CUG_Introduction

Introduction to CIME

CIME contains the support scripts, data models, essential utility libraries, a “main” and other tools that are needed to build a single-executable coupled Earth System Model.

CIME is comprised of:

1. A default coupled model architecture:

   1. A programmer interface and libraries (including MCT) to implement a hub-and-spoke inter-component coupling architecture.
   2. An implementation of a “hub” that needs 7 components (atm, ocn, lnd, sea-ice, land-ice, river, wave). a.k.a. “the driver”.
   3. The ability to allow prognostic and data components to be mixed in any combination as long as each component implements the coupling programmer interface.

2. Non-prognostic Data and Stub components

   1. “Data-only” versions of 6 of the 7 components that can replace prognostic components at build-time.
   2. “Stub” versions of all 7 components for building a complete system.

3. A system of scripts (perl, csh and python) to support case configuration, executable compilation, workflow, system testing and unit testing infrastructure:

   1. Scripts to enable simple generation of model executables and associated input files for different scientific cases, component resolutions and combinations of full, data and stub components with a handful of commands.
   2. Testing utilities to run defined system tests and report results for different configurations of the coupled system.

4. Additional stand-alone utilities and libraries useful in scientific applications in general and climate models in particular.

   1. Parallel I/O library
   2. Timing library

   3. Stand-alone programs

      1. Parallel regridding weight generation program
      2. Scripts to automate off-line load-balancing.
      3. Scripts to conduct ensemble-based statistical consistency tests.
      4. Netcdf file comparison program (for bit-for-bit).

CIME is available in a stand-alone package that can be compiled and tested without full prognostic components (by using the included data models)

CIME does not contain any prognostic components. In addition, CIME does not contain any intra-component coupling capability (such as CAM physics-dynamics coupling)