A. P. Craig, M. Vertenstein, and R. Jacob, "A New Flexible Coupler for Earth System Modeling Developed for CCSM4 and CESM1," International Journal of High Performance Computing Applications, vol. 25, no. 4, 2011, . Also Preprint ANL/MCS-P1838-0111, January 2011. [pdf]
The Community Climate System Model (CCSM) has been developed over the last decade, and it is used to understand past, present, and future climates. The latest versions of the model, CCSM4 and CESM1, contain totally new coupling capabilities in the CPL7 coupler that permit additional flexibility and extensibility to address the challenges involved in earth system modeling. An integral part of CPL7 is the implementation of a coupling architecture that takes a completely new approach with respect to the high-level design of the system. CCSM4 now contains a top-level driver that calls model component init, run, and finalize methods through specified interfaces. The top-level driver allows the model components to be placed on relatively arbitrary hardware processor layouts and run sequentially, concurrently, or mixed. The new coupling architecture continues to provide "plug and play" capability of data and active components, but improvements have been made to the memory and performance scaling of the coupler that support much higher resolution configurations. CCSM4 now scales better to higher processor counts, and the ability to handle global resolutions up to one-tenth degree is demonstrated.