ECMWF Global Analyses 1979-1986: Circulation Statistics and Data Evaluation

The purpose of this technical note is to establish the climate record from global analyses for use in compiling climatologies which may then be used to validate the Community Climate Model or as a base for examining anomalies such as occur in association with El Nino-Southern Oscillation events. Known problems with the ECMWF data set and changes in the operational analysis-forecast system including those which have resulted in major changes in analysis characteristics with time are documented. A transformation of the data set into a form which makes it more readily available are described. Moreover, climatological average statistics have been computed and are similarly available, both on line at NCAR and, for the long term averages, in fiche at the back of this report. This report is the second in a series of three as part of a project to comprehensively evaluate data sets of global analyses from the U.S. National Meteorological Center (NMC) and the European Centre for Medium Range Weather Forecasts (ECMWF). The first, NCAR/TN-299+STR, reported on the NMC data set of global analyses. This second report deals with the ECMWF analyses, and the third report, NCAR/TN-301+STR, describes results from a detailed comparison of the two data sets.