An Experimental Investigation of Turbulence-Enhanced Ice Melting

Melting in polar regions has been hypothesized to be heavily influenced by turbulence, as turbulence continually stirs away the meltwater surrounding the ice to replenish warmer ambient fluid adjacent to the ice, thus encouraging efficient melting. However, a quantification of how turbulence, when coupled with ambient salinity and temperature, increases melt rates has yet to be determined. To understand the fundamental physics by which turbulence, salinity, and temperature affect melting rates, we have designed an experimental study that explores melting of an ice sphere centered in homogeneous isotropic turbulence absent mean flow. Particle image velocimetry is used to measure the velocity field of the ambient water and meltwater; statistics including turbulent kinetic energy, dissipation rates, and integral scales are computed directly. By dyeing the ice sphere fluorescent, simultaneous laser-induced fluorescence measurements are used to instantaneously visualize and quantify melting in response to turbulent dynamics. Time-lapse photography is used to quantify ice loss in time. A full quantification of melting is presented across a wide parameter space exploring contributions from ambient turbulence, salinity, and temperature in a zero mean shear environment.