AN OVERVIEW OF THE GLOBAL HISTORICAL CLIMATOLOGY NETWORK TEMPERATURE DATABASE

The Global Historical Climatology Network version 2 temperature databa se was released in May 1997. This century-scale dataset consists of mo nthly surface observations from similar to 7000 stations from around t he world. This archive breaks considerable new ground in the field of global climate databases. The enhancements include 1) data for additio nal stations to improve regional-scale analyses, particularly in previ ously data-sparse areas; 2) the addition of maximum-minimum temperatur e data to provide climate information not available in mean temperatur e 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 infrast ructure 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.