基于双偏振雷达的雨滴谱反演技术的对比分析

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  • 1. 成都信息工程大学电子工程学院,四川 成都 610225
    2. 灾害天气科学与技术全国重点实验室,中国气象科学研究院,北京 100081
    3. 中国气象局大气探测重点开放实验室,四川 成都 610225
    4. 中国气象局成都高原气象研究所/高原与盆地暴雨旱涝灾害四川省重点实验室,四川 成都 610072

网络出版日期: 2025-07-22

基金资助

国家重点研发计划课题(2022YFC3003901);国家自然科学基金项目(42105141U2142210);四川省中央引导地方科技发展项目(2024ZYD0175);中国气象科学研究院基本科研业务费专项基金项目(2023Z009);中国气象科学研究院科技发展基金项目(2025KJ023

Comparative Analysis of Raindrop Size Distribution Retrieval Techniques Based on Dual Polarization Radar

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  • 1. College of Electronic EngineeringChengdu University of Information TechnologyChengdu 610225SichuanChina
    2. State Key Laboratory of Severe Weather Meteorological Science and TechnologyChinese Academy of M eteorological SciencesBeijing 100081China
    3. Key Laboratory for Atmospheric SoundingChina Meteorological AdministrationChengdu 610225SichuanChina
    4. Institute of Plateau MeteorologyChina Meteorological AdministrationCMA/ Heavy Rain and Drought-Flood
    Disaster in Plateau and Basin Key Laboratory of Sichuan Province
    Chengdu 610072SichuanChina

Online published: 2025-07-22

摘要

基于双偏振雷达准确反演雨滴谱能够为研究大范围的降水微物理特性提供丰富的数据。为了进一步提高雨滴谱反演的精度,本文提出了基于六、七阶矩的双阶矩规范化雨滴谱反演算法(M6M7法),利用20225-6月河源站双偏振雷达及周围雨滴谱仪观测的6次降水过程数据,从整体统计、不同降水强度和不同雨滴大小三个角度,将新的雨滴谱反演算法与基于三、六阶矩的双阶矩规范化雨滴谱反演算法(M3M6法)、约束性Gamma雨滴谱模型反演算法(C-G法)进行对比,并对每个算法的反演结果进行研究分析。结果表明,M6M7法在小雨阶段[0 mm·h-1<降水强度(R≤5 mm·h-1]反演的滴谱参量误差是三种方法中最小的,随着降水强度的增大,除了液态水含量(LWC)、R误差增大,其余参量误差变化较小,在各个粒子端大部分参量误差在三种方法中最小,同时误差随粒子的增大变化较小。M3M6 法相较M6M7法增加了差传播相移率(Kdp)进行反演,虽Kdp对噪声敏感,但在大到暴雨(R>30 mm·h-1)环境中数据质量好,故在大到暴雨的反演具有较小的估测误差,且误差随粒子的增大(除LWCR)有所减小。在中雨(5 mm·h-1<R≤30 mm·h-1)阶段,C-G 法偏差中值接近于 0,但部分误差变幅显著,且随降水强度和粒子增大,误差呈先减小后增大的趋势,相对误差波动剧烈,估测结果稳定性较差。整体评估显示,M6M7 法估测各滴谱参量的偏差中值更接近于 0 且误差波动范围小,M3M6 法和 C-G 法误差波动范围大,总之,新提出的M6M7法相较于传统方法整体反演效果更优且稳定性突出,尤其在中小雨阶段优势明显,而 M3M6 法在大到暴雨环境中反演效果更佳,C-G 法则表现出反演反演不稳定的特点。融合M6M7法和M3M6法的综合算法,经初步验证能进一步提升雨滴谱反演精度。

本文引用格式

曾 静, 张 扬, 苏德斌, 董元昌 . 基于双偏振雷达的雨滴谱反演技术的对比分析[J]. 高原气象, 0 : 1 . DOI: 10.7522/j.issn.1000-0534.2025.00069

Abstract

Accurate retrieval of raindrop size distributionsDSDsbased on dual-polarization radar can provide substantial data for the study of precipitation microphysical properties on a large scale. In order to further im‐ prove DSDs retrieval accuracythis study proposes a new double-moment normalization method based on the sixth and seventh momentsM6M7 method),comparing it with the third and sixth moments methodM3M6 methodand the constrained Gamma model DSD retrieval methodC-G methodfrom three perspectivesover‐ all resultsdifferent rainfall intensitiesand different rainfall particle sizes. Utilizing data from six rainfall events observed by dual-polarization radar and surrounding disdrometers at Heyuan station between May and June 2022the retrieval results of each algorithm were analyzed. The results demonstrate that during light rain 0 mm·h-1<R≤5 mm·h-1),the M6M7 method exhibits the smallest parameter biases among the three methods. As rainfall intensity increasesbiases for most parametersexcept for the increase of liquid water contentLWCand rainfall rateR))remain relatively stablewith M6M7 consistently showing the lowest biases across different particle sizes and minimal fluctuation with the increase of particle size. Compared with M6M7 methodthe M3M6 method incorporates specific differential phase shift on propagationKdpfor retrieval. Although Kdp is noise-sensitiveit has good quality in heavy rainR>30 mm·h-1),resulting in smaller estimation biases for intense rainfall events and a decreasing trend in bias with larger particle sizesexcluding LWC and R. For moderate rain5 mm·h-1<R≤30 mm·h-1),the C-G method shows small median deviations yet significant fluctuations in certain parameters. With the increase of rainfall intensity and particle sizeits biases shows a trend of first decreasing and then increaseaccompanied by pronounced relative bias instability. Comprehensive evaluation results demonstrate that the M6M7 method consistently maintains median deviations approaching 0 across all DSD parameterswhile exhibiting significantly tighter error fluctuation ranges. In marked contrastboth the M3M6 method and C-G method display substantially wider bias variabilitywith their error distributions spanning broader numerical ranges and demonstrating less stable performance characteristics. The newly proposed M6M7 method technique demonstrates advantages over traditional approachesexhibiting enhanced comprehensive retrieval capabilities with regard to both accuracy and stabilityparticularly excelling in light-to-moderate rainfall with consistent accuracy. The M3M6 method proves more effective for heavy rain and stormswhile the C-G method demonstrates unstable retrieval characteristics. The final section demonstrates the retrieval performance of the algorithm integrating both M6M7 and M3M6 methodsverifying its capability to further improve raindrop size distribution retrieval accuracy.

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