Ice forcing files
Forcing files required for the sea ice model (CICE) are the ocean grid and the ocean bathymetry. A requirement in CESM1 is that the ocean and sea ice model components share the same grid, which is an irregular POP dipole grid; deep time modelers typically use a nominally 3o ocean/ice grid.
Ice initial conditions
Ice initial conditions files are not required for deep time paleoclimate cases. We recommend initializing the ice model with a ‘no ice’ initial state and allowing the model to simulate an ice state. Set ‘no ice’ in the ice model namelist, called csim.buildnml_prestage.csh:
set no_ice_ic = .false.