Aerial observations of sea ice break-up by ship waves

Mapping Intimacies ◽

10.5194/tc-2021-328 ◽

2021 ◽

Author(s):

Elie Dumas-Lefebvre ◽

Dany Dumont

Keyword(s):

Sea Ice ◽

Flexural Rigidity ◽

Temporal Analysis ◽

Coast Guard ◽

Modal Shape ◽

Lawrence Estuary ◽

Ship Waves ◽

Break Up ◽

Ice Floes ◽

Wave Induced

Abstract. We provide the first in situ observations of floe size distributions (FSD) resulting from wave-induced sea ice break-up. In order to obtain such data, an unmanned aerial vehicle was deployed from the Canadian Coast Guard Ship Amundsen as it sailed in the vicinity of large ice floes in Baffin Bay and in the St. Lawrence Estuary, Canada. When represented as probability density functions weighted by the surface of ice floes, the FSDs exhibit a strong modal shape which confirms the preferential size hypothesis debated in the scientific community. Both FSDs are compared to a flexural rigidity length scale, which depends on ice properties, and with the wavelength scale. This comparison tends to show that the maximal distance between cracks is preferentially dictated by sea ice thickness and elasticity rather than by the wavelength. Temporal analysis of one fracture event is also done. Results show that the break-up advances almost as fast as the wave energy and that waves responsible for the break-up propagate following the mass loading dispersion relation. Moreover, our experiments show that thicker ice can attenuate wave less than thinner ice. This method thus provides key information on the wave-induced FSD, clarifies theoretical aspects from the construction of the FSD to its implementation in models and brings new knowledge regarding the temporal evolution of sea ice break-up.

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WIFF1.0: A hybrid machine-learning-based parameterization of Wave-Induced sea-ice Floe Fracture

10.5194/gmd-2021-281 ◽

2021 ◽

Author(s):

Christopher Horvat ◽

Lettie A. Roach

Keyword(s):

Sea Ice ◽

Climate Models ◽

Ocean Surface ◽

Ocean Waves ◽

Ocean Surface Waves ◽

Marginal Ice Zone ◽

Ice Floes ◽

Global Statistics ◽

Surface Wave Field ◽

Wave Induced

Abstract. Ocean surface waves play an important role in maintaining the marginal ice zone, a heterogenous region occupied by sea ice floes with variable horizontal sizes. The location, width, and evolution of the marginal ice zone is determined by the mutual interaction of ocean waves and floes, as waves propagate into the ice, bend it, and fracture it. In previous work, we developed a one-dimensional “superparameterized” scheme to simulate the interaction between the stochastic ocean surface wave field and sea ice. As this method is computationally expensive and not bitwise reproducible, here we use a pair of neural networks to accelerate this parameterization, delivering an adaptable, computationally-inexpensive, reproducible approach for simulating stochastic wave-ice interactions. Implemented in the sea ice model CICE, this accelerated code reproduces global statistics resulting from the full wave fracture code without increasing computational overheads. The combined model, Wave-Induced Floe Fracture (WIFF v1.0) is publicly available and may be incorporated into climate models that seek to represent the effect of waves fracturing sea ice.

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Experimental evidence for a universal threshold characterizing wave-induced sea ice break-up

10.5194/tc-2020-201 ◽

2020 ◽

Author(s):

Joey Voermans ◽

Jean Rabault ◽

Kirill Filchuk ◽

Ivan Ryzhov ◽

Petra Heil ◽

...

Keyword(s):

Sea Ice ◽

Field Observations ◽

Forecasting Models ◽

Operational Forecasting ◽

Wide Range ◽

Quantitative Manner ◽

Field Campaigns ◽

Break Up ◽

Wave Induced ◽

Promising Avenue

Abstract. Waves can drastically transform a sea ice cover by inducing break-up over vast distances in the course of a few hours. However, relatively few detailed studies have described this phenomenon in a quantitative manner, and the process of sea ice break-up by waves needs to be further parameterized and verified before it can be reliably included in forecasting models. In the present work, we discuss sea ice break-up parameterization and demonstrate the existence of an observational threshold separating breaking and non-breaking cases. This threshold is based on information from two recent field campaigns, supplemented with existing observations of sea ice break-up. The data used cover a wide range of scales, from laboratory-grown sea ice to polar field observations. Remarkably, we show that both field and laboratory observations tend to converge to a single quantitative threshold at which the wave-induced sea ice break-up takes place, which opens a promising avenue for robust parametrization in operational forecasting models.

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Wave‐Induced Surge Motion and Collisions of Sea Ice Floes: Finite‐Floe‐Size Effects

Journal of Geophysical Research Oceans ◽

10.1029/2018jc014500 ◽

2018 ◽

Vol 123 (10) ◽

pp. 7472-7494 ◽

Cited By ~ 5

Author(s):

A. Herman

Keyword(s):

Sea Ice ◽

Size Effects ◽

Ice Floes ◽

Wave Induced

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Experimental evidence for a universal threshold characterizing wave-induced sea ice break-up

The Cryosphere ◽

10.5194/tc-14-4265-2020 ◽

2020 ◽

Vol 14 (11) ◽

pp. 4265-4278

Author(s):

Joey J. Voermans ◽

Jean Rabault ◽

Kirill Filchuk ◽

Ivan Ryzhov ◽

Petra Heil ◽

...

Keyword(s):

Sea Ice ◽

Field Observations ◽

Forecasting Models ◽

Operational Forecasting ◽

Wide Range ◽

Quantitative Manner ◽

Field Campaigns ◽

Break Up ◽

Wave Induced ◽

Promising Avenue

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Break-up of sea ice by ocean waves

Annals of Glaciology ◽

10.3189/s0260305500017869 ◽

1998 ◽

Vol 27 ◽

pp. 438-442 ◽

Cited By ~ 35

Author(s):

Patricia J. Langhorne ◽

Vernon A. Squire ◽

Colin Fox ◽

Timothy G. Haskell

Keyword(s):

Flexural Strength ◽

Sea Ice ◽

Field Experiments ◽

Endurance Limit ◽

Ocean Waves ◽

Fatigue Behaviour ◽

Induced Motion ◽

Break Up ◽

Ice Failure ◽

Wave Induced

The manner in which sea ice breaks up determines its floe-size distribution. This, together with any redistribution due to ocean currents or winds, alters the fluxes between the atmosphere and the underlying ocean. Many materials fail at stresses well below their flexural strength when subject to repeated bending, such processes being termed fatigue. in some materials a stress exists below which the material will maintain its integrity even if subjected to an infinite number of load cycles. This stress is termed the endurance limit. We report a scries of field experiments to investigate the fatigue behaviour of first-year sea ice that subjected in situ cantilever beams to repeated bending with zero mean stress. These tests suggest that an endurance limit exists for sea ice, and that it is approximately 60% of the flexural strength. Using theory and data from wave experiments performed in similar conditions to the fatigue experiments, estimates are made of the conditions under which wave-induced break-up occurs. These indicate that fatigue may be a neglected ingredient of sea-ice failure due to wave-induced motion.

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A device for measuring wave-induced motion of ice floes in the Antarctic marginal ice zone

Annals of Glaciology ◽

10.3189/2015aog69a600 ◽

2015 ◽

Vol 56 (69) ◽

pp. 415-424 ◽

Cited By ~ 22

Author(s):

Alison L. Kohout ◽

Bill Penrose ◽

Scott Penrose ◽

Michael J.M. Williams

Keyword(s):

Sea Ice ◽

Measurement Unit ◽

First Year ◽

Large Wave ◽

Antarctic Sea Ice ◽

Induced Motion ◽

Wave Heights ◽

Ice Floes ◽

Wave Induced ◽

The Antarctic

AbstractA series of wave instruments was deployed on first-year Antarctic sea ice during SIPEX (Sea Ice Physics and Ecosystem Experiment) II. Here we describe the hardware and software design of these instruments and give an overview of the returned dataset. Each instrument consisted of a high-resolution accelerometer coupled with a tri-axis inertial measurement unit, which was located using GPS. The significant wave heights measured near the ice edge were predominately between 1 and 2 m. During the 6 weeks of data capture, several large wave events were measured. We report here a selection of events, highlighting the complexities associated with measuring wave decay at individual frequencies.

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Sizes and Shapes of Sea Ice Floes Broken by Waves–A Case Study From the East Antarctic Coast

Frontiers in Earth Science ◽

10.3389/feart.2021.655977 ◽

2021 ◽

Vol 9 ◽

Author(s):

Agnieszka Herman ◽

Marta Wenta ◽

Sukun Cheng

Keyword(s):

Sea Ice ◽

Size Distribution ◽

Probability Distributions ◽

Satellite Image ◽

Expansion Method ◽

Eigenfunction Expansion Method ◽

Ice Surface ◽

Landfast Ice ◽

Ice Floes ◽

Wave Induced

The floe size distribution (FSD) is an important characteristics of sea ice, influencing several physical processes that take place in the oceanic and atmospheric boundary layers under/over sea ice, as well as within sea ice itself. Through complex feedback loops involving those processes, FSD might modify the short-term and seasonal evolution of the sea ice cover, and therefore significant effort is undertaken by the scientific community to better understand FSD-related effects and to include them in sea ice models. An important part of that effort is analyzing the FSD properties and variability in different ice and forcing conditions, based on airborne and satellite imagery. In this work we analyze a very high resolution (pixel size: 0.3 m) satellite image of sea ice from a location off the East Antarctic coast (65.6°S, 101.9°E), acquired on February 16, 2019. Contrary to most previous studies, the ice floes in the image have angular, polygonal shapes and a narrow size distribution. We show that the observed FSD can be represented as a weighted sum of two probability distributions, a Gaussian and a tapered power law, with the Gaussian part clearly dominating in the size range of floes that contribute over 90% to the total sea ice surface area. Based on an analysis of the weather, wave and ice conditions in the period preceding the day in question, we discuss the most probable scenarios that led to the breakup of landfast ice into floes visible in the image. Finally, theoretical arguments backed up by a series of numerical simulations of wave propagation in sea ice performed with a scattering model based on the Matched Eigenfunction Expansion Method are used to show that the observed dominating floe size in the three different regions of the image (18, 13 and 51 m, respectively) agree with those expected as a result of wave-induced breaking of landfast ice.

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Effects of Wave-Induced Sea Ice Break-Up and Mixing in a High-Resolution Coupled Ice-Ocean Model

Journal of Marine Science and Engineering ◽

10.3390/jmse9040365 ◽

2021 ◽

Vol 9 (4) ◽

pp. 365

Author(s):

Junde Li ◽

Alexander V. Babanin ◽

Qingxiang Liu ◽

Joey J. Voermans ◽

Petra Heil ◽

...

Keyword(s):

High Resolution ◽

Sea Ice ◽

Ice Cover ◽

Ocean Model ◽

Arctic Sea Ice ◽

The Arctic ◽

Ice Melt ◽

Arctic Sea ◽

Break Up ◽

Wave Induced

Arctic sea ice plays a vital role in modulating the global climate. In the most recent decades, the rapid decline of the Arctic summer sea ice cover has exposed increasing areas of ice-free ocean, with sufficient fetch for waves to develop. This has highlighted the complex and not well-understood nature of wave-ice interactions, requiring modeling effort. Here, we introduce two independent parameterizations in a high-resolution coupled ice-ocean model to investigate the effects of wave-induced sea ice break-up (through albedo change) and mixing on the Arctic sea ice simulation. Our results show that wave-induced sea ice break-up leads to increases in sea ice concentration and thickness in the Bering Sea, the Baffin Sea and the Barents Sea during the ice growth season, but accelerates the sea ice melt in the Chukchi Sea and the East Siberian Sea in summer. Further, wave-induced mixing can decelerate the sea ice formation in winter and the sea ice melt in summer by exchanging the heat fluxes between the surface and subsurface layer. As our baseline model underestimates sea ice cover in winter and produces more sea ice in summer, wave-induced sea ice break-up plays a positive role in improving the sea ice simulation. This study provides two independent parameterizations to directly include the wave effects into the sea ice models, with important implications for the future sea ice model development.

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