However, this fragmentation invites duplication of effort and suboptimal alignment of national climate modeling priorities with computational resources.
An additional weakness of the U.S. institutional structure is that modeling activities for long-term climate change are not well connected with the main U.S. operational center for weather and short-term climate prediction at NOAA’s NCEP. In some other countries, such as the United Kingdom, modeling activities for both short-term weather prediction and long-term climate are integrated within a single institution. In this arrangement the models used for weather prediction and climate projections share much of the same software infrastructure and physics, although the models used on the two time scales are not identical. As articulated in Chapter 11, there would be a significant potential for overall advancement in the United States if there were tighter integration between modeling activities across time scales. Two strategies would be (a) enhanced interactions between scientists that are developing and using models for long-term climate change, intraseasonal to decadal climate change, and for weather prediction and (b) development of a single unified modeling system for prediction on all time scales.
Finding 13.4: Some limitations of the current institutional structure are that most U.S. climate modeling centers are individually subcritical with respect to expertise and funding, it is difficult to attract talented young scientists into model development, and the separation of operational and research modeling efforts can be a barrier to advances.
THE WAY FORWARD
A national strategy for advancing U.S. climate modeling should optimize or modify existing structures while adding critical new ingredients, as supported by the lessons learned from previous reports on U.S. climate modeling (Chapter 2). The committee believes it is productive to focus on actions that develop a greater level of unification by combining high-level cross-cutting leadership with science-motivated grassroots efforts. Several key aspects of a national strategy that contributes to this focus are described below. This discussion applies both to core modeling efforts for global climate and to regional climate modeling activities.
Regular National Climate Modeling Forum
In a distributed modeling system, the various model development and applications or user groups need mechanisms to communicate progress, share results, and discuss