and criticism for their ability to serve their users. In some cases, the DAACs were criticized by implication as a result of reviews of EOS or EOSDIS. However, the DAACs have never been systematically assessed as components of a comprehensive data and information system. NASA has initiated such an assessment through a "recertification" process, which is being conducted in two stages. The first stage, an external peer review of the DAACs, has been conducted under the auspices of the National Research Council's (NRC's) Committee on Geophysical and Environmental Data (CGED). This report gives the results of that peer review, the first that the DAACs have ever undergone. The second stage of the recertification process will be conducted by a NASA panel, which will evaluate the results of the peer review in the context of NASA's programmatic and budgetary priorities. NASA management will then decide whether to recertify, place on probation, or close individual DAACs.
Each DAAC manages a different kind of scientific data—atmospheric, oceanic, solid-earth, polar, biospheric—and serves a unique blend of user communities. Because no single committee has the appropriate composition to review all the centers, seven review panels were established to conduct the site visits. The DAACs reviewed are located at the Goddard Space Flight Center (GSFC), Langley Research Center (LaRC), Earth Resources Observation Systems (EROS) Data Center (EDC), Alaska Synthetic Aperture Radar (SAR) Facility (ASF), Jet Propulsion Laboratory (JPL; Physical Oceanography DAAC [PO.DAAC]), National Snow and Ice Data Center (NSIDC), and the Oak Ridge National Laboratory (ORNL). (At NASA's request, the Socio-Economic DAAC [SEDAC] located at the Consortium for International Earth Science Information Networks [CIESIN] was not reviewed.) The CGED established the criteria for review and provided the panels with similar agendas and briefing materials so that the site visits would be conducted as uniformly as possible. A description of the study process is given in the Preface to this report.
In this report the CGED does not recommend whether or not any DAACs should be closed or placed on probation. Rather, based on the criteria for review listed in Appendix B, the committee and its panels commend the DAACs' successes and identify issues that require greater attention, with the overall goal of improving the DAACs' ability to serve their users. EOS is a science program that is designed to serve scientists. Thus, the CGED review focuses primarily on how well the DAACs serve the scientific community and secondarily on other types of users. Finally, because the DAACs exist as part of a system rather than as independent entities, the committee also addresses overarching issues regarding the DAACs as components of EOSDIS. (In keeping with its charge, the committee evaluated the DAAC's performance against their mission, but not against alternative ways of achieving the same goals. Similarly, the committee did not review EOSDIS as a whole, or the role of EOSDIS in global change research. The latter is addressed in NRC, 1998a.) This report was written at a time when technical difficulties, budgetary pressures, technological advances, and new management