CESM 2.0 Users Guide

CESM2.0 User's Guide

Authors:	NCAR - CESM Software Engineering Group
Version:	0.1.0

Contents:

.. toctree::
   :maxdepth: 2

1. Introduction

• How To Use This Document
  • CESM Model Version Naming Conventions
• CESM Overview
  • CESM Software/Operating System Prerequisites
  • CESM Components
  • CESM Component Sets
  • CESM Grids
  • CESM Machines
  • CESM Validation
• Downloading CESM
  • Downloading the code and scripts - starting with CESM1.2.1
  • Obtaining new release versions of CESM - prior to CESM1.2.1
  • Downloading input data
• Quick Start (CESM Workflow)

2. Creating and Setting Up A Case

• How to create a new case
  • New Component Set Naming Convention
  • New Overall Model Grid Naming Convention
  • Using create_newcase
• How to set up a case and customize the PE layout
  • Calling cesm_setup
  • Changing the PE layout
• Multi-instance component functionality
• Modifying an xml file
• Cloning a case (Experts only)

3. Building CESM

• How do I build my model?
• Input data
  • User-created input data
  • Using the input data server
  • Rebuilding the model

4. Running CESM

• Customizing runtime settings - Controlling starting, stopping and restarting a run - Customizing component-specific namelist settings - Controlling output data
• Load balancing a case
  • Model timing data
  • Using model timing data
• How do I run a case?
  • Setting the time limits
  • Submitting the run
  • Restarting a run
  • Data flow during a model run
• Testing a case

5. Porting and Validating CESM on a new platform

• Porting Overview
• Step 1: Use create_newcase with a userdefined machine name
• Step 2: Enabling out-of-the box capability for your machine
• Step 3: Port Validation

6. Use Cases and FAQs

• BASICS: A basic example
• BASICS: How do I set up a branch or hybrid run?
• BASICS: What calendars are supported in CESM?
• BASICS: How do I change processor counts and component layouts on processors?
• BASICS: What are CESM xml variables and CESM environment variables?
• BASICS: How do I modify the value of CESM xml variables?
• BASICS: Why aren't my $CASEROOT xml variable changes working?
• BASICS: How do I run multiple cases all using a single executable?
• BASICS: How do I use the ESMF library and ESMF interfaces?
• BASICS: Why is there file locking and how does it work?
• BASICS: What are the directories and files in my case directory?
• IO: What is pio?
• IO: How do I use pnetcdf?
• CAM: How do I customize CAM output fields?
• CAM: How do I customize CAM forcings?
• CAM/CLM: How do I change history file output frequency and content for CAM and CLM during a run?
• CAM: How do I use B compset history output to create SST/ICE data files to drive an F compset?
• POP/CICE: How are CICE and POP decompositions set and how do I override them?
• POP: How do I initialize POP2 with a spun-up initial condition?
• DRIVER: Is there more information about the coupler/driver implementation?
• DRIVER: How do I pass in new fields between components?
• EXPERTS: How do I add a new user-defined component set?
• EXPERTS: How do I add a new user-defined grid?
• EXPERTS: How do I carry out data assimilation using CAM and DART?
• EXPERTS: How do I add a new CESM model component?

7. CESM Testing

• Testing overview
• Using create_production_test
• Using query_tests
• Using create_test
• Debugging Tests That Fail

8. Troubleshooting

• Troubleshooting create_newcase
• Troubleshooting job submission problems
• Troubleshooting runtime problems
• Additional Troubleshooting Information

Glossary

List of Tables

• 1-1. Recommmended Software Package Versions by Machine
• 2-1. Result of invoking create_newcase
• 2-2. Result of calling cesm_setup