摘要
选取石家庄市新一代天气雷达2009-2012年29个降水过程雷达二次产品数据(低层5个仰角及组合反射率因子)和加密自动站逐分钟降水资料,依据与雷达回波强度最相近及与自动站位置距离最近的原则,建立随时空变化的动态Z-I关系,来定量估测无自动站观测格点的降水量,从而实时获取高分辨率雷达估测降水资料;对雷达定量估测降水与自动站观测降水的空间分布进行了对比,利用交叉检验方法分析了雷达定量估测降水的误差,结果表明:该方法反演降水的平均误差较小,为—0.6mm·h^(-1),能较好地表现出降水的时空分布特征,显示出不同等级降水的面积和演变,具有反演40 mm·h^(-1)以上的强降水中心的能力,表明该方法具有业务应用价值,对强降雨灾害的评估具有指导作用。
Minutely rain data from the regional Automatic Weather Stations(AWSs) and composite reflectivity,the five lower-angles radar reflectivity from Shijiazhuang radar second products are used to estimate radar-based quantitative precipitation.Twenty-nine rain processes in 2009 — 2012 are selected.According to the principle of the most similar intensity to radar echoes and the nearest distance to the AWSs,a new approach for radar quantitative precipitation estimate based on dynamic Z-l relations varying with time and space is presented.Grid precipitation without observation is calculated from radar echo reflectivity using this method.A series of quantitative assessments ensure the quality of radar-based precipitation estimates.Horizontal distribution of the hourly estimated rainfall data has been visually vertified against the corresponding AWS rainfall reports.Cross validation is used to analyze the errors.The results show high quality of the radar-based precipitation estimates in terms of small errors,high correlation and hourly rainfall pattern and evolution,including rainfall extremes more than 40 mm ·h^(-1).Therefore,the approach of dynamic Z-I relations is shown valuable to be applied in meteorological operation and instructive for assessing severe rainfall disaster.
出处
《气象》
CSCD
北大核心
2015年第3期296-303,共8页
Meteorological Monthly
基金
河北省气象局科研项目(13ky04
10ky21
12ky25)
中国气象局业务项目(SH-2012-02-07)
石家庄市科技计划项目(12155443A)共同资助
关键词
雷达回波
二次产品
加密自动站
逐分钟降水
动态Z-I关系
误差分析
radar echoes
second products
automatic weather stations(AWSs)
minutely rain data
dynamic Z-I relations
errors analysis