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Archiving Data:
At the World Data Center-A (WDC-A) for Paleoclimatology

Robert S. Webb, David M. Anderson, and Jonathan T. Overpeck
NOAA National Geophysical Data Center, Boulder, Colorado

The Center

The World Data Center-A (WDC-A) for Paleoclimatology, established in 1992, is located at the U.S. National Oceanic and Atmospheric Administration (NOAA) National Geophysical Data Center (NGDC) Paleoclimatology Program, Boulder, Colorado. A primary mission of the data center is to provide the paleo- environmental data needed by the international research community to advance our understanding of Earth system dynamics at different timescales. The paleoenvironmental record represents a important source of observations: to understand the patterns and causes of decade- to century-scale environmental variability; to document the response of the climate system to large changes in forcing; to build a rigorous framework to evaluate the performance of the atmospheric, ocean, biosphere and trace-gas models used to study future change; and to construct the baseline of past natural environmental variability required to recognize human-induced global change. The WDC-A for Paleoclimatology is working with the International Geosphere-Biosphere Program (IGBP) Past Global Changes (PAGES) to coordinate a science-driven data management system for the acquisition, management, and distribution of all types of paleoenvironmental data. An important first step in this process will be to ensure that all published paleoenvironmental data is archived in a digital format and readily available to the international research community.

The Data

The WDC-A for Paleoclimatology archives paleo-environmental data in three forms: primary data (e.g, foraminifera or radiolarian counts and isotopic measurements), secondary data developed from the raw data (e.g., faunal percentages and isotopic ratios as a function of age), and tertiary information inferred from the primary and secondary data (e.g., PCO2, salinity, and sea surface temperature estimates). Also archived at the data center are modern calibration data needed to convert primary and secondary data into quantitative estimates of past climate, ocean, or biosphere conditions; time series of hypothesized climate forcing (e.g., solar, volcanic, trace gas, or astronomical changes); climate boundary conditions through time (ice extent and height, and sea ice extent); and output from atmosphere, ocean, and biosphere models. In addition to the actual data, information about the data, "metadata" is needed so that use and interpretation is made easy. Required and optional archival information for point or time series from an individual site and for mapped or gridded data (e.g., a map of sea surface temperature reconstructions or gridded data set from a paleoclimate model simulation) are listed in Table 1. Contributors also are urged to examine existing WDC-A data sets for examples of important archival information.

Archiving and Accessing

The WDC-A is committed to ensuring that data are available to all interested users and therefore distributes data in ASCII format on diskettes for DOS, UNIX, and Macintosh machines at the cost of reproduction and distribution. We are making a continued effort to try to accept contributions of digital paleoenvironmental data (and accompanying metadata) in any logical file format from Macintosh, DOS, or UNIX machines. A major advance in data archiving and accessing has been the establishment of an Anonymous ftp/Internet server that can be used to obtain or contribute data free of charge (see Figure 1 for details). Data distribution utilizing Internet or other linked wide area networks permits users to browse and download data available at the WDC-A for Paleoclimatology and to archive their own data. Datasets are currently available on a Sun workstation server in ASCII format, Paradox database when applicable, and as compressed archives for both DOS and Mac operating systems. Electronic data distribution, our preferred method, permits immediate access to all archived data sets as well as rapid distribution of updates and/or corrections to previously available data sets. The data center periodically distributes a newsletter describing new developments and new data sets. To receive information on the program or to be added to the mailing list contact Mildred England (phone: 303.497.6227; fax: 303.497.6513; Internet e-mail address:; World Data Center-A for Paleoclimatology, NOAA Paleoclimatology Program, National Geophysical Data Center, 325 Broadway, E/GC, Boulder, CO 80303 USA.

Table 1. Required and Optional Information for Data Archiving
Point or Time Series Data SetsMapped or Gridded Data Sets
Required Information
Data set nameData set name
LatitudeLatitude of grid points
LongitudeLongitude of grid points
Bathymetry/elevationTime period represented by data
Variable namesVariable names
Variable unitVariable unit
Data precisionData precision
Data formatData format
Contact information (mail, phone, email)Contact information (mail, phone, email)
Optional Information
Additional site informationAdditional site information
Brief desciption of data setBrief desciption of data set
Methods including referencesMethods including references
Chronostratigraphic informationChronostratigraphic information
Date of data generationDate of data generation
*Any other information that would make the data set useful.

D. M. Anderson (
J. T. Overpeck (
R. S. Webb (

Webb, R.S., D.M. Anderson, and J.T. Overpeck. 1994. Editorial: Archiving data at the World Data Center-A for Paleoclimatology. Paleoceanography 9:391-393.