The Build Environment

The build and configure environment has changed significantly from previous versions of CESM. The build namelist and configure utilities are based on the CAM scripts ().

The configure utility includes setting compile time parameters such as the horizontal grid, the sea ice mode (prognostic or prescribed), tracers, etc. Additional options can be set using the configure utility such as the decomposition, and the number of tasks, but these are typically set via CESM enviroment variables. However, the CAM scripts set some of these explicitly through the configure command line. For example one such configure line in the CESM scripts is:

#--------------------------------------------------------------------
# Invoke cice configure
#--------------------------------------------------------------------


set hgrid = "-hgrid $ICE_GRID"
if ($ICE_GRID =~ *T*) set hgrid = "-hgrid ${ICE_NX}x${ICE_NY}"

set mode = "-cice_mode $CICE_MODE"

cd $CASEBUILD/ciceconf || exit -1
$CODEROOT/ice/cice/bld/configure $hgrid $mode -nodecomp $CICE_CONFIG_OPTS || exit -1

This example sets the horizontal grid and the mode (prognostic or prescribed). The build namelist utility sets up the namelist which controls the run time options for the CICE model. This utility sets namelist flags based on compile time settings from configure and some standard defaults based on horizontal grids and other options. The typical execution during the CESM configure is:

  $CODEROOT/ice/cice/bld/build-namelist -config config_cache.xml \
         -csmdata \$DIN_LOC_ROOT -infile ccsm_namelist \
         -inputdata $CASEBUILD/cice.input_data_list \
         -namelist "&cice $CICE_NAMELIST_OPTS /" || exit -1

Again, the typical usage of the build namelist tool is through the CESM scripts, but can be called via the command line interface.