CICE uses the same namelists for both the coupled and uncoupled models.
This section describes the namelist variables in the namelist ice_nml,
which determine time management, output frequency, model physics, and filenames
Note that as of cesm1.1, the CICE namelist can only
be modified via the $CASE/user_nl_cice file. A table of all namelist
variables is available at:
A script reads the input namelist at runtime, and writes the namelist information to the file ice_in in the directory where the model executable is located. Therefore, the namelist will be updated even if the ice model is not recompiled. The default values of the ice setup, grid, tracer, and physics namelists are set in ice_init.F90. The prescribed ice option along with the history namelist variables are set in ice_prescribed.F90 and ice_history.F90 respectively. If they are not set in the namelist in the script, they will assume the default values listed in Tables 1-7, which list all available namelist parameters. The default values shown here are for the coupled model, which is set up for a production run. Only a few of these variables are required to be set in the namelist; these values are noted in the paragraphs below. An example of the default namelist is shown in Section 3.8.1.
Varible | Type | Default Value | Description |
ice_ic |
character | default | Filename for initial and branch runs |
'default' uses default initialization | |||
'none' initializes with no ice | |||
xndt_dyn | Integer | 1 | Times to loop through (sub-cycle) ice dynamics |
diagfreq | Integer | 24 | Frequency of diagnostics written (min, max, hemispheric sums) to standard output |
24 =>
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1 =>
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0 =>
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histfreq | Character Array | 'm','x','x','x','x' | Frequency of output written to history streams |
'H' or 'h' writes hourly data | |||
'D' or 'd' writes daily data | |||
'M' or 'm' writes monthly data | |||
'Y' or 'y' writes yearly data | |||
'1' writes every timestep | |||
'x' no history data is written | |||
histfreq_n | Integer | 1,1,1,1,1 | Frequency history data is written to each stream |
hist_avg | Logical | .true. | If true, averaged history information is written out at a frequency determined by histfreq. If false, instantaneous values rather than time-averages are written. |
pointer_file | Character | 'rpointer.ice' | Pointer file that contains the name of the restart file. |
lcdf64 | Logical | .false. | Use 64-bit offset in netcdf files |
The main run management namelist options are shown in Table
1. While additional namelist variables are available in
the uncoupled version, they are set by the driver in CESM. Variables set by
the driver include: dt, runid, runtype, istep0,
days_per_year, restart and dumpfreq. These should be
changed in the CESM configuration files: