Exercise 2#
Create a case called b1850_high_freq
using the compset B1850-tutorial
at f19_g17
resolution.
In addition to the monthly history file h0
, add the following output:
an
h1
file with daily averages ofTREFHT
andPRECT
an
h2
file with instantaneous values ofPSL
andU10
every 6 hours.
Set your namelist so that you output:
a single
h1
file with all the daily averaged output for the 5 day run.multiple
h2
files, one for each day i.e., containing four 6 hourly time values.
Your goal is to produce:
one
h1
file with 5 timesteps andfive
h2
files with 4 timesteps each.
Use the default 5-day run length and make a 5-day run
Click here for hints
# How do I control the output?
Use namelist variables: nhtfrq
, mfilt
, fincl
.
Look at the online documentation for these variables.
# Check your setting
Check in the CaseDocs
directory. Is your atm_in
file correct? Does it contain the namelist
additions you made? What about the file atm_in
in your run
directory?
You should find that the changes you have made have propagated to all the atm_in files.
If you would like to propagate the changes to the atm in files without building you can also run the command
./preview namelists.
# Check when it is running
Is it running successfully and producing the extra history files? One way to check is to go to the run directory as it is running and see whether the history files are arriving. Once it has finished, do you see the history files in the archive directory? How many time values are in each file? Does it make sense?
When your run is completed, go to the archive directory and navigate to the subdirectory atm/hist
cd ~/scratch/archive/b1850_high_freq
cd atm/hist
What files are in this directory?
Click here for the solution
# go into scripts directory into the CESM code
cd $CESMROOT/cime/scripts
# Create a new case
Create a new case b1850_high_freq
with the command:
./create_newcase --case ~/cases/b1850_high_freq --compset B1850-tutorial --res f19_g17
# go into the case you just created in the last step
cd ~/cases/b1850_high_freq
# Setup
Invoke case.setup with the command:
./case.setup
# Customize namelists
Edit the file user_nl_cam
and add the lines:
fincl2='TREFHT','PRECT'
fincl3='PSL:I','U10:I'
nhtfrq=0,-24,-6
mfilt =1,5,4
# Build and submit
Build the model and submit your job:
qcmd -- ./case.build
./case.submit
# Look at your solution
When the run is completed, look into the archive directory for:
b1850_high_freq
.
(1) Check the contents of your archive directory:
cd ~/scratch/archive/b1850_high_freq/atm/hist
ls
(2) Compare the contents of the h1
and h2
files using ncdump
.
Look at the variables attributes. What is the difference between the 2 files ?