This document provides a brief synopsis of the download, compilation
and execution procedure for the the Earth System Modeling
Framework (http://www.esmf.ucar.edu) JMC code L First Improvment.
The code and its time to solution measurements
are part of ESMF joint milestone F.
Code L is a coupled 
ocean atmosphere configuration
of the MIT General Circulaiton Model (MITgcm). This configuration
is actively in use for research into
air-sea dynamical and biogeochemical couplings, especially on interannual, decadal, centennial
and greater timescales.
Details of the code configuration can be found under the
Applications link at http://www.esmf.ucar.edu.
Reference material for the MITgcm code can be found
at http://mitgcm.org
and
specific information on the current JMC code L setup
and its future evolution over the ESMF project
can be found
at http://mitgcm.org/projects/ESMF/JMClimprov1.
The milestone F configuration provides an ESMF development cycle reference point for a time to solution metric evaluating ESMF framework overheads. In this test code L has evolved internally and the framework can now replace many parts of the codes' native infrastructure and superstructure. Two forms of code L exist, one outside the framework and one that makes use of the framework. These two forms are used to establish the time to solution, for an identical problem.
The problem used to measure time to solution is a ten-day coupled simulation starting from the saved state of a 50 year coupled spin-up. This milestone will gives the time to solution for both framework and non-framework code. At this stage, part way through framework development, the time to solution is calculated and found to be significantly increased when using the framework. Section 2 describes how to download the code for L first improvement. Sections 4 and 5 describe the steps for compilation, execution and validation of the results on the MITgcm cluster. The exact procedures and pathnames described are tailored to the configuration of the MITgcm cluste system cg01.lcs.mit.edu. However, the MITgcm code and the ESMF code can both execute on many other platforms and many of the steps are the same for other platforms and systems.