Imaging the Evolution of Brine Transport in Experimentally Grown Quasi-two-dimensional Sea Ice

Abstract. This article describes the observation techniques and suggests processing methods to estimate dynamical sea-ice parameters from data of the Earth Explorer 10 candidate Harmony. The two Harmony satellites will fly in a reconfigurable formation with Sentinel-1D. Both will be equipped with a multi-angle thermal infrared sensor and a passive radar receiver, which receives the reflected Sentinel-1D signals using two antennas. During the lifetime of the mission, two different formations will be flown. In the stereo formation, the Harmony satellites will fly approximately 300 km in front and behind Sentinel-1, which allows for the estimation of instantaneous sea-ice drift vectors. We demonstrate that the addition of instantaneous sea-ice drift estimates on top of the daily integrated values from feature tracking have benefits in terms of interpretation, sampling and resolution. The wide-swath instantaneous drift observations of Harmony also help to put high-temporal-resolution instantaneous buoy observations into a spatial context. Additionally, it allows for the extraction of deformation parameters, such as shear and divergence. As a result, Harmony's data will help to improve sea-ice statistics and parametrizations to constrain sea-ice models. In the cross-track interferometry (XTI) mode, Harmony's satellites will fly in close formation with an XTI baseline to be able to estimate surface elevations. This will allow for improved estimates of sea-ice volume and also enables the retrieval of full, two-dimensional swell-wave spectra in sea-ice-covered regions without any gaps. In stereo formation, the line-of-sight diversity allows the inference of swell properties in both directions using traditional velocity bunching approaches. In XTI mode, Harmony's phase differences are only sensitive to the ground-range direction swell. To fully recover two-dimensional swell-wave spectra, a synergy between XTI height spectra and intensity spectra is required. If selected, the Harmony mission will be launched in 2028.

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On Modeling the Energetics of the Ridging Process

Journal of Offshore Mechanics and Arctic Engineering ◽

10.1115/1.2919905 ◽

1991 ◽

Vol 113 (2) ◽

pp. 105-108

Author(s):

M. A. Hopkins ◽

W. D. Hibler

Keyword(s):

Sea Ice ◽

Simulation Model ◽

Numerical Experiments ◽

Particle Simulation ◽

Two Dimensional ◽

Floating Layer

A two-dimensional particle simulation model of the sea-ice ridging process is developed. In this model, ridges are formed from a floating layer of disk-shaped rubble compressed between converging multi-year floes. The energy consumed in ridge growth, including dissipation, is explicitly calculated. The results of numerical experiments using this model indicate that the amount of energy required to ridge ice may be two to three times larger than previously thought.

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Two-dimensional Numerical Study on the Growth of Sea Ice Crystals with Flotation of Crystal Nuclei and Its C-axes Distribution

Proceedings of the 8th Pacific Rim International Congress on Advanced Materials and Processing ◽

10.1007/978-3-319-48764-9_352 ◽

2013 ◽

pp. 2839-2846

Author(s):

Yoshiki Kawano ◽

Tetsuya Ohashi

Keyword(s):

Sea Ice ◽

Numerical Study ◽

Ice Crystals ◽

Two Dimensional

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Rheology of an Ice-Floe Field

Annals of Glaciology ◽

10.1017/s0260305500003438 ◽

1984 ◽

Vol 5 ◽

pp. 23-28 ◽

Cited By ~ 20

Author(s):

Iain Bratchie

Keyword(s):

Sea Ice ◽

Energy Loss ◽

Strain Rate ◽

Yield Curve ◽

Sine Wave ◽

Two Dimensional ◽

Number Density ◽

Yield Curves ◽

Develop Theory ◽

Ice Strength

The aim of the paper is (1) to develop theory to describe sea ice as a collection of finite-sized floes and (2) to construct a rheology based on this description.Successful sea-ice models have considered the ice to be a two-dimensional continuum with a nonlinear plastic rheology, a two-dimensional yield curve being used to determine the internal ice stresses as functions of the strain-rate (Hibler 1979). In this paper, the shape but not the size of such a yield curve is derived from an idealized picture of floes as moving discs, randomly distributed in a plane. The expected collision rate, which determines the energy loss, is calculated in terms of the average floe size, the areal floe-number density, and the strain-rate. For the case in which the ice strength is low, the dependence of the energy loss upon the strain-rate implies a lens-shaped yield curve, the curved portions being parts of a sine wave. This compares with circular, tear drop-shaped and elliptical yield curves that have been used in sea-ice models to date (Coon 1974, Colony 1976, Hibler 1979). The applicability of the derived yield curve to cases where the ice strength is not low and significant ridging takes place, such as in a continuous ice cover is discussed.

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Rheology of an Ice-Floe Field

Annals of Glaciology ◽

10.3189/1984aog5-1-23-28 ◽

1984 ◽

Vol 5 ◽

pp. 23-28 ◽

Cited By ~ 2

Author(s):

Iain Bratchie

Keyword(s):

Sea Ice ◽

Energy Loss ◽

Strain Rate ◽

Yield Curve ◽

Sine Wave ◽

Two Dimensional ◽

Number Density ◽

Yield Curves ◽

Develop Theory ◽

Ice Strength

The aim of the paper is (1) to develop theory to describe sea ice as a collection of finite-sized floes and (2) to construct a rheology based on this description.Successful sea-ice models have considered the ice to be a two-dimensional continuum with a nonlinear plastic rheology, a two-dimensional yield curve being used to determine the internal ice stresses as functions of the strain-rate (Hibler 1979). In this paper, the shape but not the size of such a yield curve is derived from an idealized picture of floes as moving discs, randomly distributed in a plane. The expected collision rate, which determines the energy loss, is calculated in terms of the average floe size, the areal floe-number density, and the strain-rate. For the case in which the ice strength is low, the dependence of the energy loss upon the strain-rate implies a lens-shaped yield curve, the curved portions being parts of a sine wave. This compares with circular, tear drop-shaped and elliptical yield curves that have been used in sea-ice models to date (Coon 1974, Colony 1976, Hibler 1979). The applicability of the derived yield curve to cases where the ice strength is not low and significant ridging takes place, such as in a continuous ice cover is discussed.

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Structure of refrozen cracks in first-year sea ice

Canadian Journal of Physics ◽

10.1139/p03-032 ◽

2003 ◽

Vol 81 (1-2) ◽

pp. 293-299 ◽

Cited By ~ 2

Author(s):

C Petrich ◽

T G Haskell ◽

P J Langhorne

Keyword(s):

Crystal Structure ◽

Phase Transition ◽

Sea Ice ◽

Finite Volume Method ◽

Ice Sheets ◽

First Year ◽

Two Dimensional ◽

Freezing Front ◽

Buoyancy Driven Convection ◽

Volume Method

The structure of natural refrozen cracks in landfast first-year sea ice in McMurdo Sound, Antarctica, is examined in Spring. The alignment of inclusions, crystal structure, and two-dimensional salinity profiles are discussed and compared to freezing experiments on slots cut in sea ice sheets. The investigated cracks and slots are of the order of 2030 cm wide and grown in ice of about 12.2 m thickness. Convection in the water column during the phase transition is modelled with the Finite Volume Method. We find that inclusions seem to align with the freezing front, and suggest that the crystal structure and salinity profile are influenced by buoyancy-driven convection inside refreezing cracks. PACS Nos.: 46.50+a, 62.20Mk

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