ing groups). In the process, much has been learned about how best to do this (see also Chapter 2), and it is now worth investing in the adoption of a common approach across all U.S. modeling centers over the next 5-10 years. The committee anticipates that the proposed annual Forum could play a key role as a venue for working strategic discussions on how to make this happen.
To make a common national software infrastructure a reality, there need to be compelling incentives and benefits for all modeling centers to adopt a common approach, beyond facilitation of collaboration and code exchange. As noted in Chapter 10, the committee believes that cross-laboratory intercomparison experiments are a crucial part of the path forward to advancing U.S. climate models and a common national software infrastructure has the potential to facilitate in-depth comparison between models, including interchanging individual model components. Other compelling reasons for evolution to a common software infrastructure include the move toward fundamentally new computer architectures that will need to be adapted to; another could be enhanced opportunities to exploit high-end computing capabilities facilitated by this approach; and a third could be to facilitate data standards that allow users to easily analyze results from different models with a common set of visualization and analysis tools. Decisive cross-agency endorsement of this approach will be needed to allow the climate modeling and software engineering community to collectively design and test the infrastructure and to provide the resources to transition current major models to it. The adoption of such an infrastructure will facilitate interactions among scientists engaged in the full hierarchy of U.S. modeling efforts, thereby leading to their greater unification and coordination and allowing the climate model enterprise to better serve national needs and advance more efficiently.
It is important that this infrastructure should entrain major regional modeling efforts as well as global climate modeling centers, and be adaptable to both research-oriented and operational modeling, to facilitate cross-fertilization between these model types and their developer and user communities.
Computational Capabilities for Climate Modeling
As described in Chapter 10, in order to meet the climate data and information needs of decision makers and users, U.S. climate models will need substantially increased computing capacity in the coming 10-20 years. This capacity will be distributed over a range of models and applications, ranging from pilot simulations for model development to large ensembles of lower-resolution simulations to extremely long paleoclimate simulations to decadal global and regional simulations at the finest grid