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

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.

scholarly journals A Computational Fluid Dynamics Model for the Small-Scale Dynamics of Wave, Ice Floe and Interstitial Grease Ice Interaction

Fluids ◽  
2021 ◽  
Vol 6 (5) ◽  
pp. 176
Author(s):  
Rutger Marquart ◽  
Alfred Bogaers ◽  
Sebastian Skatulla ◽  
Alberto Alberello ◽  
Alessandro Toffoli ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Sea Ice ◽  
Strain Rate ◽  
Large Scale ◽  
Ocean Waves ◽  
Small Scale ◽  
Drag Forces ◽  
Marginal Ice Zone ◽  
Ice Floes

The marginal ice zone is a highly dynamical region where sea ice and ocean waves interact. Large-scale sea ice models only compute domain-averaged responses. As the majority of the marginal ice zone consists of mobile ice floes surrounded by grease ice, finer-scale modelling is needed to resolve variations of its mechanical properties, wave-induced pressure gradients and drag forces acting on the ice floes. A novel computational fluid dynamics approach is presented that considers the heterogeneous sea ice material composition and accounts for the wave-ice interaction dynamics. Results show, after comparing three realistic sea ice layouts with similar concentration and floe diameter, that the discrepancy between the domain-averaged temporal stress and strain rate evolutions increases for decreasing wave period. Furthermore, strain rate and viscosity are mostly affected by the variability of ice floe shape and diameter.

Surface Waves Under the Sea Ice in the Western Arctic During 2019 R/V Mirai Cruise

2020 ◽  
Author(s):  
Tsubasa Kodaira ◽  
Takuji Waseda ◽  
Takehiko Nose ◽  
Jun Inoue ◽  
Kazutoshi Sato ◽  
...  
Keyword(s):  
Sea Ice ◽  
Surface Waves ◽  
Ocean Waves ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Wave Transformation ◽  
Sea Ice Extent ◽  
Marginal Ice Zone ◽  
Western Arctic ◽  
Arctic Climate Change

Abstract Surface ocean waves are one of the potential processes that influence on the Arctic sea-ice extent. A better understanding of the generation, propagation, and attenuation of ocean waves under the sea ice is necessary to discuss the future Arctic climate change. We deployed two drifting wave buoys in the marginal ice zone in the western Arctic. Since the surface wave observation in the marginal ice zone is rare, the obtained data are useful for validation of the numerical modeling of the surface waves under the sea ice. The first buoy was deployed in the pancake-ice covered area and the second one in the open ocean. The distance between the two buoys at the deployment was about 40km, and the second buoy was deployed approximately 5 hours after the first deployment. The comparison of the wave bulk statistic measured by the two buoys shows the wave transformation under the sea ice. In general, the significant wave height decreases, and the mean wave periods increase by the presence of the sea ice.

scholarly journals A prognostic model of the sea-ice floe size and thickness distribution

2015 ◽  
Vol 9 (6) ◽  
pp. 2119-2134 ◽  
Author(s):  
C. Horvat ◽  
E. Tziperman
Keyword(s):  
Wave Propagation ◽  
Sea Ice ◽  
Prognostic Model ◽  
Climate Models ◽  
Thickness Distribution ◽  
Lateral Side ◽  
Test Cases ◽  
Multiple Processes ◽  
Marginal Ice Zone ◽  
Oceanic Forcing

Abstract. Sea ice exhibits considerable seasonal and longer-term variations in extent, concentration, thickness, and age, and is characterized by a complex and continuously changing distribution of floe sizes and thicknesses, particularly in the marginal ice zone (MIZ). Models of sea ice used in current climate models keep track of its concentration and of the distribution of ice thicknesses, but do not account for the floe size distribution and its potential effects on air–sea exchange and sea-ice evolution. Accurately capturing sea-ice variability in climate models may require a better understanding and representation of the distribution of floe sizes and thicknesses. We develop and demonstrate a model for the evolution of the joint sea-ice floe size and thickness distribution that depends on atmospheric and oceanic forcing fields. The model accounts for effects due to multiple processes that are active in the MIZ and seasonal ice zones: freezing and melting along the lateral side and base of floes, mechanical interactions due to floe collisions (ridging and rafting), and sea-ice fracture due to wave propagation in the MIZ. The model is then examined and demonstrated in a series of idealized test cases.

scholarly journals Numerical Study on Wave-Ice Interaction in the Marginal Ice Zone

2020 ◽  
Vol 9 (1) ◽  
pp. 4
Author(s):  
Tiecheng Wu ◽  
Wanzhen Luo ◽  
Dapeng Jiang ◽  
Rui Deng ◽  
Shuo Huang
Keyword(s):  
Sea Ice ◽  
Numerical Study ◽  
Test Results ◽  
Towing Tank ◽  
Marginal Ice Zone ◽  
Computational Fluid Dynamics Cfd ◽  
Numerical Research ◽  
Ice Floes ◽  
Cfd Method ◽  
Six Degree Of Freedom

The effect of waves on ice sheet is critical in the marginal ice zone (MIZ). Waves break large sea ice into small pieces and cause them to collide with each other. Simultaneously, the interaction between sea ice and waves attenuates these waves. In this study, a numerical research is conducted based on a computational fluid dynamics (CFD) method to investigate the response of single ice floe to wave action. The obtained results demonstrate that the sea ice has a violent six degree of freedom (6DoF) motion in waves. Ice floes with different sizes, thicknesses, and shapes exhibit different 6DoF motions under the action of waves. The heave and surge response amplitude operator (RAO) of the sea ice are related to wavelength. Furthermore, the overwash phenomenon can be observed in the simulation. The obtained results are compared with the model test in the towing tank based on artificial ice, and they agree well with test results.

scholarly journals Brief communication: Pancake ice floe size distribution during the winter expansion of the Antarctic marginal ice zone

2018 ◽  
Author(s):  
Alberto Alberello ◽  
Miguel Onorato ◽  
Luke Bennetts ◽  
Marcello Vichi ◽  
Clare Eayrs ◽  
...  
Keyword(s):  
Sea Ice ◽  
Size Distribution ◽  
Marginal Ice Zone ◽  
Ice Floes ◽  
The Antarctic

Abstract. The size distribution of pancake ice floes is calculated from images acquired during a voyage to the Antarctic marginal ice zone in the winter expansion season. Results show that 50 % of the sea ice area is made up by floes with diameters 2.3–4 m. The floe size distribution shows two distinct slopes on either side of the 2.3–4 m range. It is conjectured that growth of pancakes from frazil forms the distribution of small floes (D  4 m).

scholarly journals Brief communication: Grease Ice in the Antarctic Marginal Ice Zone

2021 ◽  
Author(s):  
Felix Paul ◽  
Tommy Mielke ◽  
Carina Nisters ◽  
Jörg Schröder ◽  
Tokoloho Rampai ◽  
...  
Keyword(s):  
Sea Ice ◽  
Rheological Properties ◽  
Annual Cycle ◽  
Flow Behavior ◽  
Ocean Waves ◽  
Ice Cover ◽  
Ice Crystals ◽  
Frazil Ice ◽  
Marginal Ice Zone ◽  
The Antarctic

Abstract. Frazil ice, consisting of loose disc-shaped ice crystals, is the very first ice that forms in the annual cycle in the marginal ice zone (MIZ) of the Antarctic. A sufficient number of frazil ice crystals forms the surface grease ice layer taking a fundamental role in the freezing processes in the MIZ. As soon as the ocean waves are sufficiently damped, a closed ice cover can form. In this brief communication we investigate the rheological properties of frazil ice, which has a crucial influence on the growth of sea ice in the MIZ. Grease ice shows shear thinning flow behavior.

scholarly journals Numerical Modelling of Realistic Ice Floes in Ocean Waves

1983 ◽  
Vol 4 ◽  
pp. 277-282 ◽  
Author(s):  
Vernon A. Squire
Keyword(s):  
Numerical Model ◽  
Numerical Modelling ◽  
Rigid Body ◽  
Ocean Waves ◽  
Rigid Body Motions ◽  
Ice Floes ◽  
Wave Induced

Results from a numerical model for the computation of ice-floe motions in ocean waves are presented and discussed for floes of various sectional shapes. It is shown that the beam-to-draft ratio is a crucial factor in determining the behaviour of each floe, and that ridges and keels can substantially affect the roll and sway characteristics, particularly for thick floes. Undercuts beneath floes appear to have little effect, but a protruding sill can lead to decreased motion at certain frequencies and a reduced capability for making waves. As the underwater character of an ice floe cannot easily be measured, it is necessary to infer draft from freeboard estimates using the method proposed by Ackley and others (1976). Although most of this paper is concerned with rigid body motions, a brief account is included of a modification to the model which allows each floe to bend on the passing wave. By this means, wave-induced flexure is discussed for floes of non-simple underwater shape.

scholarly journals Ocean wave speed in the Antarctic marginal ice zone

2001 ◽  
Vol 33 ◽  
pp. 350-354 ◽  
Author(s):  
Colin Fox ◽  
Tim G. Haskell
Keyword(s):  
Wave Propagation ◽  
Large Scale ◽  
Wave Speed ◽  
Ross Sea ◽  
Ocean Waves ◽  
Wave Speeds ◽  
Marginal Ice Zone ◽  
Scale Properties ◽  
Ice Floes ◽  
The Antarctic

AbstractThe propagation of ocean waves in the marginal ice zone (MIZ) is investigated with the aim of determining whether the loading and scattering of waves by ice floes is significant. Measurements made using instrumented ice floes in the MIZ north of the Ross Sea, Antarctica, during June 1998 are used to determine the frequency-wavelength relationship for propagating ocean waves in that region. This measured-dispersion equation is related to the effective large-scale properties of the MIZ that occur in models for wave propagation and scattering. We present the measured wave speeds to enable estimation of the parameters in these models.

scholarly journals Towards a coupled model to investigate wave–sea ice interactions in the Arctic marginal ice zone

2020 ◽  
Vol 14 (2) ◽  
pp. 709-735 ◽  
Author(s):  
Guillaume Boutin ◽  
Camille Lique ◽  
Fabrice Ardhuin ◽  
Clément Rousset ◽  
Claude Talandier ◽  
...  
Keyword(s):  
Sea Ice ◽  
Wave Attenuation ◽  
Coupled Model ◽  
Wave Model ◽  
The Arctic ◽  
Wave Radiation ◽  
Strong Interactions ◽  
Sea Ice Concentration ◽  
Ocean Surface Waves ◽  
Marginal Ice Zone

Abstract. The Arctic marginal ice zone (MIZ), where strong interactions between sea ice, ocean and atmosphere take place, is expanding as the result of ongoing sea ice retreat. Yet, state-of-the-art models exhibit significant biases in their representation of the complex ocean–sea ice interactions taking place in the MIZ. Here, we present the development of a new coupled sea ice–ocean wave model. This setup allows us to investigate some of the key processes at play in the MIZ. In particular, our coupling enables us to account for the wave radiation stress resulting from the wave attenuation by sea ice and the sea ice lateral melt resulting from the wave-induced sea ice fragmentation. We find that, locally in the MIZ, the ocean surface waves can affect the sea ice drift and melt, resulting in significant changes in sea ice concentration and thickness as well as sea surface temperature and salinity. Our results highlight the need to include wave–sea ice processes in models used to forecast sea ice conditions on short timescales. Our results also suggest that the coupling between waves and sea ice would ultimately need to be investigated in a more complex system, allowing for interactions with the ocean and the atmosphere.

scholarly journals Ice-floe kinematics in the Ross Sea marginal ice zone using GPS and accelerometers

2001 ◽  
Vol 33 ◽  
pp. 345-349 ◽  
Author(s):  
Josh Downer ◽  
Timothy G. Haskell
Keyword(s):  
Global Positioning System ◽  
Ross Sea ◽  
Austral Summer ◽  
Positioning System ◽  
Accelerometer Data ◽  
Gps Receivers ◽  
Global Positioning ◽  
Marginal Ice Zone ◽  
Ice Floes ◽  
Wave Induced

AbstractAn experiment to investigate wave-induced floe response and floe-floe interactions was conducted in the Ross Sea marginal ice zone during austral summer 1999. Three types of sensors were used: global positioning system (GPS) receivers; triaxial accelerometers; and compasses. The accelerometer data reveal consistent bands of energy centred at about 0.1 and 1.35 Hz, the latter an unexplained but common feature of such experiments. The GPS data also contain energy near 0.1 Hz, which may suggest that GPS receivers can detect the ocean-wave-induced lateral motion of ice floes.

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