HR: 11:50h
AN: C22A-07    [Abstracts]
TI: Simulations of sea ice lead formation and evolution
AU: * Coon, M
EM: max@nwra.com
AF: NorthWest Research Associates, 14508 NE 20th Street, Bellevue, WA 98007, United States
AU: Sulsky, D
EM: sulsky@math.unm.edu
AF: University of New Mexico, Department of Mathematics and Statistics Office: 472 Humanities Building, Albuquerque, NM 87131, United States
AU: Kwok, R
EM: ron.kwok@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109, United States
AU: Pruis, M
EM: matt@nwra.com
AF: NorthWest Research Associates, 14508 NE 20th Street, Bellevue, WA 98007, United States
AB: Our team has developed a new sea ice model which accounts for lead formation and deformation explicitly. This model will account directly for the evolution of that part of the mass balance resulting from the mechanical redistribution of ice in leads. We show results from our first simulation of the Beaufort Sea for 28 days 52-70 (February/March) in 2004. The numerical simulation was done using the material-point method with an elastic- decohesive constitutive model for sea ice. In the simulation, land is represented by material points that are treated as rigid and a no slip boundary condition is used between land and ice. Observed displacements from the RGPS data are used to prescribe the motion along the portion of the computational region that intersects the ocean, also. The simulation was forced with 6 hour NCEP winds on a 10 km grid. Earlier simulations on a smaller region of the Beaufort Sea showed that for these 16-day simulations some initialization of the ice conditions is required to reproduce the observed deformations in detail. Not surprisingly, the ice is too strong and does not deform appropriately in 16 days if we start from a homogeneous state of intact ice. Thus, we use RGPS observations from day 53.6-54.7 to determine the location and extent of some of the larger existing leads and use these observations to initialize a simulation that begins on day 54 and runs through day 70. The leads in the simulation can be compared visually with the leads from RGPS. Observations and simulations are not exactly the same. Nevertheless, we can see that reasonable looking lead patterns are produced in the simulation. This first simulation with the elastic-decohesive model shows great potential for reproducing observed pack ice dynamics.
DE: 0750 Sea ice (4540)
DE: 0754 Leads (4540)
DE: 0762 Mass balance (1218, 1223)
DE: 0774 Dynamics
DE: 0798 Modeling
SC: Cryosphere [C]
MN: 2007 Fall Meeting