Abstract: The NCEP-1, ERA-40, and 20CR reanalysis precipitation data were evaluated by comparing their means, interannual variations, linear trends, and correlations with the observations in China. The results indicate that on the average, the ERA-40 data agreed better with the observations than the other two reanalysis datasets although it underestimated precipitation slightly. Both the NCEP-1 and 20CR data overestimated precipitation obviously, the percentage deviations of annual precipitation of the ERA-40, 20CR, and NCEP-1 from the observations over China were -1.3%, 55.0% and 36.9%, respectively. The maximum precipitation deviation usually occurred in Southwest China, with a value more than 600 mm. Percentage deviations of annual precipitation of the ERA-40 and NCEP-1 showed some fluctuations since the mid-1970s while the 20CR’s showed stability over the whole period. Basically, all three datasets well described the interannual variation of annual precipitation over China, but their correlations with the observations were usually better in the eastern China than in the western China. Of them the ERA-40 exhibited a better correlation in most of China than the other two datasets, and the ERA-40 and 20CR described trends of annual precipitation in most of China better than the NCEP-1.

Key words: precipitation, reanalysis dataset, inter-comparative analysis