G - I
type: Concept

HCN
type: Concept
definition: The U.S. Historical Climatology Network (U.S. HCN) was compiled in response to the need for an accurate, unbiased, modern historical climate record for climate change research. The Carbon Dioxide Research Program of the U. S. Department of Energy and the National Climatic Data Center (NCDC) of the National Oceanic and Atmospheric Administration (NOAA) established a network of 1219 stations in the contiguous United States for the specific purpose of compiling a data set suitable for detecting and monitoring climate change over the past two centuries. This network, known as the U.S. Historical Climatology Network (U.S. HCN), and the resulting data set were initially documented by Quinlan et al. (1987) and made available free of charge through the Carbon Dioxide Information Analysis Center (CDIAC). The data presented in Quinlan et al. (1987) extended only through 1984. In 1990 NCDC and CDIAC revised and updated the HCN data records through 1987 (Karl et al. 1990). In addition, ! using the techniques of Karl et al. (1988), NCDC generated temperature files in which the biases introduced by urbanization effects were removed. The new revision 3 (Easterling et al. 1996) data represent the best available data from the United States for analyzing long-term climate trends on a regional scale and may be used for studies attempting to determine the climatic impacts of increased concentrations of greenhouse gases. The data for most stations extend through December, 1994, and a majority of the station records are complete for at least 80 years. Unlike many data sets that have been used in past climate studies, these data have been adjusted to remove biases introduced by station moves, instrument changes, time-of-observation differences, and urbanization effects. Source and Scope of the Data: One of the objectives in establishing the U.S. HCN was to detect secular changes of regional rather than local climate. Therefore, only those stations that were not believed to be influenced t…
in scheme: projects