tific objectives and imperatives of the overall U.S. climate modeling enterprise would need to drive the operational details of any such facility.
Overall, an NCCF would be most attractive and least risky in an environment of sustained budget growth for climate science and modeling, which would allow it to be pursued in parallel with the other critical investments in climate modeling recommended in this report.
Why Not a Single U.S. Climate Modeling Center?
The approaches outlined throughout this report build on the current distributed system for U.S. climate modeling. They attempt to overcome the obstacles associated with a distributed system through frequent communication at U.S. modeling forums and the adoption of a common software infrastructure to support interlinked model development, execution, and analysis. We discussed a National Climate Computing Facility as a possible way to accelerate research into computational frontiers of climate science. Given this approach, a logical question to ask is: Why not simply move toward a single U.S. modeling center that could achieve these benefits under a “single roof,” replacing all the current climate modeling centers?
The committee believes such a move is undesirable at this time for several reasons:
• Current modeling institutions have a variety of missions supporting the needs of their sponsoring agencies, including operational prediction and data assimilation. It would be difficult to carry out those differing missions in a single, monolithic new institution without sacrificing the necessary focus.
• There is a recognized benefit to fostering multiple approaches to address critical topics. The downside of this approach is the potential for duplication of efforts, although the other efforts recommended in this report should reduce such duplication, e.g., the efforts to foster communication and the use of common infrastructure.
• It could be hugely disruptive, at least in the near term. Unless there were an extraordinary and sustained national interagency commitment to the process, the new center would not supplant the current centers, and further dilution of effort and resources might ensue.
The committee believes that a more distributed strategy embraces the philosophy of maintaining scientific diversity where appropriate while maximizing computational resource efficiency. This efficiency comes through the evolution to a common infrastructure, and the existence of a distributed computational capability including both