scholarly journals Mushy Layer Physics in Sea Ice Models

2021 ◽  
Author(s):  
Adrian Turner
Keyword(s):  
Sea Ice ◽  
Mushy Layer

scholarly journals Sea ice is a mushy layer

2006 ◽  
Vol 33 (14) ◽  
Author(s):  
D. L. Feltham ◽  
N. Untersteiner ◽  
J. S. Wettlaufer ◽  
M. G. Worster
Keyword(s):  
Sea Ice ◽  
Mushy Layer

scholarly journals Flow-induced morphological instability of a mushy layer

1999 ◽  
Vol 391 ◽  
pp. 337-357 ◽  
Author(s):  
DANIEL L. FELTHAM ◽  
M. GRAE WORSTER
Keyword(s):  
Shear Flow ◽  
Sea Ice ◽  
Forced Flow ◽  
Complete Analysis ◽  
Mushy Layer ◽  
The Novel ◽  
Instability Mechanism ◽  
Morphological Instability ◽  
Parallel Shear Flow ◽  
Fundamental Mechanism

A morphological instability of a mushy layer due to a forced flow in the melt is analysed. The instability is caused by flow induced in the mushy layer by Bernoulli suction at the crests of a sinusoidally perturbed mush–melt interface. The flow in the mushy layer advects heat away from crests which promotes solidification. Two linear stability analyses are presented: the fundamental mechanism for instability is elucidated by considering the case of uniform flow of an inviscid melt; a more complete analysis is then presented for the case of a parallel shear flow of a viscous melt. The novel instability mechanism we analyse here is contrasted with that investigated by Gilpin et al. (1980) and is found to be more potent for the case of newly forming sea ice.

scholarly journals Technical Note: On the use of the mushy-layer Rayleigh number for the interpretation of sea-ice-core data

2013 ◽  
Vol 7 (4) ◽  
pp. 3209-3230 ◽  
Author(s):  
M. Vancoppenolle ◽  
D. Notz ◽  
F. Vivier ◽  
J. Tison ◽  
B. Delille ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Rayleigh Number ◽  
Sea Ice ◽  
Standard Method ◽  
Ice Core ◽  
Active Regions ◽  
Technical Note ◽  
Mushy Layer ◽  
Core Data ◽  
Specific Formulation

Abstract. We examine some practical aspects of using a mushy-layer Rayleigh number for the interpretation of sea-ice-core data. In principle, such analysis should allow one to determine convectively active regions within the ice core by identifying those regions in which the mush-Rayleigh number is super-critical. In practice, however, a quantitative analysis is complicated by uncertainties regarding the specific formulation of both the mush-Rayleigh number itself and of the sea-ice permeability that is crucial for quantifying the Rayleigh number. Additionally, brine loss from highly permeable sections of the ice core, in particular close to the ice–ocean interface, and typically weekly ice core sampling, limit the practical applicability of the Rayleigh number for ice-core interpretation. We here quantify these uncertainties, suggest a standard method for the computation of the Rayleigh number for sea ice and discuss possibilities and limitations of ice-core interpretation based on the Rayleigh number.

scholarly journals Sub‐ice platelet layer physics: Insights from a mushy‐layer sea ice model

2021 ◽  
Author(s):  
P. Wongpan ◽  
M. Vancoppenolle ◽  
P.J. Langhorne ◽  
I.J. Smith ◽  
G. Madec ◽  
...  
Keyword(s):  
Sea Ice ◽  
Mushy Layer ◽  
Ice Model

scholarly journals Mushy-layer growth and convection, with application to sea ice

2019 ◽  
Vol 377 (2146) ◽  
pp. 20180165 ◽  
Author(s):  
Andrew J. Wells ◽  
Joseph R. Hitchen ◽  
James R. G. Parkinson
Keyword(s):  
Sea Ice ◽  
Layer Growth ◽  
Phase Behaviour ◽  
Salt Transport ◽  
Future Research ◽  
Mushy Layer ◽  
Convective Flows ◽  
Ice Growth ◽  
Mushy Layers ◽  
The Impact

Sea ice is a reactive porous medium of ice crystals and liquid brine, which is an example of a mushy layer. The phase behaviour of sea ice controls the evolving material properties and fluid transport through the porous ice, with consequences for ice growth, brine drainage from the ice to provide buoyancy fluxes for the polar oceans, and sea-ice biogeochemistry. We review work on the growth of mushy layers and convective flows driven by density gradients in the interstitial fluid. After introducing the fundamentals of mushy-layer theory, we discuss the effective thermal properties, including the impact of salt transport on mushy-layer growth. We present a simplified model for diffusively controlled growth of mushy layers with modest cooling versus the solutal freezing-point depression. For growth from a cold isothermal boundary, salt diffusion modifies mushy-layer growth by around 5–20% depending on the far-field temperature and salinity. We also review work on the onset, spatial localization and nonlinear development of convective flows in mushy layers, highlighting recent work on transient solidification and models of nonlinear convection with dissolved solid-free brine channels. Finally, future research opportunities are identified, motivated by geophysical observations of ice growth. This article is part of the theme issue ‘The physics and chemistry of ice: scaffolding across scales, from the viability of life to the formation of planets’.

Three-dimensional convection, phase change, and solute transport in mushy sea ice

2020 ◽  
Author(s):  
Andrew Wells ◽  
James Parkinson ◽  
Dan Martin ◽  
Richard Katz
Keyword(s):  
Sea Ice ◽  
Adaptive Mesh Refinement ◽  
Three Dimensional ◽  
Winter Season ◽  
Adaptive Mesh ◽  
Mushy Layer ◽  
Ice Growth ◽  
Buoyancy Forcing ◽  
Wide Range ◽  
Brine Rejection

<p>Sea ice is a porous mushy layer composed of ice crystals and interstitial brine. The dense brine tends to sink through the ice, driving convection. Downwelling at the edge of convective cells leads to dissolution of the ice matrix and the development of narrow, entirely liquid brine channels. The channels provide an efficient pathway for drainage of the cold, saline brine into the underlying ocean. This brine rejection provides an important buoyancy forcing for the polar oceans, and causes variation of the internal structure and properties of sea ice on seasonal and shorter timescales. This process is inherently multiscale, with simulations requiring resolution from O(mm) brine-channel scales to O(m) mushy-layer dynamic scales.</p><p> </p><p>We present new, fully 3-dimensional numerical simulations of ice formation and convective brine rejection that model flow through a reactive porous ice matrix with evolving porosity. To accurately resolve the wide range of dynamical scales, our simulations exploit Adaptive Mesh Refinement using the Chombo framework. This allows us to integrate over several months of ice growth, providing insights into mushy-layer dynamics throughout the winter season. The convective desalination of sea ice promotes increased internal solidification, and we find that convective brine drainage is restricted to a narrow porous layer at the ice-ocean interface. This layer evolves as the ice grows thicker over time. Away from this interface, stagnant sea ice consists of a network of previously active brine channels that retain higher solute concentrations than the surrounding ice. We investigate the response of ice growth and brine drainage to varying atmospheric cooling conditions, and consider the potential implications for ice-ocean brine fluxes, nutrient transport, and sea ice ecology.</p><p><br><br></p>

Natural convection during solidification of an alloy from above with application to the evolution of sea ice

1997 ◽  
Vol 344 ◽  
pp. 291-316 ◽  
Author(s):  
J. S. WETTLAUFER ◽  
M. GRAE WORSTER ◽  
HERBERT E. HUPPERT
Keyword(s):  
Sea Ice ◽  
Solid Fraction ◽  
Laboratory Experiments ◽  
Temporal Evolution ◽  
Critical Rayleigh Number ◽  
Model Systems ◽  
Laboratory Simulation ◽  
Mushy Layer ◽  
Magma Chambers ◽  
Aqueous Salt Solutions

We describe a series of laboratory experiments in which aqueous salt solutions were cooled and solidified from above. These solutions serve as model systems of metallic castings, magma chambers and sea ice. As the solutions freeze they form a matrix of ice crystals and interstitial brine, called a mushy layer. The brine initially remains confined to the mushy layer. Convection of brine from the interior of the mushy layer begins abruptly once the depth of the layer exceeds a critical value. The principal path for brine expelled from the mushy layer is through ‘brine channels’, vertical channels of essentially zero solid fraction, which are commonly observed in sea ice and metallic castings. By varying the initial and boundary conditions in the experiments, we have been able to determine the parameters controlling the critical depth of the mushy layer. The results are consistent with the hypothesis that brine expulsion is initially determined by a critical Rayleigh number for the mushy layer. The convection of salty fluid out of the mushy layer allows additional solidification within it, which increases the solid fraction. We present the first measurements of the temporal evolution of the solid fraction within a laboratory simulation of growing sea ice. We show how the additional growth of ice within the layer affects its rate of growth.

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