中国地基GNSS/MET水汽产品质量控制及与再分析产品的对比评估  

GNSS/MET Water Vapor Data:Quality Control Method and Comparative Analysis of Reanalysis Datasets

作　　者：远芳[1] 廖捷[1] 周自江[1] YUAN Fang;LIAO Jie;ZHOU Zijiang(National Meteorological Information Centre,Beijing 100081)

机构地区：[1]国家气象信息中心,北京100081

出　　处：《大气科学》2022年第5期1132-1146,共15页Chinese Journal of Atmospheric Sciences

基　　金：国家气象信息中心结余资金项目NMICJY202105;国家自然科学基金重大项目42090033;国家重点研究发展计划2017YFC1501801。

摘　　要：本文研究并提出中国地基全球导航卫星系统(GNSS)水汽产品的综合质量控制(CQC)算法。CQC算法由质量检查和综合决策两个环节组成。质量检查环节主要对待检观测数据与其参考数据的差异进行分析,包括界限值检查、考察时间一致性的临近点检查和低通滤波检查,考察空间一致性的邻近站检查、距平值检查和峰谷值检查,以及基于背景场的粗大误差检查等7个模块。每个检查标记出超过阈值的观测数据,随后利用综合决策算法对数据的标记情况进行综合评分,最终给出数据的质量控制码。基于质量控制后的数据,评估了中国第一代全球大气再分析产品(CRA)、ERA-Interim和ERA5等五套再分析数据在中国地区的水汽模拟效果。结果表明几套再分析资料模拟的大气可降水量(PWV)在冬季整体略高于观测,夏季则明显低于观测。在空间上,中国南方地区和西部地区模拟的PWV低于观测,这种情况在夏半年更加明显。相对于观测,CRA的平均偏差(O-B)为0.633 mm,均方根误差为3.650 mm。CRA相对于观测的误差略高于ERA5,但略低于ERA-Interim,明显优于JRA55和NCEP2结果。This study proposes a comprehensive quality control(CQC)algorithm for the Chinese ground-based navigation satellite system(GNSS)water-vapor products.The CQC algorithm consists of two sections—Quality check and comprehensive decision-making algorithms.The quality check algorithm consists of seven parts,namely,limit check to eliminate errors that exceed reasonable limits,buddy and low-pass filter checks for better time consistency,neighboring station check,anomaly and peak–valley value checks for better spatial consistency,and background check to identify the data that deviate from the background field for assimilation application.After each check,the data that exceed the threshold are identified,and the comprehensive decision-making algorithm is used to score the identified data and flag(correct,suspicious,or error)the data.Based on the quality-controlled observation data,the precipitable water-vapor simulation of five sets of reanalysis data,including China’s first-generation global atmosphere reanalysis(CRA)product,was evaluated.The results show that the simulated total water vapor of all the reanalysis data in winter is slightly higher than the observation in winter and significantly lower than the observation in summer.Spatially,the simulated water vapor content in southern and western China is lower than the observation,and this situation is more obvious in the summer half of the year.Relative to the observation,the average bias(O-B)of CRA is-0.633 mm,and the root–mean–square error is 3.650 mm.The deviation of CRA relative to the observation is slightly lower than ERA-Interim but slightly higher than ERA5,which is significantly better than JRA55 and NCEP2.

关 键 词：地基GNSS/MET水汽 质量控制 中国大气再分析资料 对比评估 

分 类 号：P426[天文地球—大气科学及气象学]