Wave-in-ice: theoretical bases and field observations

Abstract

There has been a significant increase of studies on wave–ice interactions in the past decades. Through a close look at a representative set of theories, this paper investigates different physical processes that have produced different wave dispersion and attenuation. The existing theories have considered four major processes: scattering, flexural damping, viscoelastic damping and basal friction. Each theory looked into one of these processes and used a different mathematical formulation to model these processes. The low-frequency behaviours of the resulting spectral attenuation in these theories are fundamentally different from each other. Recent field observations have produced a large amount of data to calibrate and validate these theories. The uncertainties in using field measurements to determine attenuation due to ice covers are discussed. Both observational data and applications of these theories in field conditions suggest a multi-physics approach. A number of studies to further the theoretical development are recommended. It will take time for wave-in-ice models to reach the same level of performance as wave models for the open ocean, relying on the combined effort of theoretical, modelling and observational studies. This article is part of the theme issue ‘Theory, modelling and observations of marginal ice zone dynamics: multidisciplinary perspectives and outlooks’.

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

“…However, significant uncertainty remains in our understanding of fundamental aspects of wave-ice physics [5,6]. A major obstacle is that observations of waves in polar oceans are rare and hard to obtain, and existing in situ datasets sample a limited range of ocean and sea ice conditions [7].…”

A prognosticative synopsis of contemporary marginal ice zone research

“…The former source has attracted greater theoretical study to date because it is mathematically more fascinating and is broader in scope than just MIZs. Yet it is likely that the latter, somewhat prosaic, source of energy loss dominates in most situations [27,31], necessitating theories and parametrizations that account for the damping experienced by the waves [32,33].…”

“…There is also an elephant in the room that needs to be accommodated, namely evidence that wind waves can be generated within the MIZ [18] and that during summer these can induce lateral melting of ice floes-especially when their widths are less than about 30 m [35]. Current parametrizations are helpfully investigating how to assimilate waves into coupled sea-ice models, but the parametrizations used to express how ocean waves attenuate in the MIZ are based on linear viscoelasticity, are only part of the story or are implausible physically [8,18,32,33,36]. I stress that this is not meant to be a criticism, as the inclusion of ocean waves in a sea-ice model is a massive undertaking, especially when the sea ice is being modified through break-up as is done in some studies.…”

Modelling wave–ice interactions in three dimensions in the marginal ice zone

“…However, this accuracy is significantly reduced in ice-covered waters. There remains a great deal of debate in the literature about which methodology is most suitable for these conditions [3]. Moreover, the exact mechanism for wave energy attenuation due to floating sea ice remains unknown.…”