow with a developing thermal boundary layer; and a laminar, viscous flow with a developing thermal boundary layer. Predictions from these models are compared with data from laboratory experiments using various initial water temperatures. The predictions of the model with a fully developed, laminar viscous flow and a developing thermal boundary layer for the evolution of the ice profile were found to be closest to the data obtained from laboratory experiments with water supplied at 0.5, 1.0 and 1.5 \(^\circ\)C.