Interactions between Irregular Wave Fields and Sea Ice: A Physical Model for Wave Attenuation and Ice Breakup in an Ice Tank

Abstract

Irregular, unidirectional surface water waves incident on model ice in an ice tank are used as a physical model of ocean surface wave interactions with sea ice. Results are given for an experiment consisting of three tests, starting with a continuous ice cover and in which the incident wave steepness increases between tests. The incident waves range from causing no breakup of the ice cover to breakup of the full length of ice cover. Temporal evolution of the ice edge, breaking front and mean floe sizes are reported. Floe size distributions in the different tests are analysed. The evolution of the wave spectrum with distance into the ice-covered water is analysed in terms of changes of energy content, mean wave period and spectral bandwidth relative to their incident counterparts, and pronounced differences are found between the tests. Further, an empirical attenuation coefficient is derived from the measurements and shown to have a power-law dependence on frequency comparable to that found in field measurements. Links between wave properties and ice breakup are discussed.

Wind waves in sea ice of the western Arctic and a global coupled wave-ice model

“…Local wind waves that are generated far inside the MIZ may have impacts on sea ice evolution and ocean mixing that have not been investigated. Wind waves could enhance ice melt through overwash—occurring when waves cause water to spill over the edge of an ice floe—which is an active area of research [57,58]. If local waves are strong enough to cause fracture, they could reduce sea ice to small floe sizes.…”

Physical and mechanical properties of winter first-year ice in the Antarctic marginal ice zone along the Good Hope Line

“…However, with regards to its mechanical properties including elasticity and strength as well as their directional dependency, a complete lack of data is found, except for in the case of uniaxial compression strength of Antarctic land-fast ice (Urabe and Inoue, 1988b). Accurate knowledge of mechanical ice properties is important to parameterize realistic small-scale sea ice dynamics models with respect to aspects concerning, for example, the influence of pancake ice floe deformation on the inelastic collision restitution (Herman et al, 2019), ridging (Yiew et al, 2017) and fracture (Weiss, 2013) as well as on the wave-induced flexural break-up of consolidated pack ice (Passerotti et al, 2022). These mechanical phenomena are strongly linked to sea ice formation and retreat, sea ice drift, and wave attenuation in the Antarctic MIZ (Alberello et al, 2020;Eayrs et al, 2019;Kohout et al, 2014;Rogers et al, 2016;Smith and Thomson, 2019).…”

Theoretical framework for the emergent floe size distribution in the marginal ice zone: the case for log-normality

“…Recent evidence from field measurements [20,21], laboratory experiments [19,22] and model simulations [23,24] of wave-induced sea ice breakup further suggest that the FSD is not monotonically decreasing and instead has one or two clearly defined modes. The power law is commonly used throughout science to describe heavy-tailed empirical relationships between quantities and statistical distributions [25], but upon close inspection, few only seem to be statistically justified [26].…”