CESM

Model description

'*** IMPORTANTE: PAGINA EN CONSTRUCCION***

The Community Earth System Model (CESM) is a fully-coupled, community, global climate model that provides state-of-the-art computer simulations of the Earth's past, present, and future climate states. The CESM project is supported primarily by the National Science Foundation (NSF). Administration of the CESM is maintained by the Climate and Global Dynamics Laboratory (CGD) at the National Center for Atmospheric Research (NCAR).

For the latest CESM release and CESM2 components see CESM2 documentation.

Downloading CESM2

Following CESM2 Quick Start Guide and CESM2 github instructions.

Clone the repository

git clone -b release-cesm2.2.2 git@github.com:ESCOMP/CESM.git my_cesm_sandbox

This will create a directory my_cesm_sandbox/ in your current working directory.

We got the following

$ cd my_cesm_sandbox/
$ ls
ChangeLog           CODE_OF_CONDUCT.md  Externals.cfg       manage_externals
ChangeLog_template  describe_version    Externals_cime.cfg  README.rst
cime_config         doc                 LICENSE.txt

Verifying that installation was fine:

$ ./manage_externals/checkout_externals
$ ls 
ChangeLog           CODE_OF_CONDUCT.md  Externals.cfg       README.rst
ChangeLog_template  components          Externals_cime.cfg
cime                describe_version    LICENSE.txt
cime_config         doc                 manage_externals

Defining the compilation / installation

Machine

We need to create the configuration for hydra. For that purpose we are going to use the exampled configuration for "centos7-linux" from file

cime/config/cesm/machines/config_machines.xml

. This is its content_

  <machine MACH="centos7-linux">
    <DESC>
      Example port to centos7 linux system with gcc, netcdf, pnetcdf and mpich
      using modules from http://www.admin-magazine.com/HPC/Articles/Environment-Modules
    </DESC>
    <NODENAME_REGEX>regex.expression.matching.your.machine</NODENAME_REGEX>
    <OS>LINUX</OS>
    <PROXY> https://howto.get.out </PROXY>
    <COMPILERS>gnu</COMPILERS>
    <MPILIBS>mpich</MPILIBS>
    <PROJECT>none</PROJECT>
    <SAVE_TIMING_DIR> </SAVE_TIMING_DIR>
    <CIME_OUTPUT_ROOT>$ENV{HOME}/cesm/scratch</CIME_OUTPUT_ROOT>
    <DIN_LOC_ROOT>$ENV{HOME}/cesm/inputdata</DIN_LOC_ROOT>
    <DIN_LOC_ROOT_CLMFORC>$ENV{HOME}/cesm/inputdata/lmwg</DIN_LOC_ROOT_CLMFORC>
    <DOUT_S_ROOT>$ENV{HOME}/cesm/archive/$CASE</DOUT_S_ROOT>
    <BASELINE_ROOT>$ENV{HOME}/cesm/cesm_baselines</BASELINE_ROOT>
    <CCSM_CPRNC>$ENV{HOME}/cesm/tools/cime/tools/cprnc/cprnc</CCSM_CPRNC>
    <GMAKE>make</GMAKE>
    <GMAKE_J>8</GMAKE_J>
    <BATCH_SYSTEM>none</BATCH_SYSTEM>
    <SUPPORTED_BY>me@my.address</SUPPORTED_BY>
    <MAX_TASKS_PER_NODE>8</MAX_TASKS_PER_NODE>
    <MAX_MPITASKS_PER_NODE>8</MAX_MPITASKS_PER_NODE>
    <PROJECT_REQUIRED>FALSE</PROJECT_REQUIRED>
    <mpirun mpilib="default">
      <executable>mpiexec</executable>
      <arguments>
        <arg name="ntasks"> -np {{ total_tasks }} </arg>
      </arguments>
    </mpirun>
    <module_system type="module" allow_error="true">
      <init_path lang="perl">/usr/share/Modules/init/perl.pm</init_path>
      <init_path lang="python">/usr/share/Modules/init/python.py</init_path>
      <init_path lang="csh">/usr/share/Modules/init/csh</init_path>
      <init_path lang="sh">/usr/share/Modules/init/sh</init_path>
      <cmd_path lang="perl">/usr/bin/modulecmd perl</cmd_path>
      <cmd_path lang="python">/usr/bin/modulecmd python</cmd_path>
      <cmd_path lang="sh">module</cmd_path>
      <cmd_path lang="csh">module</cmd_path>
      <modules>
        <command name="purge"/>
      </modules>
      <modules compiler="gnu">
        <command name="load">compiler/gnu/8.2.0</command>
        <command name="load">mpi/3.3/gcc-8.2.0</command>
        <command name="load">tool/netcdf/4.6.1/gcc-8.1.0</command>
        <command name="load">tool/parallel-netcdf/1.12.1/mpich</command>
      </modules>
    </module_system>
    <environment_variables>
      <env name="OMP_STACKSIZE">256M</env>
    </environment_variables>
    <resource_limits>
      <resource name="RLIMIT_STACK">-1</resource>
    </resource_limits>
  </machine>

Work-flow

configuration of the work-flow is done via the file

config_batch.xml

http://esmci.github.io/cime/versions/master/html/users_guide/machine.html

Porting and validating CIME on a new platform

http://esmci.github.io/cime/versions/master/html/users_guide/porting-cime.html

Downloading the Input data

Input datasets are needed to run the model. CESM input data are available through a separate Subversion input data repository.

• Change check_input_data header so it runs with Python 2.7.x version:

sed -i -e 's!/usr/bin/env python!/share/anaconda2/bin/python!' ./cime/scripts/Tools/check_input_data