View source for GEOS GCM Documentation and Access

This page describes the minimum steps required to checkout GEOS GCM. 

'''NOTE NOTE NOTE:''' This is only to get the '''code''' for the GEOS GCM. If you wish to use the production output from GEOS as run at the GMAO, please refer to the [https://gmao.gsfc.nasa.gov/GMAO_products/ GMAO page on GEOS products].

== Checking Out GEOS GCM using Git ==

The commands below assume that you have git 2.x installed on your machine. 

The GEOS GCM can be found here:

 https://github.com/GEOS-ESM/GEOSgcm

You can then clone with

 git clone https://github.com/GEOS-ESM/GEOSgcm

but note that GEOS GCM is what we call a "fixture" that is quite lightweight and you'll see the source tree is mainly empty. In order to get the rest of GEOS, you need to use a utility called [https://github.com/ESMCI/manage_externals checkout_externals]. Once you have that installed, you run:

 checkout_externals

inside the GEOSgcm directory. This then checks out all the sub-repositories needed for GEOS.

The code is publicly available, but in order to contribute to the GEOS GCM development, you will need to be added as a collaborator with the [https://github.com/GEOS-ESM GEOS-ESM] organization. Please send an email to [mailto:geos5-support@lists.nasa.gov GEOS Support] with your GitHub username. You can create tickets through the GitHub issue system and contribute to the code.

== Building GEOS ==

'''NOTE:''' GMAO does '''not''' generally support building or running GEOS on systems other than on NASA Supercomputers. 

GEOS GCM can be built, but you will need a variety of programs. An F90 compiler (Intel and GCC are supported and tested) and an MPI stack (Open MPI, Intel MPI, MVAPICH2, and SGI MPT have been tested). Beyond that, you'll also need the [https://github.com/GEOS-ESM/ESMA-Baselibs ESMA Baselibs], a collection of base libraries for GEOS which include HDF5, netCDF-C, netCDF-Fortran, ESMF, and more. Note that while these can be built individually, GEOS at present expects the libraries to be bundled in a specific way (directory-wise) to work.

== Boundary Conditions ==

[[Ganymed 4.1 Boundary Conditions|Boundary conditions]] are available at NCCS, NAS, and on GMAO Desktops (limited to ''very'' low-res).

A minimal, small set of boundary conditions of approximately 300 MB (4-degree resolution or coarser, probably could only run a few model days) have been made and could possibly be distributed if needed. Contact [mailto:matthew.thompson@nasa.gov Matthew Thompson] for further inquiries.