Arctic Sea Ice Dynamics Using Experiments and Multi-scale Modelling

Lead Research Organisation: University College London
Department Name: Earth Sciences

Abstract

Satellite and submarine observations reveal the Arctic sea ice cover is thinning at a rapid rate. Recent computer modelling shows that predictions of sea ice export into the Greenland Sea, where it will melt to form a buoyant layer weakening downwelling and hence reducing the strength of the northern extent of the Gulf Stream, are highly sensitive to the treatment of forces in the sea ice cover. The model representation of sea ice forces is uncertain, but the stresses are principally determined by sea ice floes (which are 100 m to 10 km wide and a few metres thick) overiding each other in vertical deformation to form pressure ridges and by in-plane, i.e. horizontal, frictional sliding of sea ice floes past each other. Previous experimental studies and most modelling work has focussed on the role of vertical deformation in determining ice stresses but satellite observations, derived using algorithms for feature tracking, show that almost all the deformation of sea ice is due to in-plane frictional sliding. The proposed research will combine ice tank measurements of the in-plane frictional sliding of an artificial sea ice cover with numerical simulations to give a validated model of in-plane sea ice deformation and the stresses that result. The derived model of sea ice stress will be incorporated into the sea ice model component of an Global Climate Model and its predictions compared with observations of Arctic sea ice motion, extent, concentration, and thickness. The new sea ice stress model will be made available to the Hadley Centre and other climate modelling groups. The proposed programme of research is therefore timely in both its purely scientific and technical modelling aspects.

Publications

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Bailey E (2010) A model for the consolidation of rafted sea ice in Journal of Geophysical Research

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Heorton HDBS (2018) Stress and deformation characteristics of sea ice in a high-resolution, anisotropic sea ice model. in Philosophical transactions. Series A, Mathematical, physical, and engineering sciences

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Lishman B (2011) A rate and state friction law for saline ice in Journal of Geophysical Research

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Sammonds PR (2017) Micromechanics of sea ice frictional slip from test basin scale experiments. in Philosophical transactions. Series A, Mathematical, physical, and engineering sciences

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Wilchinsky A (2010) Effect of shear rupture on aggregate scale formation in sea ice in Journal of Geophysical Research

 
Description None since the project ended.
Exploitation Route See Narrative impacts.
Sectors Aerospace, Defence and Marine,Education,Environment

 
Description The project has finished. Work from this project helped inform the development of a new anisotropic rheology, now incorporated into the sea ice climate model component CICE that is used by various modelling centres around the world, including the UK Met Office. The outcomes of this work also provided the basis for a subsequent, successful grant application to NERC on anisotropic sea ice mechanics.
First Year Of Impact 2012
Sector Aerospace, Defence and Marine,Education,Environment
 
Description Input to Arctic Select Committee of House of Lords - oral and written evidence
Geographic Reach Australia 
Policy Influence Type Gave evidence to a government review
URL http://www.parliament.uk/business/committees/committees-a-z/lords-select/arcticcom/publications/
 
Title Input to CICE sea ice climate model 
Description Research projects have developed new physics of sea ice processes. Under separate funding, but in collaboration with research projects, this has been turned into new physics modules in the sea ice climate model CICE. 
Type Of Technology Physical Model/Kit 
Year Produced 2017 
Impact The CICE sea ice model is used by climate modelling groups worldwide. In the UK this includes the UK Met Office, NOC and BAS.