HR: 0830h
AN: NG51A-0829    [PDF]
TI: Thickness distribution scaling in large scale sea ice mechanics
AU: * Roberts, A
EM: andrew.roberts@utas.edu.au
AF: University of Tasmania, Sandy Bay, Hobart, TAS 7001 Australia
AU: * Roberts, A
EM: andrew.roberts@utas.edu.au
AF: Antarctic Climate and Ecosystems Cooperative Research Centre, Private Bag 80, Hobart, Tas 7001 Australia
AU: Hughes, R
AF: The University of Melbourne, Parkville, Melbourne, Vic 3010 Australia
AU: Heil, P
AF: University of Tasmania, Sandy Bay, Hobart, TAS 7001 Australia
AU: Budd, W F
EM: w.f.budd@utas.edu.au
AF: University of Tasmania, Sandy Bay, Hobart, TAS 7001 Australia
AB: This research builds on recent advances in large scale sea ice modelling that account for quasi-fractal oriented fractures in sea ice. It investigates the possibility that some mechanical features of sea ice also scale with its thickness. It is suggested geophysical scale strain rates in sea ice may obey a law that derives from scaling internal stress with the thickness of individual floes. Results from invariant analysis of established sea ice mechanics laws, together with model simulations over the Southern Ocean suggest that scaling of internal stress with thickness is very weak. However an unexpected outcome of the analysis shows that even very weak scaling produces strain rates that vary strongly through the thickness spectrum of sea ice thickness distributions. Whilst this result is interesting in its own right, it has direct practical application in short term forecasting and assimilation using multiple thickness models. Details are provided of the scaling parameterisation as it may be applied to both medium range sea ice forecast models and coupled climate model sea ice components alike. Model results are presented that demonstrate this scheme can be used to reproduce observed features of the Southern Ocean sea ice zone.
DE: 4540 Ice mechanics and air/sea/ice exchange processes
SC: Nonlinear Geophysics [NG]
MN: 2003 Fall Meeting