Data centers are permanent facilities that focus on the long-term maintenance, disribution, and archiving of data and data products. There are 13 discipline-based World Data Centers in the United States, including centers for atmospheric trace gases, glaciology, human interactions in the environment, marine geology and geophysics, meteorology, oceanography, paleoclimatology, remotely sensed land data, rockets and satellites, rotation of the Earth, seismology, solar-terrestrial physics, and solid Earth geophysics. In addition to these World Data Centers, federal science agencies maintain nine national data centers, which provide access to an array of publicly available datasets. Scientists have always collected data, but the creation of data centers for improved archiving and distribution is a relatively recent and evolving activity. For example, U.S. government collection of weather observations began during the War of 1812, although weather records had been maintained in personal “weather diaries” in the United States as long ago as 1644 (Shea, 1987). In 1817 a system of weather observation was established at Weather Bureau land offices, and in 1942 a central Analysis Center was created to prepare and distribute computer weather forecasts, which later became part of the National Meteorological Center (Shea, 1987). The Weather Records Center in Asheville, North Carolina, was created by the Federal Records Act of 1950 (Public Law 754, 81st Congress; CFR § 506[c]), which combined the efforts of the Weather Bureau and the Air Force and Navy Tabulation Units. In 1957 the National Climatic Data Center was established during the International Geophysical Year and now maintains the World Data Center for Meteorology in Asheville. The National Climatic Data Center is the world’s largest active archive of weather data (NOAA, 2002).

The National Space Science Data Center was established as part of the National Aeronautics and Space Administration’s (NASA’s) Goddard Space Flight Center in 1966 and is primarily responsible for the long-term maintenance of space science data (NASA, 2002a). Distributed Active Archive Centers (DAACs) provide