making abilities. The collection, archiving and accessing of Earth System data needs to support the analyses and products necessary to make these decisions. In general, the cost of archiving and providing access to data represents only a small fraction of the total resources invested in collecting or generating data.7 In addition, it is extremely difficult to estimate the present and future value of environmental or geospatial data to society. For instance, recently global atmospheric reanalysis of observations beginning about 1950 have proven to be an important climate assessment archive (Kalnay et al., 1996). It is difficult to appreciate the specific contributions that any data stream or data set makes, or might make, to long term climate monitoring or other environmental research requirements. In addition, data perceived to be of little use in the present could become quite valuable in the future as advancing technology increases our ability to make use of data. As discussed in more detail below, it is essential to actively engage the user community to help make these decisions. Effective stewardship of the nation’s investments requires preservation of what has taken substantial resources to collect.
Funding for Earth System measurements should include sufficient resources to archive and provide ready and easy access to these data for extended periods of time. In particular, at the outset of undertaking an activity which will generate data or model output, end-to-end data management needs to be planned and budgeted.
Many in situ data sets and the highest volume data sets (especially radar and satellite data) have been collected and funded in support of NOAA’s operational missions, with little initial provision made for long term preservation to support Earth system research, weather and climate prediction, and other societal benefits. Also, in the past, many data sets often had little use past their operational needs, while others were little used because of their spatial and temporal deficiencies. However, with new data assimilation methods and systems, most meteorological and oceanographic data can now be ingested by numerical models and used, for example, for model initialization and verification. These circumstances emphasize the vital importance of establishing an enduring, long term archive of environmental and geospatial data that is supported by the resources necessary to effectively meet these requirements, including resources for hardware and data managers. Assuring adequate and sustained levels of funding to archive and provide access to data remains a major ongoing challenge.
All data that are welldocumented, are of known quality, and represent systematic collections or characterizations of the state of the environment should be archived in their most primitive useful form.
Several of the considerations noted in the preceding section support this principle. First, observations of the state of the environment are generally expensive to obtain, and these costs far exceed archival costs. Second, it is impossible to anticipate all future applications of a data set, so a data set of uncertain present value may provide the key to some future scientific issue. Third, well calibrated data sets, or at least data sets with well defined error characteristics, are essential to long term climate monitoring and many other Earth System research requirements; this requirement implies a commitment to maintain records of successive improvements,