CCSM3.0 Paleo UG | Ocean Initial Condition

There are four options for defining initial ocean/ice conditions for startup runs. The choices include, mean, zonal-mean, startup (default), and internal. Details on how to invoke each choice are discussed in the model build scripts section.

startup (default configuration)

Initialize with a full spatially distributed temperature/salinity dataset

If the modeler has latitude, longitude, and depth information on temperature and salinity, the ocean model can be initialized in the default configuration with a binary file at startup. This is recommended only if the modeler has this information on an appropriate grid or a grid that is close enough for interpolation. We provide a sample NCL script that will interpolate initial T/S information between two similar grids. This option will be more appropriate for near-modern cases


Initialize with a global, zonally averaged temperature/salinity distribution.

POP allows a zonally averaged temperature/salinity file to be used for initialization. This file is binary and the format can be found in the CCSM3/POP source code, subroutine initial.F


Initialize with a global, horizontally averaged temperature/salinity depth profileInitializing with a global volume averaged temperature profile is the recommended method for deep time paleo simulations. Often, very little information on deep ocean temperatures is known, so initializing with a simple depth profile is the easiest method.

POP requires this initial file to be a simple ASCII file with a temperature and salinity value for each vertical level.  See the example ASCII file in setup_tools and shown in Figure X.


Initialize with the default Levitus temperature/salinity profile.

Present day temperature and salinity profiles can be computed internally at runtime based on 1992 Levitus data.