The Community Earth System Model

Composed of separate models simultaneously simulating the Earth's atmosphere, ocean, land, river run-off, land-ice, and sea-ice, plus one central coupler/moderator component, it allows researchers to conduct fundamental research into the Earth's past, present, and future climate states.
https://github.com/escomp/cesm

climate climate-model ncar

Last synced: about 12 hours ago
JSON representation

Repository metadata

The Community Earth System Model

• Host: GitHub
• URL: https://github.com/escomp/cesm
• Owner: ESCOMP
• License: other
• Created: 2017-11-15T18:10:55.000Z (over 6 years ago)
• Default Branch: master
• Last Pushed: 2024-05-06T18:56:02.000Z (5 days ago)
• Last Synced: 2024-05-07T06:06:27.947Z (5 days ago)
• Topics: climate, climate-model, ncar
• Language: Python
• Homepage: http://www.cesm.ucar.edu/
• Size: 12.1 MB
• Stars: 313
• Watchers: 36
• Forks: 178
• Open Issues: 29
• Metadata Files:
  • Readme: README.rst
  • Changelog: ChangeLog
  • License: LICENSE.txt
  • Code of conduct: CODE_OF_CONDUCT.md

README

        
==================================

 The Community Earth System Model

==================================

See the CESM web site for documentation and information:

http://www.cesm.ucar.edu

The CESM Quickstart Guide is available at:

http://escomp.github.io/cesm

This repository provides tools for managing the external components that

make up a CESM tag - alpha, beta and release. CESM tag creation should

be coordinated through CSEG at NCAR.

This repository is also connected to slack at http://cesm2.slack.com

.. sectnum::

.. contents::

Software requirements

=====================

Software requirements for installing, building and running CESM

---------------------------------------------------------------

Installing, building and running CESM requires:

* a Unix-like operating system (Linux, AIX, OS X, etc.)

* git client version 1.8 or newer

* subversion client (we have tested with versions 1.6.11 and newer)

* python3 version 3.6 or newer

* perl version 5

* build tools gmake and cmake

* Fortran and C compilers

  * See `Details on Fortran compiler versions`_ below for more information

* LAPACK and BLAS libraries

* a NetCDF library version 4.3 or newer built with the same compiler you

  will use for CESM

  * a PnetCDF library is optional

* a functioning MPI environment (unless you plan to run on a single core

  with the CIME mpi-serial library)

Details on Fortran compiler versions

------------------------------------

The Fortran compiler must support Fortran 2003 features. However, even

among mainstream Fortran compilers that claim to support Fortran 2003,

we have found numerous bugs. Thus, many compiler versions do *not* build

or run CESM properly (see

https://wiki.ucar.edu/display/ccsm/Fortran+Compiler+Bug+List for more

details on older Fortran compiler versions).

CESM2 is tested on several different systems with newer Fortran compilers:

Please see `CESM Compiler/Machine Tests `_

for a spreadsheet of the current results.

More details on porting CESM

----------------------------

For more details on porting CESM to a new machine, see

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

Obtaining the full model code and associated scripting infrastructure

=====================================================================

CESM is now released via github. You will need some familiarity with git in order

to modify the code and commit these changes. However, to simply checkout and run the

code, no git knowledge is required other than what is documented in the following steps.

To obtain the CESM code you need to do the following:

#. Clone the repository. ::

      git clone https://github.com/escomp/cesm.git my_cesm_sandbox

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

#. Go into the newly created CESM repository and determine what version of CESM you want.

   To see what cesm tags are available, simply issue the **git tag** command. ::

      cd my_cesm_sandbox

      git tag

#. Do a git checkout of the tag you want. If you want to checkout release-cesm2.1.2, you would issue the following. ::

      git checkout release-cesm2.1.2

   (It is normal and expected to get a message about being in 'detached

   HEAD' state. For now you can ignore this, but it becomes important if

   you want to make changes to your Externals.cfg file and commit those

   changes to a branch.)

#. Run the script **manage_externals/checkout_externals**. ::

      ./manage_externals/checkout_externals

   The **checkout_externals** script is a package manager that will

   populate the cesm directory with the relevant versions of each of the

   components along with the CIME infrastructure code.

At this point you have a working version of CESM.

To see full details of how to set up a case, compile and run, see the CIME documentation at http://esmci.github.io/cime/ .

More details on checkout_externals

----------------------------------

The file **Externals.cfg** in your top-level CESM directory tells

**checkout_externals** which tag/branch of each component should be

brought in to generate your sandbox. (This file serves the same purpose

as SVN_EXTERNAL_DIRECTORIES when CESM was in a subversion repository.)

NOTE: Just like svn externals, checkout_externals will always attempt

to make the working copy exactly match the externals description. For

example, if you manually modify an external without updating Externals.cfg,

(e.g. switch to a different tag), then rerunning checkout_externals

will automatically restore the externals described in Externals.cfg. See

below documentation `Customizing your CESM sandbox`_ for more details.

**You need to rerun checkout_externals whenever Externals.cfg has

changed** (unless you have already manually updated the relevant

external(s) to have the correct branch/tag checked out). Common times

when this is needed are:

* After checking out a new CESM branch/tag

* After merging some other CESM branch/tag into your currently

  checked-out branch

**checkout_externals** must be run from the root of the source

tree. For example, if you cloned CESM with::

  git clone https://github.com/escomp/cesm.git my_cesm_sandbox

then you must run **checkout_externals** from

``/path/to/my_cesm_sandbox``.

To see more details of **checkout_externals**, issue ::

  ./manage_externals/checkout_externals --help

Customizing your CESM sandbox

=============================

There are several use cases to consider when you want to customize or modify your CESM sandbox.

Switching to a different CESM tag

---------------------------------

If you have already checked out a tag and **HAVE NOT MADE ANY

MODIFICATIONS** it is simple to change your sandbox. Say that you

checked out release-cesm2.1.2 but really wanted to have release-cesm2.1.3;

you would simply do the following::

  git checkout release-cesm2.1.3

  ./manage_externals/checkout_externals

You should **not** use this method if you have made any source code

changes, or if you have any ongoing CESM cases that were created from

this sandbox. In these cases, it is often easiest to do a second **git

clone**.

Pointing to a different version of a component

----------------------------------------------

Each entry in **Externals.cfg** has the following form (we use CAM as an

example below)::

  [cam]

  tag = trunk_tags/cam5_4_143/components/cam

  protocol = svn

  repo_url = https://svn-ccsm-models.cgd.ucar.edu/cam1

  local_path = components/cam

  required = True

Each entry specifies either a tag or a branch. To point to a new tag:

#. Modify the relevant entry/entries in **Externals.cfg** (e.g., changing

   ``cam5_4_143`` to ``cam5_4_144`` above)

#. Checkout the new component(s)::

     ./manage_externals/checkout_externals

Keep in mind that changing individual components from a tag may result

in an invalid model (won't compile, won't run, not scientifically

meaningful) and is unsupported.

Committing your change to Externals.cfg

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

After making this change, it's a good idea to commit the change in your

local CESM git repository. First create a CESM branch in your local

repository, then commit it. (Unlike with subversion, branches are stored

locally unless you explicitly push them up to github. Feel free to

create whatever local branches you'd like.) For example::

  git checkout -b my_cesm_branch

  git add Externals.cfg

  git commit -m "Update CAM to cam5_4_144"

Modifying a component

---------------------

If you'd like to modify a component via a branch and point to that

branch in your CESM sandbox, use the following procedure (again, using

CAM as an example):

#. Create a CAM branch. Since CAM originates from a subversion

   repository, you will first need to create a branch in that

   repository. Let's assume you have created this branch and called it

   **my_branch**.

#. Update **Externals.cfg** to point to your branch. You can replace the

   **tag** entry with a **branch** entry, as follows::

     [cam]

     branch = branches/my_branch/components/cam

     protocol = svn

     repo_url = https://svn-ccsm-models.cgd.ucar.edu/cam1

     local_path = components/cam

     required = True

#. Checkout your branch::

     ./manage_externals/checkout_externals

It's a good idea to commit your **Externals.cfg** file changes. See the above

documentation, `Committing your change to Externals.cfg`_.

Developer setup

===============

Developers who have not already done so should follow the recommended

`one-time `_

setup directions for git. Developers may also want to set up

`ssh `_

keys and switch to using the ``[email protected]:ESCOMP/cesm.git`` form of the github URLs.

      

---

Owner metadata

• Name: Earth System Community Modeling Portal
• Login: ESCOMP
• Email:
• Kind: organization
• Description:
• Website: https://escomp.github.io/
• Location:
• Twitter:
• Company:
• Icon url: https://avatars.githubusercontent.com/u/33552285?v=4
• Repositories: 45
• Last ynced at: 2023-02-28T06:55:14.867Z
• Profile URL: https://github.com/ESCOMP

---

GitHub Events

Total

• Fork event: 129
• Create event: 185
• Release event: 3
• Issues event: 78
• Watch event: 233
• Delete event: 48
• Member event: 3
• Issue comment event: 199
• Push event: 536
• Gollum event: 23
• Pull request review comment event: 42
• Pull request event: 138
• Pull request review event: 67

Last Year

• Create event: 40
• Delete event: 6
• Fork event: 29
• Issue comment event: 30
• Issues event: 22
• Member event: 1
• Pull request event: 22
• Pull request review comment event: 7
• Pull request review event: 21
• Push event: 96
• Watch event: 53

---

Committers metadata

Last synced: 2 days ago

Name	Email	Commits
Chris Fischer	f****r@u****u	365
Bill Sacks	s****s@u****u	116
Ben Andre	b****e@g****m	95
Ben Andre	a****e@u****u	57
Jim Edwards	j****s@u****u	54
Alice Bertini	a****b@u****u	19
Steve Goldhaber	g****y@u****u	12
mvertens	m****s@u****u	8
Erik Kluzek	e****k@u****u	7
Francis Vitt	f****t@u****u	6
Chris A. Fischer	f****r@i****u	5
alperaltuntas	a****s@g****m	5
Katetc	k****c@u****u	3
allibco	a****r@u****u	3
Michael Levy	m****k@g****m	2
Chris A. Fischer	f****r@h****u	2
Chris A. Fischer	f****r@i****u	2
Alper Altuntas	a****s@c****u	1
Chris Fischer	c****r@e****v	1
Jian Sun	s****n@u****u	1

Committer domains:

• ucar.edu: 12
• edison10.nersc.gov: 1
• cheyenne5.ib0.cheyenne.ucar.edu: 1
• izumi.cgd.ucar.edu: 1
• hobart.cgd.ucar.edu: 1
• izumi.unified.ucar.edu: 1

---

Issue and Pull Request metadata

Last synced: 1 day ago

More stats: https://issues.ecosyste.ms/repositories/lookup?url=https://github.com/escomp/cesm

---

---

---

Dependencies

Score: 8.830543010616596