efforts in developing and using coupled ocean-atmosphere models for seasonal to interannual prediction, with its primary focus on the El Niño/Southern Oscillation phenomenon. The Working Group on Coupled Modeling (WGCM) has coordinated coupled ocean-atmosphere models that are primarily developed and used for the study of decadal to centennial climate change projections. A subset of the WGCM, the Working Group on Ocean Model Development, has fostered the development worldwide of the ocean component of coupled models to improve the representation of the ocean component of coupled models.
The community as a whole, under the aegis of the WGCM and the WGNE of WCRP, with links to the International Geosphere-Biosphere Programme, comes to consensus on a suite of experiments, which they agree would help advance scientific understanding. The WGCM sponsors the Coupled Model Intercomparison Project (CMIP), a project that seeks to foster and coordinate the design and execution of simulations using models around the world that are subjected to a common experimental protocol. Meehl and Bony (2011), Stouffer et al. (2011), and Doblas-Reyes et al. (2011) describe the current protocol and how it has evolved. All the major modeling groups participated in defining the experiments and protocols and have agreed to the CMIP5 suite2 as a sound basis for advancing the science of secular climate change, assessing decadal predictability, and so forth (Taylor et al., 2012). The use of this common protocol is designed to facilitate the comparison of the various models used. Model output is freely available over the Web. The Program for Climate Model Diagnosis and Intercomparison (PCMDI), sponsored through the U.S. Department of Energy, has played a key role in archiving this model output and facilitating its wide public dissemination.
These common experiments have evolved significantly over the years. The first experiments were performed in the early 1990s with atmosphere-only models as part of the Atmospheric Model Intercomparison Project (AMIP). A key aspect of this early effort that set the tone for future success was an emphasis on making model output available for use by a wide community of users. This early AMIP effort then spawned a number of model intercomparison projects, including an Ocean Model Intercomparison Project, the Paleoclimate Model Intercomparison Project, and the widely known CMIP.
In addition to the output of such coordinated experiments, the various working groups serve as important mechanisms for exchange of information and ideas among modeling scientists around the world. U.S. scientists have benefited greatly from such interactions. These working groups sponsor internationally coordinated experiments
2 Currently ongoing at the time of this report.