中国区域ERA-40、NCEP-2再分析资料与观测资料的初步比较与分析

Preliminary Comparison and Analysis between ERA-40,NCEP-2 Reanalysis and Observations over China

再分析资料在气候变化研究中有着广泛的应用,但是再分析资料在不同时空尺度上的可信度能够影响到研究结果。作者就中国区域的月平均地表(2 m)气温和降水两种基本气候变量在空间分布及其变化趋势上对ERA-40和NCEP-2与观测资料之间的差异做了一些比较和分析,对两套再分析资料的可信度进行了初步的检验。结果表明:两套再分析资料基本上都能反映出中国区域的温度场和降水场的时空分布,尽管在中国西部,尤其是青藏高原地区的差异比较较大;再分析资料在东部地区的可信度高于西部,温度场的可信度要高于降水场,ERA-40可信度要高于NCEP-2。

The Reanalysis datasets are widely used in climate change research, but the reliability of the reanalysis datasets at different time-spatial scale can also impact the results of the study. An preliminary intercomparison of monthly mean surface 2 m temperature and precipitation are made between the ERA-40, NCEP-2 reanalysis and the observations to validate the reliability of the reanalysis over China. The results show that the temporal and spatial distribution of temperature and precipitation for the ERA-40 and NCEP-2 are similar with the observed counterparts, although some differences can be aware of in the west region of China, especially in Tibet Platearh In terms of reliability, the temperature is higher than the precipitation, the East than the West, and the ERA-40 than the NCEP-2.