data sets of relevance to the evaluation of Earth system models, available from NCAR.3 The two main objectives of this work are to (1) evaluate and assess often-used climate data sets and (2) provide “expert-user” guidance and advice on the strengths and limitations of selected observational data sets and their applicability to model evaluations. Another effort in its early stages is “Obs4MIPs,” which is an attempt to provide modeling groups with a limited collection of well-established and documented data sets that have been organized according to the CMIP5 model output requirements.4 More activities along these lines should be supported, because they are vital to the integrity of observational, modeling, and prediction studies of climate variability and change.
Climate data archives are scattered among federal agencies, laboratories, universities, and other repositories (also discussed in Chapter 10). While data catalogs exist, it is not easy for the scientific investigator or the decision maker to access and/or download the multidisciplinary data sets in various formats, subset them, “regularize” them (put them onto common grids, time spacing, units, etc.), and analyze them to advance understanding of the Earth system. The advances of information technology (e.g., OpenDAP3, Goddard Giovanni4) have enabled the remote analysis of subsets of the climate data. These information technology (IT) advances need to be brought to bear on the entire climate data holding, linking all the data repositories (regardless of agency) with a user-friendly nonexpert interface to the data that makes it easy and fast to find variables. This interface would support the ability for interactive standard analyses of the data sets and the download of subsets of the data and the analysis results. The formatting and gridding of the various data sets should not be an issue to the user. Such a national IT infrastructure for Earth system data could facilitate and accelerate advances in data display, visualization, and analysis and could be regarded as a natural philosophical extension of the community software infrastructure proposed in Chapter 10. Ideally, the development of such an infrastructure would be primarily community organized and well coordinated with model intercomparison efforts (which require exactly this kind of product, but then also generate model outputs on the same grid). It would be useful if an entity that has the ability to coordinate the efforts of multiple agencies, laboratories, and universities were to endorse this effort and help achieve an interagency agreement for how to support it. While other organizations could perhaps fill this coordinating role, the U.S. Global Change Research Program (Box 2.1) is the most obvious possibility.