风廓线雷达在两次冬季多相态降水中的特征对比分析  

Comparative analysis on characteristics of wind profile radar data in two winter multiphase precipitation processes

作　　者：韩羽庭 陈昭伃 窦利军[2] 张曦 何佩仪 林冰 HAN Yuting;CHEN Zhaoyu;DOU Lijun;ZHANG Xi;HE Peiyi;LIN Bing(Safety Business Department of Daxing Air Traffic Control Center,North China Air Traffic Administration,Civil Aviation Administration of China,Beijing 102604,China;Meteorological Observatory of Daxing Air Traffic Control Center,North China Air Traffic Administration,Civil Aviation Administration of China,Beijing 102604,China;Meteorological Center of Southwest Air Traffic Administration,Civil Aviation Administration of China,Chengdu 610202,China;Fuzhou Early Warning Center,Fuzhou 350000,China)

机构地区：[1]民航华北空管局大兴空管中心安全业务部,北京102604 [2]民航华北空管局大兴空管中心气象台,北京102604 [3]民航西南空管局气象中心,四川成都610202 [4]福州市预警信息发布中心,福建福州350000

出　　处：《海洋气象学报》2025年第2期89-98,共10页Journal of Marine Meteorology

基　　金：2024年民航安全专业项目第396号项目。

摘　　要：利用欧洲中期天气预报中心0.25°×0.25°逐小时ERA5资料及北京大兴国际机场1号风廓线雷达资料,对比大兴国际机场2021年11月6—7日和2023年2月11—12日两次多相态降水过程,探究风廓线雷达在两次冬季多相态降水中的表现特征。结果表明:(1)风廓线雷达近地面风场偏东风建立、急流出现及中低空扰动均对冬季降雪临近预报起积极作用,低层冷空气增强对相态转换有一定指示意义,中高层暖湿气流爬升的强弱与降水强度变化有很好的对应关系。(2)降水强度和降水相态的变化均可在风廓线雷达探测的垂直速度上得到体现。两次过程的降雨时段在2.5 km以下有较大的正速度,随着降水相态由雨向雪转变,垂直速度发生锐减。(3)大气折射率结构常数(C_(n)^(2))和信噪比(signal-to-noise ratio,SNR)回波结构特征相似,两者均能反映降水强度变化。两次过程C_(n)^(2)对数值均在降水前1 h开始增大,C_(n)^(2)值越大,降水越剧烈,降水相态转为雨夹雪时,C_(n)^(2)对数值开始逐渐降低,高值区高度开始下降;两次过程SNR高值区主要集中在2.0 km以下,SNR结构越紧密、回波强度越大,降水越剧烈。(4)雷达探测高度受大气高层湿度的直接影响,可为降水强度的判断提供依据。Using the ERA5 hourly data(0.25°×0.25°)from European Centre for Medium-Range Weather Forecasts(ECMWF)and the data of No.1 wind profile radar at Beijing Daxing International Airport,two multiphase precipitation processes at Daxing Airport from 6 to 7 November 2021 and from 11 to 12 February 2023 are compared,and the characteristics of wind profile radar in the two winter processes are explored.The results are listed below.(1)The establishment of easterly winds near the ground wind field of wind profile radar,the emergence of jet streams and the disturbance in the middle and lower layers all play a positive role in the winter snowfall nowcasting.The enhancement of cold air in the lower layer has certain indicative significance for phase transition,and the strength of warm and humid uplift in the middle and upper layers corresponds well to the change of precipitation intensity.(2)Both precipitation intensity and precipitation phase transition can be reflected in the vertical velocity detected by wind profile radar.There are large positive velocities below 2.5 km during the rainfall period of the two processes,and the vertical velocity decreases sharply with the precipitation phase transition to sleet.(3)The echo structures of the atmospheric refractive index structure constant(C_(n)^(2))and signal-to-noise ratio(SNR)are similar,and both of them can reflect the change of precipitation intensity.The logarithmic values of C_(n)^(2)in both processes begin to increase one hour before the start of precipitation,and the higher the C_(n)^(2)value,the more intense the precipitation;with the phase transition to sleet,the logarithmic values of C_(n)^(2)gradually decline and the height of the high-value area decreases.The area of high SNR in the two processes is mainly concentrated below 2.0 km,and the tighter the SNR structure and the greater the echo intensity,the more intense the precipitation.(4)The radar detection altitude is directly affected by the humidity in the upper atmosphere,which can provide a basis for judging

关 键 词：北京大兴国际机场 风廓线雷达 相态转换 垂直速度 大气折射率结构常数(C_(n)^(2)) 信噪比(SNR) 

分 类 号：P412.25[天文地球—大气科学及气象学] P458.121