三种再分析气温资料在中国西部地区的可信度评价

The reliability evaluation of three reanalysis air temperature data in West China

再分析资料质量检验和可信度分析是其合理使用的必要前提,是提高气候变化研究成果可靠性的根本保证,为了评价NCEP-II、ERA-40和JRA-25三种再分析资料在中国西部地区的可信度,研究对比分析了2m气温产品的质量。结果表明,这三种再分析气温产品都能较好地反映中国西部地区气温的空间分布特征,在地形复杂区域与站点气温的差异比较大,而在地势相对平缓的地区这三种再分析资料都能提供高质量的气温产品。由于同化了地面观测资料,ERA-40、JRA-25气温产品的可信度相对较高,且能够提供更为详尽的大尺度气温变异性。总体上,ERA-40的质量优于其他两种再分析资料。

Quality test and reliability evaluation are prerequisites for reanalysis data to be used.To evaluate the reliability of NCEP-II,ERA-40 and JRA-25 reanalysis data used in West China,the study analyzed the quality of the 2-m temperature products.The three types of air temperature reanalysis data could well reflect the spatial distribution in West China.The difference in air temperature at stations of complex topography was relatively large while the three types of reanalysis data could provide high-quality air temperature data in flat areas.Air temperature data from ERA-40 and JRA-25 are more reliable and can reflect more detailed air variability in large scale because they assimilate the ground-based data.Overall,the quality of ERA-40 is better than the other two types of reanalysis data.