User:Sagredo/PIOMAS

PIOMAS is the Pan-Arctic Ice-Ocean Modeling and Assimilation System which was developed at the Polar Science Center, University of Washington.

The sea-ice data are assimilated by the Pan-Arctic Ice-Ocean Modeling and Assimilation System (PIOMAS) developed at the Polar Science Center, University of Washington (see Zhang and Rothrock [2001, 2003, 2005]). The PIOMAS is a coupled parallel ocean and sea-ice model with capabilities of assimilating sea ice concentration. It consists of the thickness and enthalpy distribution (TED) sea-ice model developed by Zhang and Rothrock [2001, 2003] and the Parallel Ocean Program (POP) developed at the Los Alamos National Laboratory. The TED sea-ice model is a dynamic thermodynamic model that also explicitly simulates sea-ice ridging. It has 12 categories each for ice thickness, ice enthalpy, and snow. The model employs a teardrop viscous-plastic ice rheology that determines the relationship between ice internal stress and ice deformation (see Zhang and Rothrock [2005]), a mechanical redistribution function that determines ice ridging (see Thorndike et al. [1975], Rothrock [1979], Hibler, [1980]) and an efficient numerical method to solve the ice motion equation [Zhang and Hibler,1997]). Assimilation of sea ice concentration data from satellites in PIOMAS is based on an assimilation procedure [Lindsay and Zhang, 2006] that "nudges" the model estimate of ice concentration toward the observed concentration in a manner that emphasizes the ice extent and minimizes the effect of observational errors in the interior of the ice pack. This is a relatively simple yet effective assimilation scheme that is computationally affordable for long-term integrations and experiments. In addition to improving the simulated ice edge, comparisons to observed ice thickness measurements in the Arctic indicate that the assimilation of ice data also improves the simulated ice motion and thickness.