Scheduled Downtime
On Tuesday 24 October 2023 @ 5pm MT the forums will be in read only mode in preparation for the downtime. On Wednesday 25 October 2023 @ 5am MT, this website will be down for maintenance and expected to return online later in the morning.
Normal Operations
The forums are back online with normal operations. If you notice any issues or errors related to the forums, please reach out to help@ucar.edu

4 months short experiments with CAM4 and spinup issue

Hi Everyone,

I am using CAM4 for short term seasonal forecast. Each of my expimrent is four months long. I initialize model from the Intial condition prepared by DART-CAM data assimilation system. For all cases (for exapmle, 2000 May experiment) I start CAM4 from 20000501 and run for 4 months. I provide the DART-CAM atomospheric and land initial conditions (as shown in the script below). I keep the SST and sea ice persistant (by adding observe SST anomaly of April to SST climatology file) and keep the sstcycle=.true. Model runs perfectly and gives output in monthly and daily format. I compare the output with observation then. In this process, I am confuse about the following two issues.

1 :- Do I need to run model for some spinup time before using them in forecast mode? I tried to run the model for 6 month and then from the last restart file, I run the model again with my initial condition but It seems that this may not be the way. If the model starts from the restart files, then how can I add information of my intial condition in that restart time?

2:- Along with atomospheric and land initial conditions I also have cice model initial condition, but I donot know how to include the ice model initial condition in my experiment. Do I realy need it if I keep the sea ice persistant?

3:- and the last issue is about the orbit year. Is there any significant effect if I donot chnage it from the default value?

I will appricaite if some one can help me to sort out these issues. I tried to find information on this form but these is no previous post. The script I am using for such experiments is as following.

============================
#! /bin/csh -f

echo " I am starting for May 2000 with presistance SST and sea ice ..."

limit stacksize unlimited

set netcdf = /global/software/netcdf/netcdf-4.1.3
set mpich = /global/software/intel2012/impi/4.0.3.008/intel64

setenv P4_GLOBMEMSIZE 500000000
setenv OMP_NUM_THREADS 1
setenv INC_NETCDF ${netcdf}/include
setenv LIB_NETCDF ${netcdf}/lib
setenv INC_MPI ${mpich}/include
setenv LIB_MPI ${mpich}/lib
setenv CSMDATA /global/scratch/siraj/inputdata
setenv LID "`date +%y%m%d-%H%M%S`"

set cfg_string = "-fc ifort "
set camroot = /home/siraj/ccsm4
set version = "cam4"
set dycore = "fv"
set caseid = 2000_May
set hgrid = "1.9x2.5"
set ntask = 16
set case = ${dycore}${hgrid}_${caseid}
set wrkdir = /global/scratch/siraj/dsp
set blddir = $wrkdir/$case/bld
set rundir = $wrkdir/$case
set cfgdir = $camroot/models/atm/cam/bld
set archdir = $camroot/scripts/ccsm_utils/Tools/archiving

echo " I am building now and will take some time at this step :) ..."
mkdir -p $rundir || echo "cannot create $rundir" && exit 1
mkdir -p $blddir || echo "cannot create $blddir" && exit 1

if ( ! -x $blddir/cam ) then
cd $blddir
$cfgdir/configure $cfg_string -phys $version -v -test -dyn $dycore -hgrid $hgrid -spmd -nosmp -linker mpif90 -ntasks $ntask || echo "configure failed" && exit 1
echo "building CAM in $blddir ..."
rm -f Depends
gmake -j 4 >&! MAKE.out || echo "CAM build failed: see $blddir/MAKE.out" && exit 1
endif

cd $blddir || echo "cd $blddir failed" && exit 1
echo " Now I am building the namelist..."
$cfgdir/build-namelist -test -case $case
-config $blddir/config_cache.xml
-ignore_ic_date
-namelist "&camexp start_type='startup' start_ymd=20000501 stop_ymd=20000901
stop_option='nmonths' stop_n=5 restart_option='none' inithist='NONE' nhtfrq=0,-24 ndens=2 mfilt=1,10 hist_empty_htapes=.true. empty_htapes=.true. sstcyc=.true.
fincl1='TS:A','PRECT:A','PS:A','U:A','V:A','T:A','Q:A','RELHUM:A','Z3:A','T850: A','U200:A','U850:A','V200:A','V850:A','Z500:A'
fincl2='T850:A','PRECT:A'
ncdata ='$CSMDATA/Jun_pertub_ics/cam_initial_day01_00Z_2000_May_e1.nc'
finidat ='$CSMDATA/2000/May/clm_initial_day01_00Z.nc'
bndtvs='$CSMDATA/sst_final_data1/sst_HadOIBl_bc_1.9x2.5_clim_c061031_2000_May.nc' /"
echo "build-namelist done and I am ready to run using qsub"
echo "Now check my bld directory and submitt the job using qsub"

## Run CAM creating run script in $rundir
cat >! $rundir/$case-run.csh &! cam.log.$LID || echo "CAM run failed" && exit 1
wait
echo "`date` -- $version execution script""
EOF
chmod +x $rundir/$case-run.csh
# END
exit 0
 
Top