1: Control case: F2000climo

1: Control case: F2000climo#

Exercise: Customize your CAM history files

Create, configure, build and run a case called f2000_control with the F2000climo compset (data ocean and climatological forcings from around year 2000).

Run for 5 days, with 3-hourly instantaneous output of the variables: TS, PS, Z500, U850, U200, T850, T500, T200, CLDLOW, PRECT, LHFLX, SHFLX, FLNT, FLNS. You are also welcome to output your own variables

About the resolution for F2000climo?

Supported resolution for this compset is: f09_f09_mg17 (i.e. 1 degree)
During the tutorial, we recommend to use : f19_f19_mg17 (i.e. 2 degree) because it will be faster.

Click here for hints

How do I output 3 hourly instantaneous variables?

Use namelist variables: nhtfrq, mfilt, fincl.
For more information, look at the chapter:
NAMELIST MODIFICATIONS -> Customize CAM output

What is the resolution for F2000climo?

Supported resolution for this compset is: f09_f09_mg17 (i.e. 1 degree)
During the tutorial, we recommend to use : f19_f19_mg17 (i.e. 2 degree) because it will be faster.

Click here for the solution

# Set environment variables

Set environment variables with the commands:

For tcsh users

set CASENAME=f2000_control
set CASEDIR=/glade/u/home/$USER/cases/$CASENAME
set RUNDIR=/glade/derecho/scratch/$USER/$CASENAME/run
set COMPSET=F2000climo
set RESOLUTION=f19_f19_mg17

For bash users

export CASENAME=f2000_control
export CASEDIR=/glade/u/home/$USER/cases/$CASENAME
export RUNDIR=/glade/derecho/scratch/$USER/$CASENAME/run
export COMPSET=F2000climo
export RESOLUTION=f19_f19_mg17

# Make a case directory

If needed create a directory cases into your home directory:

mkdir /glade/u/home/$USER/cases/

# Create a new case

Create a new case with the command create_newcase:

cd /glade/u/home/$USER/code/my_cesm_code/cime/scripts/
./create_newcase --case $CASEDIR --res $RESOLUTION --compset $COMPSET

# Change the job queue and account number

If needed, change job queue and account number.
For instance, to run in the queue tutorial and the project number UESM0013. You should use the project number given for this tutorial.

cd $CASEDIR
./xmlchange JOB_QUEUE=tutorial,PROJECT=UESM0013 --force

This step can be redone at anytime in the process.

# Setup

Invoke case.setup with the command:

cd $CASEDIR
./case.setup    

# Customize namelists

Edit the file user_nl_cam and add the lines:

nhtfrq(2) = -3
mfilt(2) = 240
fincl2 = 'TS:I','PS:I', 'U850:I','T850:I','PRECT:I','LHFLX:I','SHFLX:I','FLNT:I','FLNS:I'

You can do this with a text editor. Alternatively, you can use the echo command:

echo "nhtfrq(2) = -3">> user_nl_cam    
echo "mfilt(2) = 240">> user_nl_cam
echo "fincl2 = 'TS:I','PS:I', 'U850:I','T850:I','PRECT:I','LHFLX:I','SHFLX:I','FLNT:I','FLNS:I'">> user_nl_cam
echo "">> user_nl_cam    

You build the namelists with the command:

./preview_namelists

This step is optional as the script preview_namelists is automatically called by case.build and case.submit. But it is nice to check that your changes made their way into:

$CASEDIR/CaseDocs/atm_in

# Set run length

If needed, change the run length. If you want to run 5 days, you don’t have to do this, as 5 days is the default.

./xmlchange STOP_N=5,STOP_OPTION=ndays

# Build and submit:

qcmd -- ./case.build
./case.submit

# Check your solution

When the run is completed, look at the history files into the archive directory.

(1) Check that your archive directory on derecho (The path will be different on other machines):

cd /glade/derecho/scratch/$USER/archive/$CASENAME/atm/hist
ls 

As your run is only 5-day, there should be no monthly file (h0)

(2) Look at the contents of the h1 files using ncdump.

cd /glade/derecho/scratch/$USER/archive/$CASENAME/atm/hist
ncdump -h f2000_control.cam.h1.0001-01-01-00000.nc

The file should contain the instantaneous output in the file h1 for the variables:

        float FLNS(time, lat, lon) ;
                FLNS:Sampling_Sequence = "rad_lwsw" ;
                FLNS:units = "W/m2" ;
                FLNS:long_name = "Net longwave flux at surface" ;
        float FLNT(time, lat, lon) ;
                FLNT:Sampling_Sequence = "rad_lwsw" ;
                FLNT:units = "W/m2" ;
                FLNT:long_name = "Net longwave flux at top of model" ;
        float LHFLX(time, lat, lon) ;
                LHFLX:units = "W/m2" ;
                LHFLX:long_name = "Surface latent heat flux" ;
        float PRECT(time, lat, lon) ;
                PRECT:units = "m/s" ;
                PRECT:long_name = "Total (convective and large-scale) precipitation rate (liq + ice)" ;
        float PS(time, lat, lon) ;
                PS:units = "Pa" ;
                PS:long_name = "Surface pressure" ;
        float SHFLX(time, lat, lon) ;
                SHFLX:units = "W/m2" ;
                SHFLX:long_name = "Surface sensible heat flux" ;
        float T850(time, lat, lon) ;
                T850:units = "K" ;
                T850:long_name = "Temperature at 850 mbar pressure surface" ;
        float TS(time, lat, lon) ;
                TS:units = "K" ;
                TS:long_name = "Surface temperature (radiative)" ;
        float U850(time, lat, lon) ;
                U850:units = "m/s" ;
                U850:long_name = "Zonal wind at 850 mbar pressure surface" ;

Note that these variables have no cell_methods attribute becasue the output is instantaneous.