User's Guide

This guide provides instructions for obtaining, compiling and running a simple case for the GMTB single column model (SCM). The SCM code calls CCPP-compliant physics schemes through the CCPP infrastructure code. As such, it requires the CCPP infrastructure code and physics code, both of which are included as git submodules within the SCM code. This package can be considered a simple example for an atmospheric model to interact with physics through the CCPP.

Obtaining Code

1. Download a compressed file or clone the source using

• git clone https://[username]@github.com/NCAR/gmtb-scm.git and enter your github password when prompted.

2. Change directory into the project.

• cd gmtb-scm

3. Initialize the CCPP infrastructure and physics submodules.

• git submodule init

4. Update (download) the submodules.

• git submodule update and, if asked, enter your github credentials again. If the machine is running an older version of git and you are denied access, you may need to configure the submodule URLs before repeating step 4 by executing this command:
  • git config submodule.ccpp-framework.url https://[username]@github.com/NCAR/ccpp-framework.git
  • git config submodule.ccpp-physics.url https://[username]@github.com/NCAR/ccpp-physics.git

Building and Compiling the SCM with CCPP

1. Run the CCPP prebuild script to match required physics variables with those available from the dycore (SCM) and to generate physics caps and makefile segments.

• ./ccpp-framework/scripts/ccpp_prebuild.py --model=SCM Note: add --debug to see the full output of the script.

2. Change directory to the top-level SCM directory.

• cd scm

3. [Optional] Run the machine setup script if necessary. This script loads compiler modules (Fortran 2003-compliant), netCDF module, etc. and sets compiler environment variables.

• source etc/Theia_setup_intel.csh (for csh) or . etc/Theia_setup_intel.sh (for bash)
• source etc/Theia_setup_pgi.csh (for csh) or . etc/Theia_setup_pgi.sh (for bash)
• source etc/Cheyenne_setup_intel.csh (for csh) or . etc/Cheyenne_setup_intel.sh (for bash)
• source etc/Cheyenne_setup_pgi.csh (for csh) or . etc/Cheyenne_setup_pgi.sh (for bash)
• source etc/UBUNTU_setup.csh (for csh) or . etc/UBUNTU_setup.sh (for bash) if following the instructions in doc/README_UBUNTU.txt
• source etc/CENTOS_setup.csh (for csh) or . etc/CENTOS_setup.sh (for bash) if following the instructions in doc/README_CENTOS.txt
• source etc/MACOSX_setup.csh (for csh) or . etc/MACOSX_setup.sh (for bash) if following the instructions in doc/README_MACOSX.txt

4. Make a build directory and change into it.

• mkdir bin && cd bin

5. Invoke cmake on the source code to build.

• cmake ../src (without threading/OpenMP)
• cmake -DOPENMP=1 ../src (with threading/OpenMP)

For extensive debugging output, add -DCMAKE_BUILD_TYPE=Debug to the cmake command. 6. Compile. Add VERBOSE=1 to obtain more information on the build process.

• make

Running the SCM with CCPP

1. Run the SCM with the supplied case (twpice). The SCM will go through the time steps, applying forcing and calling the physics defined in the suite definition file.

• ./gmtb_scm twpice

2. A netcdf output file is generated in the location specified in the case configuration file. For the twpice case, it is located in ./output_twpice/output.nc