Climate through a Prism
Despite recent developments in Earth system models (ESMs), the software environment of climate modelling has become exceedingly intricate, mainly due to the lack of standardisation in the computational platforms used. The need for a common software infrastructure with standard data formats, which facilitate broader exchange and analysis of model results, was addressed by the PRISM project. PRISM (Programme for integrated earth system modelling), provides an advanced software and hardware environment under which Earth System Models developed in the different climate research centres can be developed, improved, and integrated. The requirements of portability, flexibility and extendibility at low maintenance costs, have led to highly modularised software. The PRISM models have to meet minimum standards in order to allow the use of the PRISM tools for model development and automatic processing. In this direction, the Standard Compile Environment (SCE), a central aspect of the PRISM infrastructure, provides a common and user-friendly frame for source code management and model compilation. The SCE is designed in an open and flexible way and defines standards for many aspects of Earth System modelling experiments. For example the simple structure used for the standard directory for the storage of model and library source codes allows model compilation with a portable toolbox. The SCE does not comprise ready-to-use scripts, but provides a comprehensive set of utilities to generate model and platform specific compile scripts. The scripts are assembled from a base of fragments of script code. These fragments are specific for a model or a platform or both, or they can be used for all models on all platforms. In this way, the identification of the necessary fragments for newly coupled models or new platforms is made easy. In addition, redundant code is avoided, minimising the maintenance costs of the system. The development of the SCE is an ongoing process, since new model or platforms might have new demands on the system. However it is currently available both as part of the PRISM system and as a stand-alone tool to scientists or institutes which intend to exploit its potential for their activities.
