Quoted from: https://www.cesm.ucar.edu/models/cesm1.2/cice/doc/node2.html 

CICE4 is the latest version of the Los Alamos Sea Ice Model, sometimes referred to as the Community Ice CodE. It is the result of a community effort to develop a portable, efficient sea ice model that can be run coupled in a global climate model or uncoupled as a stand-alone ice model. It has been released as the sea ice component of the Community Earth System Model (CESM), a fully-coupled global climate model that provides simulations of the earths past, present and future climate states. CICE4 is supported on high- and low-resolution Greenland Pole and tripole grids, which are identical to those used by the Parallel Ocean Program (POP) ocean model. The high resolution version is best suited for simulating present-day and future climate scenarios while the low resolution option is used for paleoclimate simulations and debugging. An uncoupled version of CICE is available separately from Los Alamos National Laboratory:

http://oceans11.lanl.gov/trac/CICE

It provides a means of running the sea ice model independent of the other CESM components. It reads in atmospheric and ocean forcing, which eliminates the need for the flux coupler, and the atmosphere, land and ocean data models. It can be run on a reduced number of processors, or without MPI (Message Passing Interface) for researchers without access to these computer resources.

The physics in the uncoupled ice model are identical to those in the ice model used in the fully coupled system. CICE is a dynamic-thermodynamic model that includes a subgrid-scale ice thickness distribution ((Bitz et al.(2001)); (Lipscomb(2001))). It uses the energy conserving thermodynamics of (Bitz and Lipscomb(1999)), has multiple layers in each thickness category, and accounts for the influences of brine pockets within the ice cover. The ice dynamics utilizes the elastic-viscous-plastic (EVP) rheology of (Hunke and Dukowicz(1997)). Sea ice ridging follows (Rothrock(1975)) and (Thorndike et al.(1975)). A slab ocean mixed layer model is included. A Scientific Reference is available that contains more detailed information on the model physics.

An attempt has been made throughout this document to provide the following text convention. Variable names used in the code are typewritten. Subroutine names are given in italic, and file names are in boldface.