An Overview of the Global Historical Climatology Network Temperature Database

The Global Historical Climatology Network version 2 temperature database was released in May 1997. This centuryscale dataset consists of monthly surface observations from ~7000 stations from around the world. This archive breaks considerable new ground in the field of global climate databases. The enhancements include 1) data for additional stations to improve regional-scale analyses, particularly in previously data-sparse areas; 2) the addition of maximum– minimum temperature data to provide climate information not available in mean temperature data alone; 3) detailed assessments of data quality to increase the confidence in research results; 4) rigorous and objective homogeneity adjustments to decrease the effect of nonclimatic factors on the time series; 5) detailed metadata (e.g., population, vegetation, topography) that allow more detailed analyses to be conducted; and 6) an infrastructure for updating the archive at regular intervals so that current climatic conditions can constantly be put into historical perspective. This paper describes these enhancements in detail. *Global Climate Laboratory, National Climatic Data Center, Asheville, North Carolina. Office of Climatology, Arizona State University, Tempe, Arizona. Corresponding author address: Thomas C. Peterson, Global Climate Laboratory, National Climatic Data Center, 151 Patton Avenue, Room 120, Asheville, NC 28801. E-mail: [email protected] In final form 11 August 1997. ©1997 American Meteorological Society