Laboratory Experiments on Ice Melting: A Need for Understanding Dynamics at the Ice-Water Interface

Abstract

The ice-ocean interface is a dynamic zone characterized by the transfer of heat, salinity, and energy. Complex thermodynamics and fluid dynamics drive fascinating physics as ice is formed and lost under variable conditions. Observations and data from polar regions have shed light on contributions that oceanic currents, meltwater plumes, subglacial hydrology, pressurized bubbles within glacier ice, and other features of the ice-ocean boundary region can make on melting and transport. However, the complicated interaction of mechanisms related to ice loss remain difficult to discern, necessitating laboratory experiments to explore fundamental features of melting dynamics via controlled testing with rigorous measurement techniques. Here, we put forward a review of literature on laboratory experiments that explore ice loss in response to free and forced convective flows, considering melting based on laminar or turbulent flow conditions, ice geometries representing a range of idealized scenarios to those modeling glaciers found in nature, and features such as salinity and stratification. We present successful measurement techniques and highlight findings useful to understanding polar ice dynamics, and we aim to identify future directions and needs for experimental research to complement ongoing field investigations and numerical simulations to ultimately improve predictions of ice loss in our current and evolving climate.

Laboratory experiments of melting ice in warm salt-stratified environments

“…As such, colder heat exchanger temperatures imply that more sensible heat must be delivered to the ice to heat up and melt the ice, but this is a relatively modest effect. Using the Stefan number , where is the specific heat capacity of ice, and is the latent heat of fusion, we estimate that our configuration (with ) requires approximately an extra 11 % of energy for the same melting rate as compared to previous studies where (refer to McCutchan & Johnson 2022). The room temperature was then adjusted to match , and the ice was partitioned off from the freshwater within the tank with a removable barrier slotted flush with the ice face.…”

“…The studies cited above raise the critical question of what flux scaling law best describes the melting rate in stratified environments with active double-diffusive convection. Here, we explore this question by investigating the influence of (relatively weak) salt stratification on the local and depth-averaged melting rates through a series of laboratory experiments at conditions of high thermal driving () with initially uniform far-field temperatures, a regime that previously has not been investigated experimentally (McCutchan & Johnson 2022). In § 2, we outline the experimental set-up and data collection methodology.…”

Advances in monitoring glaciological processes in Kalallit Nunaat (Greenland) over the past decades

“…Submarine melt was theorized by Jenkins (2011) and depends on oceanographic conditions at the terminus (salinity, temperature, velocity), subglacial discharge emerging at the terminus (in turn, this is a function of ice sheet surface melt and subglacial discharge routing), and the shape of the terminus [136]. Testing of this initial theory can be accomplished with in-situ observations (described below) and also in the laboratory, where melting from turbulent plumes can be closely measured and monitored [137].…”

Closing the loops on Southern Ocean dynamics: From the circumpolar current to ice shelves and from bottom mixing to surface waves

“…Laboratory experiments have also played a major role in developing our understanding of key Southern Ocean processes, such as convection (e.g., Vreugdenhil et al, 2017;Gayen & Griffiths, 2022), wave breaking and air-sea exchange (e.g., Melville, 1996;Mayer et al, 2020), jet dynamics (e.g., Von Larcher & Williams, 2014;C. A. Smith et al, 2014), gravity currents (e.g., Griffiths, 1986), mixing and internal waves (e.g., Dossmann et al, 2016;Tan et al, 2022), and ice-ocean interactions (e.g., Aussillous et al, 2006;McCutchan & Johnson, 2022). Laboratory modelling has become less common in recent years, largely due to the relative cheapness and adaptability of numerical modelling.…”