Three independent observed precipitation climatologies are used to evaluate the performance of six different General Circulation Models (GCM) control runs. Two of the observed climatologies consist of mean monthly global fields (JAEGER and LEGATES), while the third is a new land-only time series of monthly precipitation from 1951 to 1980 (CRU5180). The six models evaluated are from the GFDL, GISS, LLNL, OSU and UKMO.

Comparisons are undertaken of hemispheric means and mean seasonal cycles, and of the spatial pattern of mean monthly precipitation. A distinction is made between land-only and land and ocean fields. Of the models examined here, observed monthly precipitation over both ocean and land areas is best simulated by the high resolution UKMO model (UKMO-H) and least well by the OSU model. Of the low resolution models UKMO performs demonstrably better than GISS, GFDL and OSU, especially in its reproduction of hemispheric seasonal cycles. ¿American Geophysical Union 1991