雷达VAD风廓线资料质量控制研究

Quality Control and Assessment of VAD Wind Profile of Doppler Weather Radar

多普勒天气雷达VAD(Velocity Azimuth Display)风廓线资料可以提供高时间分辨率的高空风场信息。本文针对中国雷达VAD风廓线资料,设计发展了面向资料同化应用的NMIC(国家气象信息中心)质量控制方案,该方案改进了NCEP(国家环境预报中心)方案中存在的问题。利用2020年2—8月的L波段秒级探空风场资料,分别对比质量控制前、经过NCEP质量控制方案、以及经过NMIC质量控制方案的VAD风廓线资料,统计分析结果表明经过NMIC质量控制方案的VAD风廓线资料最接近观测,准确度最高,并且在各个高度上其偏差和均方根误差最小,充分说明了NMIC质量控制方案的有效性。相对背景场偏差分析表明,经过NMIC质量控制方案的VAD资料偏差和均方根误差最小,与背景场的偏差更接近高斯分布,更能满足资料同化的要求。本文的研究有助于推进VAD风廓线资料在数值预报科研和业务中的应用。

The Velocity Azimuth Display(VAD)winds provide wind field information with high temporal resolution.A quality control scheme,called the NMIC scheme,is developed for VAD winds from CINRAD Doppler radar,which improves the NCEP CQCVAD scheme.Compared with L-band sounding winds,the VAD data after the NMIC scheme is more accurate than those after the NCEP CQCVAD scheme and the data before quality control.The bias and root mean square error of the VAD data after the NMIC scheme are smaller than those after the NCEP CQCVAD scheme and the data before quality control at most height levels,which confirms the validity of the NMIC scheme.The VAD winds after quality control are also compared with the background.The distribution of the deviation between background and the VAD data after the NMIC scheme fits the Gaussian distribution better than the NCEP CQCVAD scheme.The results reveal that the VAD data after the NMIC scheme can meet the quality control requirements for data assimilation.This study would support and further improve the application of VAD winds in the numerical weather forecast.