Running with your own previous simulation as atmospheric forcing to spinup the model

Another way that you might want to spinup the model is to run your own simulation for a relatively short period (either a B, E, or F compset) and then use it as forcing for your "I" case later. By only running 20 to 50 years for the fully coupled case, you'll save a substantial amount of computer time rather than running the entire spinup period with a fully coupled model.

The first thing we need to do is to run a fully coupled case and save the atmospheric coupling fields on a three hourly basis. In this example, we will run on bluefire and archive the data to a local disk that we can then use in the next simulation.

Example 4-8. Example Fully Coupled Simulation to Create Data to Force Next Example Simulation

> cd scripts
> ./create_newcase -case myBCN1850 -res f09_g16 -compset B1850CN  -mach bluefire
> cd myBCN1850
> ./configure -case
# Set histaux_a2x3hr to .true. in cpl.buildnml.csh so output from the atmosphere model 
# will be saved 3 hourly
$EDITOR BuildConf/cpl.buildnml.csh
# Now build
> ./
# The following sets the archival disk space (you could also use an editor)
> ./xmlchange -file env_run.xml -id DOUT_S_ROOT -val '/glade/home/$USER/$CASE'
# Make sure files are archived to disk, but NOT to long term storage 
# (you could also use an editor)
> ./xmlchange -file env_run.xml -id DOUT_S -val TRUE
> ./xmlchange -file env_run.xml -id DOUT_L_MS -val FALSE
# Set the run length to run a total of 20 years (you could also use an editor)
> ./xmlchange -file env_run.xml -id RESUBMIT -val 9
> ./xmlchange -file env_run.xml -id STOP_OPTION -val nyears
> ./xmlchange -file env_run.xml -id STOP_N -val 2
# Now run as normal
> ./myBCN1850.bluefire.submit

Now we run an I compset forced with the data from the previous simulation using the CPLHIST3HrWx option to DATM_MODE. See the Section called CPLHIST3HrWx mode and it's DATM settings in Chapter 1 for more information on the DATM settings for CPLHIST3HrWx mode.

Example 4-9. Example Simulation Forced with Data from the Previous Simulation

> cd scripts
> ./create_newcase -case frcwmyBCN1850 -res f09_g16 -compset I1850SPINUPCN -mach bluefire
> cd frcWmyBCN1850
# The following sets the casename to point to for atm forcing (you could also use an editor)
> ./xmlchange -file env_conf.xml -id DATM_CPL_CASE -val "myBCN1850"
# The following sets the align year and years to run over for atm forcing 
#  (you could also use an editor)
> ./xmlchange -file env_conf.xml -id DATM_CPL_YR_ALIGN -val "1"
> ./xmlchange -file env_conf.xml -id DATM_CPL_YR_START -val "1"
> ./xmlchange -file env_conf.xml -id DATM_CPL_YR_END -val "20"
# Set the datapath in the template to the archival path from the case above
> sed -E 's#set datapath = ".+"#set datapath = "/glade/home/$USER/%c/cpl/hist"#' \
  Tools/Templates/datm.cpl7.template > new.datm.cpl7.template
> mv -f new.datm.cpl7.template Tools/Templates/datm.cpl7.template
> chmod +x Tools/Templates/datm.cpl7.template 
> ./configure -case
# Now build and run as normal
> ./
> ./frcwmyBCN1850.bluefire.submit

Note: In order to accomplish this we needed to edit the DATM template file. See Appendix A for more information on doing this. If your input case was at a resolution besides f09 you would have to edit the DATM template file even further to use a domain file at the input resolution.