A COMPREHENSIVE PRECIPITATION DATA SET FOR GLOBAL LAND AREAS

The data are here.

This data base offers an expanded and updated compilation of long-term station precipitation data, together with a new set of gridded monthly mean fields for global land areas. This data set contains 5328 station records of monthly total precipitation, covering the period from the mid-1800s to the late 1980s. The station data were individually tested and visually inspected for the presence of spurious trends, jumps and other measurement biases. The quality control procedure which was used to check the station records for non-climatic discontinuities and other biases are detailed in a technical report that accompanies this data base. The station data were interpolated onto a 4 degree latitude by 5 degree longitude uniform grid. Comparisons of these data with two other global-scale precipitation climatologies were done and are discussed in the technical report that accompanies this data base.

SOURCE AND SCOPE OF THE DATA

An expanded and updated compilation of long-term station precipitation data, together with a new set of gridded monthly mean fields for global land areas are provided in this subdirectory. This data set contains 5328 station records of monthly total precipitation, covering the period from the mid 1800s to the late 1980s. The station data were individually tested and visually inspected for the presence of spurious trends, jumps and other measurement biases. The quality control procedure which was used to check the station records for nonclimatic discontinuities and other biases is detailed in the report that accompanies these data files. Some of the problems which typically contribute to potential inhomogeneities in precipitation records are also described in the accompanying report. The station data were interpolated onto a 4 degree latitude by 5 degree longitude uniform grid. Comparisons of these data with two other global scale precipitation climatologies showed good agreement among the three global scale climatologies over the common areas in each set. Three different indices of long-term precipitation variations over the global land areas all indicate a general increase of annual precipitation since the 1940s, although a decline is evident over the last decade. There is some indication that the last few decades of the 19th century may have been as wet as the recent ones. An interesting feature of this study is the presence of relatively large differences in seasonal trends, with March-May and September-November becoming wetter in the last few decades. The December-February and June-August seasons exhibit smaller overall trends, although the northern winter season does exhibit large decadal-scale fluctuations.

REFERENCES

Eischeid, J.K., H.F. Diaz, R.S, Bradley, and P.D. Jones. 1991. A comprehensive precipitation data set for global land areas. DOE/ER-69017T-H1, TR051, United States Department of Energy, Carbon Dioxide Research Program, Washington, D.C.

Jon K. Eischeid and Henry F. Diaz
CIRES, University of Colorado
 and Environmental Research Laboratories
NOAA
Boulder, Colorado

Raymond S. Bradley
University of Massachusetts
Amherst, Massachusetts

Philip D. Jones
Climatic Research Unit
University of East Anglia
Norwich, United Kingdom