1. Running CESM An overview
Cecile Hannay, CAM Science Liaison Atmospheric Modeling and Predictability Section
Climate and Global Dynamics Division

2. Outline Overview of model capabilities The 4 steps to run CESM
Options at each step
Post-processing tools
CESM webpages

3. Community Earth System Model (CESM)
CESM is a coupled climate model
for simulating Earth’s climate system.
Composed of 5 separate models
plus one central coupler
Allows research into the Earth’s past,
present, and future climate.
Atmosphere
Land-ice
Sea-ice
Coupler
land
Ocean

4. Capabilities: components settings
CESM offers countless possibilities:
Supports several components configurations
Atmosphere
Sea-ice
Land-ice
Ocean
land
Coupler
Fully coupled model
Atmosphere and land model only
OceanObs
Sea-ice
Obs
Land-ice
land
Coupler
Ocean
Atmosphere
OceanObs
Sea-ice
Obs

5. Capabilities: platforms
CESM offers countless possibilities:
Supports several components configurations
Run on several platforms
IBM Power Ex: Bluefire (NCAR, Colorado)
Linux Box Ex: Brutus (ETH, Zurich)
Cray XT Ex: Jaguar (Oak Ridge, Tennesse)

6. Capabilities: grid / resolution
Latitude-longitude grid
CESM offers countless possibilities:
Support several components configurations
Run on several platforms
Supports several grid types and resolution
Cubed sphere grid
Range of resolution 1°
0.25°

7. Running CESM Very complex: total of 1 500 000 of lines of code
Very easy to use: can be run with 4 commands !!!!
# (1) create a new case
create_newcase –case ~case01 -res T31_g37 -compset B_1850 -mach ekman
# (2) configure the case
configure -case
# (3) build the executable
./case01.ekman.build
# (4) submit the run to the batch queue
esubmit -n 8 -t 30 ./case01.ekman.run
This is that simple !

8. CESM code and data the CESM code the CESM data
CESM is available through a subversion repository that contains
CESM should be downloaded into 2 directories
CESM code
CESM data
atm
lnd
ocn
ice
glc
inputdata
cpl
scripts
create_newcase
models
drv
utils
csm share
cesm1_0_3
Ideally these directories are shared by a group of users to save disc space. This is especially important for the inputdata directory (~ 1 Tbyte).

9. Outline Overview of model capabilities The 4 steps to run CESM
Options at each step
Post-processing tools
CESM webpages

10. The 4 steps to run CESM Step 1: create a new case Step 2: configure
Step 3: build the executable
Step 4: run CESM

11. experiment identifier
Step 1: create_newcase
CESM code
CESM data
atm
lnd
ocn
ice
glc
inputdata
cpl
scripts
create_newcase
models
drv
utils
csm share
cesm1_0_3
The first step to create a CESM experiment is to use create_newcase
create_newcase has 4 required arguments (+ more optional arguments)
create_newcase -case myFirstCase -mach ekman -compset B1850 -res 0.9x1.25_gx1v6
casename
it is the
experiment identifier
Atm
ice
glc
ocn
lnd
cpl

12. Step 1: create_newcase => result
CESM code
scripts
create_newcase
atm
lnd
ocn
ice
glc
models
drv
utils
csm share
cesm1_0_3
CESM data
atm
lnd
ocn
ice
glc
inputdata
cpl
Case directory
SourceMods
myFirstCase
configure
Tools
The result of the command
create_newcase is to
create a case directory
It contains the files necessary
for the second step: configure the model.

13. The 4 steps to run CESM Step 1: create a new case Step 2: configure
Step 3: build the executable
Step 4: run CESM

14. Step 2: Configure the case
CESM code
scripts
create_newcase
atm
lnd
ocn
ice
glc
models
drv
utils
csm share
cesm1_0_3
CESM data
atm
lnd
ocn
ice
glc
inputdata
cpl
Case directory
The next step is to configure the case.
This is done with the command
The command build all the scripts
necessary to build and run the model
SourceMods
myFirstCase
configure
Tools
configure -case

15. Step 2: Result of “configure –case”
CESM code
scripts
create_newcase
atm
lnd
ocn
ice
glc
models
drv
utils
csm share
cesm1_0_3
CESM data
atm
lnd
ocn
ice
glc
inputdata
cpl
Case directory
The next step is to configure the case.
This is done with the command
The command build all the scripts
necessary to build and run the model
(all the files in green)
myFirstCase
configure
myFirstCase.ekman.build
myFirstCase.ekman.run
SourceMods
Tools
BuildConf
*.buildnml.csh
*.buildexe.csh
*.input_data.list
configure -case

16. The 4 steps to run CESM Step 1: create a new case Step 2: configure
Step 3: build the executable
Step 4: run CESM

17. myFirstCase.ekman.build
Step 3: Building a case
CESM code
scripts
create_newcase
atm
lnd
ocn
ice
glc
models
drv
utils
csm share
cesm1_0_3
CESM data
atm
lnd
ocn
ice
glc
inputdata
cpl
Case directory
The next step is to build the model executable.
This is done with the command
The command create a run directory with everything you need to run the model (executable, namelists, …)
myFirstCase
configure
myFirstCase.ekman.build
myFirstCase.ekman.run
SourceMods
Tools
BuildConf
*.buildnml.csh
*.buildexe.csh
*.input_data.list
myFirstCase.ekman.build

18. myFirstCase.ekman.build
Step 3: Result of *.build
CESM code
scripts
create_newcase
atm
lnd
ocn
ice
glc
models
drv
utils
csm share
cesm1_0_3
CESM data
atm
lnd
ocn
ice
glc
inputdata
cpl
Build/Run directory
atm
lnd
ocn
ice
glc
myFirstCase
cpl
ccsm
run
ccsm.exe
atm_in
lnd_in
ice_in
ocn_in
drv_in
Executable
Namelists
contains everything you need
to run the model
Case directory
myFirstCase
configure
myFirstCase.ekman.build
myFirstCase.ekman.run
SourceMods
Tools
BuildConf
*.buildnml.csh
*.buildexe.csh
*.input_data.list

19. The 4 steps to run CESM Step 1: create a new case Step 2: configure
Step 3: build the executable
Step 4: run CESM

20. myFirstCase.ekman.build
Step 4: Running CESM
CESM code
scripts
create_newcase
atm
lnd
ocn
ice
glc
models
drv
utils
csm share
cesm1_0_3
CESM data
atm
lnd
ocn
ice
glc
inputdata
cpl
Case directory
Build/Run directory
myFirstCase
configure
myFirstCase.ekman.build
myFirstCase.ekman.run
SourceMods
Tools
BuildConf
*.buildnml.csh
*.buildexe.csh
*.input_data.list
myFirstCase
atm
lnd
ocn
ice
glc
cpl
ccsm
run
ccsm.exe
atm_in
lnd_in
ice_in
ocn_in
drv_in
You are ready to start your run. This is done with the command
esubmit myFirstCase.ekman.run

21. Step 4: Result of esubmit *.run
CESM code
scripts
create_newcase
atm
lnd
ocn
ice
glc
models
drv
utils
csm share
cesm1_0_3
CESM data
atm
lnd
ocn
ice
glc
inputdata
cpl
Create output files and log files
(in green)
Case directory
Build/Run directory
myFirstCase
configure
myFirstCase.ekman.build
myFirstCase.ekman.run
SourceMods
Tools
BuildConf
*.buildnml.csh
*.buildexe.csh
*.input_data.list
myFirstCase
atm
lnd
ocn
ice
glc
cpl
ccsm
run
ccsm.exe
atm_in
lnd_in
ice_in
ocn_in
drv_in
*cam2.h0*.nc
*.log.*
*.timing.*

22. Step 4: Archiving at the end of the run
CESM code
scripts
create_newcase
atm
lnd
ocn
ice
glc
models
drv
utils
csm share
cesm1_0_3
CESM data
atm
lnd
ocn
ice
glc
inputdata
cpl
Archiving output files and log files at the end of the run
Case directory
Build/Run directory
Short term
archive
directory
myFirstCase
configure
myFirstCase.ekman.build
myFirstCase.ekman.run
SourceMods
Tools
BuildConf
*.buildnml.csh
*.buildexe.csh
*.input_data.list
myFirstCase
atm
lnd
ocn
ice
glc
cpl
ccsm
run
ccsm.exe
atm_in
lnd_in
ice_in
ocn_in
drv_in
*cam2.h0*.nc
*.log.*
*.timing.*
Long term
archive
HPSS

23. The 4 steps to run CESM Step 1: create a new case Step 2: configure
Step 3: build the executable
Step 4: run CESM
This is the most basic way to run CESM. There are gazillions of possibilities to customize your experiment.

24. Outline Overview of model capabilities The 4 steps to run CESM
Options at each step
Post-processing tools
CESM webpages

25. create_newcase options (step 1)
create_newcase -case myFirstCase -mach ekman -res 0.9x1.25_gx1v6 -compset B1850
create_newcase has 4 required arguments
Atm
ice
glc
ocn
lnd
cpl
casename
it is the
experiment identifier
specifies the model resolutions
Format is : [atm/lnd grid]_[ocn/ice grid]
Ex:
name (shortname)
T31_gx3v7 (T31_g37)
0.9x1.25_gx1v6 (f09_g16)

26. create_newcase options (step 1)
create_newcase -case myFirstCase -mach ekman -res 0.9x1.25_gx1v6 -compset B1850
create_newcase has 4 required arguments
Atm
ice
glc
ocn
lnd
cpl
casename
it is the
experiment identifier
More about “compset” = component sets
B_2000
B_1850
B_1850_CAM5
F_2000_CN F_ _CN

27. Compset = component set
DATA
ACTIVE
Color code
Compset = component set
All active components
Active atmosphere/land
Atmosphere
Sea-ice
Ocean
land
Coupler
Atmosphere
Sea-ice
Ocean
land
Coupler B F
Active land
Active ocean/sea-ice
Atmosphere
Sea-ice
Ocean
land
Coupler I G

28. Configure options (step 2)
Case directory
myFirstCase
Configure
env_conf.xml
SourceMods
Tools
BuildConf
Configure options are set in: env_conf.xml
before invoking configure command
Allow to change the namelists (*_NAMELIST_OPTS)
- Ex: Used to customize your output files (Ex: monthly => 3-hour means)
(NB: There are several ways to change namelists)
Allow to change the run type => defines initial conditions (RUN_TYPE = start-up, branch, hybrid)

29. Build options (step 3) Build options are set in: env_build.xml
Case directory
myFirstCase
Configure
env_build.xml
SourceMods
Tools
BuildConf
Build options are set in: env_build.xml
before invoking build command
Allow to change build variables
(DIN_LOC_ROOT_CSMDATA, RUNDIR, DEBUG)
If you have modified source code, place code in the
BuildConf directory (before building)
Often: you don’t need to modify the build options

30. Running options (step 4)
Case directory
myFirstCase
Configure
env_run.xml
SourceMods
Tools
BuildConf
Run options are set in: env_run.xml
before running the model
Mostly likely: you will modify the run options
Allow to change run variables (CONTINUE_RUN, RESUBMIT, STOP_N, STOP_OPTION)

31. Outline Overview of model capabilities The 4 steps to run CESM
Options at each step
Post-processing tools
CESM webpages

32. Post-processing the output
CESM produces a large number of files with many variables
Post processing => can be challenging
Each component maintains its own post-processing tool
- can be accessed from the release code repository.
- currently provided only as a service to the community.
As an example: the atmosphere post-processing tool:
The atmospheric diagnostics package

33. The atmospheric diagnostics package
Post-processing tool to plot diagnostics for the atmosphere
The atmospheric diagnostics package produces over 600 plots and tables from the default CESM monthly means and displays the plots/tables on a webpage.
The atmospheric diagnostics package can be used:
to compare two model simulations
for comparing a model simulation to observations and reanalysis

34. The atmospheric diagnostics package

35. Zonal means Temperature versus ERA40
Shortwave cloud forcing versus CERES

36. Lat/Lon plots
Sea Surface Temperatures
compared to observations

37. Outline Overview of model capabilities The 4 steps to run CESM
Options at each step
Post-processing tools
CESM webpages

38. Data, Diagnostics, and Post- Processing Tools Component Model
CESM1 Release Web Page
Data, Diagnostics,
and Post-
Processing Tools
Component Model
Documentation
Input Data
How to Acquire
the Code
Known Problems
and Reporting
Problems
Background
and Sponsors
Notable
Improvements
User’ s Guide
External Libraries
Timing Table
Copyright and
Terms of Use
Version
Summaries
100608

39. Where to find help ? Documentation:
CESM bulletin board:

40. Info about diagnostics package

41. Summary CESM should be downloaded into 2 directories
Very easy to use: can be run with 4 commands !!!!
Step 1: create a new case
Step 2: configure
Step 3: build the executable
Step 4: run CESM
Multiple options at each step to customize your experiment
Post-processing tools are available for each component
A wealth of information is available on the CESM webpages
the CESM code
the CESM data