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SUMMARY:Effective Rheology and Wave Propagation in the Marginal Ice Zone -
  Christian Samspon (University of Utah\; UNC Chapel Hill and RIMS)
DTSTART:20170912T133000Z
DTEND:20170912T140000Z
UID:TALK78961@talks.cam.ac.uk
CONTACT:INI IT
DESCRIPTION:<span>Co-authors: Ken Golden		(University of Utah)\, Ben Murph
 y		(University of Utah)\, Elena Cherkaev		(University of Utah)        <br>
 </span><span><br>Wave-ice interactions in the polar oceans comprise a comp
 lex but important set of processes influencing sea ice extent\, ice pack a
 lbedo\, and ice thickness. In both the Arctic and Antarctic\, the ice floe
  size distribution in the Marginal Ice Zone (MIZ) plays a central role in 
 the properties of wave propagation. Ocean waves break up and shape the ice
  floes which\, in turn\, attenuate various wave characteristics. Recently\
 , continuum models have been developed which treat the MIZ as a two-compon
 ent composite of ice and slushy water. The top layer has been taken to be 
 purely elastic\, purely viscous or viscoelastic. At the heart of these mod
 els are effective parameters\, namely\, the effective elasticity\, viscosi
 ty\, and complex viscoelasticity. In practice\, these effective parameters
 \, which depend on the composite geometry and the physical properties of t
 he constituents\, are quite difficult to determine. To help overcome this 
 limitation\, we employ the methods of homogenization theory\, in a quasist
 atic\, fixed frequency regime\, to find a Stieltjes integral representatio
 n for the complex viscoelasticity. </span>This integral representation inv
 olves the spectral measure of a self adjoint operator and provides what we
  believe are the first rigorous bounds on the effective viscoelasticity of
  the sea ice pack. The bounds themselves depend on the moments of the meas
 ure which in turn depend on the geometry of the ice floe configurations. T
 his work has the potential to provide simple parameterizations of wave pro
 perties which take into account floe concentration and geometry. <br>
LOCATION:Seminar Room 1\, Newton Institute
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