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Setting up an AMIP Experiment

Matt Thompson edited this page Jul 18, 2024 · 6 revisions

Once the model has built successfully, you will have an install/ directory in your source code main directory. We recommend that you always execute the "setup" script that has a suite of default configurations and is meant to create an experiment directory. Go to the install/bin/ directory and run the gcm_setup script:

./gcm_setup

You will answer a series of questions to determine the model configuration (horizontal resolution, vertical resolution, Aerosols type, etc.) you are interested in. In all the following steps, gcm_setup will often display a "default". If so, you can press Enter to accept the default.

1 Experiment Information

The gcm_setup script asks you to provide an experiment name. Your experiment name (later called EXPID) should be one word with no spaces, not starting with a numeral.

Enter the Experiment ID:
test-c48

Then the script will ask for a description:

Enter a 1-line Experiment Description:
test-c48

Spaces are ok here.

2 Using Settings from a Previous Experiment

Next it will ask if you wish to CLONE (use settings from a previous experiment) an experiment. If yes, you can point this to an existing experiment directory and the setup script will try and duplicate all the RC files, initial data files, etc..

Do you wish to CLONE an old experiment? (Default: NO or FALSE)

For now, though, choose NO to create a new experiment.

3 Atmospheric Model Resolution

You will now be asked to provide the atmospheric model resolution, expecting the code for one of the displayed resolutions.

Enter the Atmospheric Horizontal Resolution code:
--------------------------------------
            Cubed-Sphere
--------------------------------------
   c12  -- 8    deg (750.0    km)
   c24  -- 4    deg (375.0    km)
   c48  -- 2    deg (187.5    km)
   c90  -- 1    deg (100.0    km)
   c180 -- 1/2  deg ( 50.0    km)
   c360 -- 1/4  deg ( 25.0    km)
   c720 -- 1/8  deg ( 12.5    km)
   c1440 - 1/16 deg (  6.25   km)
   c2880 - 1/32 deg (  3.125  km)
   c5760 - 1/64 deg (  1.5625 km)
            CONUS Stretched Grids
   c270 --  16.0 -100 km)
   c540 --   8.0 - 50 km)
   c1080 -   4.0 - 25 km)
   c1536 -   2.0 - 20 km)
   c2160 -   2.0 - 12 km)

If you are attempting to run the code for the first time, we recommend that you enter c48.

Next it will ask you about the vertical resolution:

Enter the Atmospheric Model Vertical Resolution: LM (Default: 72)

As you can see, this question has a default of 72, which is the vertical resolution GEOS is normally run at, though support exists for 91, 137, and 181 levels. It is important to note that emissions or other boundary conditions might need to be made to fully support other vertical resolutions.

Here, choose the default of 72.

4 Moist Microphysics

Provide the moist microphysics you wish to run:

Enter Choice for Atmospheric Model Microphysics: (Default: BACM_1M)
   BACM_1M  --  3-phase 1-moment Bacmeister et al
   GFDL_1M  --  6-phase 1-moment Geophysical Fluid Dynamics Laboratory
   MGB2_2M  --  5 or 6-phase 2-moment Morrison & Gettleman

Again, choose the default of BACM_1M.

5 Hydrostatic Atmospheric Dynamics

Next, it will ask if you want to use hydrostatic atmospheric dynamics:

Use Hydrostatic Atmosphere? (Default: TRUE)

Unlike many questions, the default for this might change depending on how GEOS was built. Unless you know what you are doing, accepting the default here is advised.

6 Use IOserver and Type of Processor

The next question will involve the IOserver. This is a capability of GEOS (specifically pFIO in MAPL) to handle (some) input/output (I/O) on nodes external to the model. This way the model can run and asynchronously output without stopping the model. The default answer to this question is resolution-dependent. At lower resolutions (c12, c24, c48), this is defaulted to NO as it is often unnecessary. But at higher-resolutions, it defaults to YES. NOTE: That if you enable the IOserver, it increases the number of nodes you need, though usually only by a few even at the highest resolutions (see here for more info).

Do you wish to IOSERVER? (Default: NO or FALSE)

As usual, accept the default.

Next we will ask which processor type you wish to run on. This question is only valid at NCCS and NAS where we know the processors of the cluster, and the accepted answers will change depending on the center. If you plan to use a NCCS platform you will see the options:

Enter the Processor Type you wish to run on:
   mil (Milan) (default)

Note: Above is what will be seen if built on SLES15 at NCCS.

7 Selection of the Coupled Ocean Model

Next it will ask if you want to run the coupled ocean model. If you wish to, we refer you to other documentation for the setting up coupled model.

Do you wish to run the COUPLED Ocean/Sea-Ice Model? (Default: NO or FALSE)
NO

For our case, reply NO. When you answer NO, it will then ask which ocean to run. The default is Reynolds (o1) for all resolutions, though at C90 and above, we recommend the Ostia (o3) or cubed-sphere (CS) oceans.

Enter the Data_Ocean Horizontal Resolution code: o1 (1  -deg,  360x180  Reynolds) Default
                                                 o2 (1/4-deg, 1440x720  MERRA-2)
                                                 o3 (1/8-deg, 2880x1440 OSTIA)
                                                 CS (Cubed-Sphere OSTIA)

For c48, choose the default of o1.

8 Selection of the Surface Models

The next two questions involve the surface models being used. For most users, the defaults of Icarus-NLv3 and Catchment are appropriate:

Enter the choice of  Land Surface Boundary Conditions using: 1 (Icarus), 2 (Default: Icarus-NLv3)
2

Enter the choice of  Land Surface Model using: 1 (Default: Catchment), 2 (CatchmentCN-CLM4.0 (CN_CLM40)), 3 (CatchmentCN-CLM4.5 (CN_CLM45))
1

9 Selection of the Aerosols

The next questions will ask about the Aerosols used with GOCART. Here we'll select Actual aerosols and the AMIP set of files:

Do you wish to run GOCART with Actual or Climatological Aerosols? (Enter: A (Default) or C)
A

Enter the GOCART Emission Files to use: AMIP (Default) or OPS:
AMIP

AMIP Caveat

Due to a lack of some data after Jun 2017, if you wish to run an experiment after that date, you should choose OPS above instead of AMIP. If you are using the sample restarts mentioned in Running an AMIP Experiment, those are for the year 2000 and so AMIP will work.

10 Heartbeat

The next question asks about the model heartbeat to use:

Enter HEARTBEAT_DT to use
   1. Hit ENTER to use the recommended default of 450
   2. Type an integer (in seconds) to overide the default value

For now, just hit ENTER to select the default.

11 Other Model Setups

After this are some questions about various setups in the model. The default is often your best bet if you are not sure. First a question about the history template to use:

Enter the filename of the HISTORY template to use
-----------------------------------------------------------
As Data Ocean (o1) was chosen, the default HISTORY Template is HISTORY.AGCM.rc.tmpl
  1. Hit ENTER to use the default HISTORY template (HISTORY.AGCM.rc.tmpl) or
  2. Type the full path of the HISTORY template to use

Then questions about where to put the model. NOTE: Some/Many things are easier if your HOME and EXPERIMENT directories are the same. For the next two, look carefully at the default and make sure they are both pointing to the same nobackup location.

Enter Desired Location for the HOME Directory (to contain scripts and RC files)
Hit ENTER to use Default Location:
----------------------------------
Default:  /discover/nobackup/mathomp4/Experiments/test-c48


Enter Desired Location for the EXPERIMENT Directory (to contain model output and restart files)
Hit ENTER to use Default Location:
----------------------------------
Default:  /discover/nobackup/mathomp4/Experiments/test-c48

After these it will ask you for a group ID -- the default here is g0620, but it might be different for you. Enter whatever is appropriate for your work:


Current GROUPS: g0620 s1872 s1873 s2826 k3002 nvhpc-beta g5extdata gmaoint gmaosi advda m2val
Enter your GROUP ID for Current EXP: (Default: g0620)
-----------------------------------

The script will produce some messages and create an experiment directory (EXPDIR) in your space as a la /discover/nobackup/USERID/EXPID, which contains the files and sub-directories:

Creating gcm_run.j for Experiment: test-c48
Creating gcm_post.j for Experiment: test-c48
Creating gcm_archive.j for Experiment: test-c48
Creating gcm_regress.j for Experiment: test-c48
Creating gcm_convert.j for Experiment: test-c48
Creating gcm_plot.tmpl for Experiment: test-c48
Creating gcm_quickplot.csh for Experiment: test-c48
Creating gcm_moveplot.j for Experiment: test-c48
Creating gcm_forecast.tmpl for Experiment: test-c48
Creating gcm_forecast.setup for Experiment: test-c48
Creating gcm_emip.setup for Experiment: test-c48
Creating CAP.rc.tmpl for Experiment: test-c48
Creating AGCM.rc.tmpl for Experiment: test-c48
Creating HISTORY.rc.tmpl for Experiment: test-c48
Creating logging.yaml for Experiment: test-c48
Creating fvcore_layout.rc for Experiment: test-c48

Done!
-----

Build Directory: /gpfsm/dnb44/mathomp4/SystemTests/builds/AGCM/CURRENT/GEOSgcm/install-Release
----------------


The following executable has been copied to your Experiment Directory:
----------------------------------------------------------------------
/gpfsm/dnb44/mathomp4/SystemTests/builds/AGCM/CURRENT/GEOSgcm/install-Release/bin/GEOSgcm.x


You must now copy your Initial Conditions into:
-----------------------------------------------
/discover/nobackup/mathomp4/Experiments/test-c48

You can now proceed to running an experiment

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