CLM3 does not require an initial condition file and can be initialized with arbitrary initialization and the surface dataset created from your mksrf datafiles [finidat = ‘ ‘][fsurdat = ‘ ‘]
You can also branch from an existing simulation, using clm2.i or clm2.r files to initialize your new experiment.
However, if you have changed your land cover in your new simulation (for example, if you have changed your land ice distribution), you will first need to create a new clm2.i file that conforms to your new land cover assignments. Creating a new clm2.i file is a two step process:
1. run a 5 day startup simulation with arbitrary initialization to create a new surface dataset and clm.i file (finidat = ‘ ‘; hist_crtinic = 'DAILY')
2. re-map the land properties from the old clm2.i file, onto your new clm2.i file using interpinic.
3. Save the surface dataset created by the 5 day run for your new experiment.
The new clm2.i file produced by the 5-day startup run has landunit vector lengths consistent with the new surface dataset, but different from the original experiment that you wish to branch from. Use the tool, interpinic, to project the spun-up data from the initial clm2.i file onto the new initial file created by the 5-day startup run.
- Tool: interpinic
- Source: CCSM3_source/models/lnd/clm2/tools/interpinic
Interpinic maps land use data from one clm initial file (clm2.i; the input file) to another clm initial file (the output file) by overwriting the contents of the output file. The input and output files may be of any spatial resolution and gridcell/landunit/column/pft configuration.
Usage: interpinic -i old.clm2.i.nc -o new.clm2.i.nc