Either use the
xmlchange function or open the env_run.xml and edit directly to alter:
These are by default
RUN_STARTDATE = 2005-01-01,
STOP_OPTION = ndays, and
STOP_N = 5, the recommended "out-of-the-box" test set-up.
RUN_STARTDATE has format YYYY-MM-DD. *** Be sure to change the meteorological forcing files used and that emissions cover the dates specified***.
STOP_OPTION has many options including ndays, nmonths, or nyears (see
env_run.xml for more options).
STOP_N will stop after the specified number of
STOP_OPTION increments. For example the default:
will stop simulations after 5 days. Depending on your set-up and computational resources, it is usually recommended to run 6 to 12 months at a time, after testing phase with 5-days is complete and the experimental runs are begun.
You will also need to point to initialization files by updating the path by adding the following to
as well as the land initialization in
Initialization files are written out from a previous run and specify initial states of chemical fields, instead of spinning up from zero. Another option is to use the default initialization file, perform a one-year spin up and re-initialize with the output from that simulation to minimize the initial condition influence.
Some initialization files can be found on Cheyenne mass storage system (HPSS):
Every year from 1993-2015: /home/buchholz/CESM206_CAMchem_longrun_fmerra_branchbase
Every year from 1975-1993: /home/buchholz/CESM206_CAMchem_longrun_fmerra
We will have a set of publicly available initialization files soon. For now, either access from Cheyenne HPSS or contact someone in the CAM-chem team if you wish to use something other than the default file.