There is an emerging perception that the physics of the growing family of geophysical flow models is not receiving the continuing attention needed to make these tools more useful and accurate. In some cases the models have stagnated, changing little since their inception. Some of the reasons for this stagnation lie in the underlying science. For example, despite decades of intensive efforts by several science communities, adequate models of geophysical turbulence still do not exist. But some of the problem seems cultural; today’s modelers and users of model output seem less engaged with improving model physics than with the increasingly sophisticated numerics, graphics, and architecture of the model system and with using models rather than observations to study geophysical flows. As education and training in the atmospheric and oceanic sciences turn away from model physics, students increasingly see model outputs as truth without the healthy skepticism that should be inherent with these tools.
No model is or ever will be perfect. The atmosphere and ocean are inherently nonlinear, and their chaotic physical processes occur over a vast range of scales, making it impossible to simulate every physical process at every scale. But because these models are often used to predict future events, which can have immediate to long-range policy implications, it is imperative that their underlying physical processes be represented as robustly as possible. To ensure success in this regard, it is vital that the science of geophysical modeling garners the attention and support necessary to continue its improvement.
The National Academies’ Board on Atmospheric Sciences and Climate organized its 2004 summer workshop to explore and evaluate current efforts to model physical processes of coupled atmosphere-land-ocean (A-L-O) models (see Appendix A for the complete Statement of Task). Specifically, the parameterization of physical processes in A-L-O models was addressed, including associated errors, testing, and efforts to improve the use of parameterizations. During the workshop discussions, participants examined some intellectual and scientific challenges in modeling and highlighted the proposition that some of the key impediments to progress in representing physical processes are primarily cultural in nature. For reasons that may broadly have to do with the incentives and disincentives that exist in certain parts of the atmospheric and oceanic sciences, scientists in the field may be slipping into a mode of conduct in which the arduous and often unrewarding task of developing and rigorously testing new parameterizations is avoided in favor of