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Study on Quantitative Precipitation Estimation by Polarimetric Radar Using Deep Learning

Advances in Atmospheric Sciences 2024年第6期41卷 1147-1160页

作者： Jiang HUANGFU Zhiqun HU jiafeng zheng Lirong WANG Yongjie ZHU State Key Lab of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China Meteorological observatory of Jiangxi Province Nanchang 330096China Hebei Meteorological Disaster Prevention and Environmental Meteorological Center Shijiazhuang 050021China School of Atmospheric Sciences Chengdu University of Information TechnologyChengdu 610225China

Accurate radar quantitative precipitation estimation(QPE)plays an essential role in disaster prevention and *** this paper,two deep learning-based QPE networks including a single-parameter network and a multi-parameter network are ***,a self-defined loss function(SLF)is proposed during *** dataset includes Shijiazhuang S-band dual polarimetric radar(CINRAD/SAD)data and rain gauge data within the radar’s 100-km detection range during the flood season of 2021 in North *** that the specific propagation phase shift(KDP)has a roughly linear relationship with the precipitation intensity,KDP is set to 0.5°km^(-1 )as a threshold value to divide all the rain data(AR)into a heavy rain(HR)and light rain(LR)***,12 deep learning-based QPE models are trained according to the input radar parameters,the precipitation datasets,and whether an SLF was adopted,*** results suggest that the effects of QPE after distinguishing rainfall intensity are better than those without distinguishing,and the effects of using SLF are better than those that used MSE as a loss function.A Z-R relationship and a ZH-KDP-R synthesis method are compared with deep learning-based *** mean relative errors(MRE)of AR models using SLF are improved by 61.90%,51.21%,and 56.34%compared with the Z-R relational method,and by 38.63%,42.55%,and 47.49%compared with the synthesis ***,the models are further evaluated in three precipitation processes,which manifest that the deep learning-based models have significant advantages over the traditional empirical formula methods.

关键词： polarimetric radar quantitative precipitation estimation deep learning single-parameter network multi-parameter network

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基于1.55μm激光雷达的雷暴风切变结构研究

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应用激光 2024年第1期44卷 86-96页

作者：白寒冰郑佳锋杜星车玉章中国民航宁夏空管分局宁夏银川750004 成都信息工程大学大气科学学院四川成都610225

低空风切变是公认的航空危险天气。为研究1.55μm激光测风雷达对低空风切变的探测能力,利用FC-Ⅲ型激光测风雷达数据对一次典型雷暴低空风切变进行细致分析。该雷达采用脉冲相干体制及全光纤结构,以混合扫描模式运行,其中包括:多普勒波... 详细信息

低空风切变是公认的航空危险天气。为研究1.55μm激光测风雷达对低空风切变的探测能力,利用FC-Ⅲ型激光测风雷达数据对一次典型雷暴低空风切变进行细致分析。该雷达采用脉冲相干体制及全光纤结构,以混合扫描模式运行,其中包括:多普勒波束摆动(DBS)扫描、4°与6°平面位置显示(PPI)扫描、沿跑道方向的距离高度显示(RHI)扫描、03#与21#起降通道(GP)扫描。结果表明,激光测风雷达混合扫描模式可在雷暴大风天气过程中探测到低空风切变的三个阶段,即环境风引起的水平风垂直切变、阵风锋引起的水平风切变、阵风锋后部雷暴出流引起的水平风垂直切变。风切变的垂直、水平结构特征与演变过程探测清晰。利用激光测风雷达混合扫描模式,预报员可至少提前5 min对此次风切变过程进行预警。

关键词：激光测风雷达混合扫描模式低空风切变结构特征

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Identification of Convective and Stratiform Clouds Based on the Improved DBSCAN Clustering Algorithm

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Advances in Atmospheric Sciences 2022年第12期39卷 2203-2212页

作者： Yuanyuan ZUO Zhiqun HU Shujie YUAN jiafeng zheng Xiaoyan YIN Boyong LI State Key Lab of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China School of Atmospheric Sciences Chengdu University of Information TechnologyChengdu 610225China

A convective and stratiform cloud classification method for weather radar is proposed based on the density-based spatial clustering of applications with noise(DBSCAN)*** identify convective and stratiform clouds in different developmental phases,two-dimensional(2D)and three-dimensional(3D)models are proposed by applying reflectivity factors at 0.5°and at 0.5°,1.5°,and 2.4°elevation angles,*** to the thresholds of the algorithm,which include echo intensity,the echo top height of 35 dBZ(ET),density threshold,andεneighborhood,cloud clusters can be marked into four types:deep-convective cloud(DCC),shallow-convective cloud(SCC),hybrid convective-stratiform cloud(HCS),and stratiform cloud(SFC)*** cloud cluster type is further identified as a core area and boundary area,which can provide more abundant cloud structure *** algorithm is verified using the volume scan data observed with new-generation S-band weather radars in Nanjing,Xuzhou,and *** results show that cloud clusters can be intuitively identified as core and boundary points,which change in area continuously during the process of convective evolution,by the improved DBSCAN ***,the occurrence and disappearance of convective weather can be estimated in advance by observing the changes of the *** density thresholds are different and multiple elevations are utilized in the 3D model,the identified echo types and areas are dissimilar between the 2D and 3D *** 3D model identifies larger convective and stratiform clouds than the 2D ***,the developing convective clouds of small areas at lower heights cannot be identified with the 3D model because they are covered by thick stratiform *** addition,the 3D model can avoid the influence of the melting layer and better suggest convective clouds in the developmental stage.

关键词： improved DBSCAN clustering algorithm cloud identification and classification 2D model 3D model weather radar

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1.55μm激光雷达高原机场下击暴流探测应用研究

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激光技术 2024年第3期48卷 318-326页

作者：牛向华黄轩朱文会郑佳锋唐顺仙任涛程振北京应用气象研究所北京100029 地理信息工程国家重点实验室西安710054 成都信息工程大学大气科学学院成都610225 民航青海空管分局气象台西宁810000 成都信息工程大学电子工程学院成都610225

为了探究激光雷达在湿下击暴流天气时的风场探测效果和低空风切变识别能力,采用多元资料结合具体事件进行理论分析和数据验证的方法,利用西宁曹家堡国际机场的测风激光雷达数据,结合地面观测记录,对2021-05-18的一次湿下击暴流过程进行... 详细信息

为了探究激光雷达在湿下击暴流天气时的风场探测效果和低空风切变识别能力,采用多元资料结合具体事件进行理论分析和数据验证的方法,利用西宁曹家堡国际机场的测风激光雷达数据,结合地面观测记录,对2021-05-18的一次湿下击暴流过程进行了分析和研究。结果表明,下击暴流具有复杂的风场结构,主体到达机场前,首先造成了超过14 m/s的外流,并与环境风耦合形成逆风切变辐合线,且最强外流区位于辐合线后侧1 km~2 km;下击暴流抵达跑道上空时,造成了地面辐散风场,辐散中心风速远小于外流边缘且垂直气流存在着剧烈变化,下击暴流共持续约10 min;测风激光雷达对雷暴云内部垂直气流分布、跑道区域下击暴流辐散风场的水平和垂直结构以及地面风场辐合线的形成和演变均有良好的识别效果,交互使用雷达不同探测模式和数据产品有利于机场低空风切变的监测和预警。该研究为激光雷达在下击暴流风切变预报和研究中的应用提供了参考。

关键词：激光技术测风激光雷达精细结构湿下击暴流低空风切变垂直气流

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深圳X波段双偏振相控阵雷达降水估测算法效果评估

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成都信息工程大学学报 2024年第1期39卷 61-71页

作者：余本超郑佳锋张扬刘黎平成都信息工程大学大气科学学院四川成都610225 中国气象科学研究院灾害天气国家重点实验室北京100081

为验证X波段双偏振相控阵雷达的降水估测能力,利用2020年深圳市X波段双偏振相控阵雷达探测资料和广州市S波段双偏振雷达探测资料,建立基于双偏振雷达参量强弱(即ZH、ZDR和KDP)的本地化混合降水反演方法,对不同降水使用最优的雷达参量进... 详细信息

为验证X波段双偏振相控阵雷达的降水估测能力,利用2020年深圳市X波段双偏振相控阵雷达探测资料和广州市S波段双偏振雷达探测资料,建立基于双偏振雷达参量强弱(即ZH、ZDR和KDP)的本地化混合降水反演方法,对不同降水使用最优的雷达参量进行定量降水估测,统计广东龙门县2016年雨滴谱观测资料,得到降水估测公式中的系数,分析不同时间、空间和降水强度下降水个例,利用本地化降水反演方法产生的定量降水估计结果与雨量计观测资料对比。结果表明,高时空分辨率的X波段相控阵雷达可以提高降水估测精度。X波段相控阵雷达在高时间分辨率下,其估测降水强度变化趋势和自动站观测的降水强度变化趋势一致,并且对降水强度小于40 mm/h的降水估测较为准确。在最大观测范围内,X波段相控阵雷达能观测到低层的气象信息,其降水估测的评估结果优于S波段雷达。X波段相控阵雷达对暴雨以下的降水估测更加准确,对暴雨以上的降水估测结果误差较大,可信度不高。

关键词： X波段相控阵雷达 S波段双偏振雷达定量降水估测

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基于云雷达资料的那曲对流云粒子相态识别研究

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气象科学 2024年第2期44卷 382-390页

作者：任涛郑佳锋杨吉曾正茂陈绍婕成都信息工程大学大气科学学院成都610225 中国气象局交通气象重点开放实验室南京210019 南京气象科技创新研究院南京210041 福建省气象信息中心福州350001 厦门市气象局海峡气象开放实验室福建厦门362012

本文利用第三次青藏高原大气科学试验的Ka波段云雷达资料,结合微波辐射计和探空资料,提出了以模糊逻辑算法为框架的相态识别方法,并利用那曲两个典型对流云个例对方法效果进行了分析。通过与前人方法的对比和对不同相态粒子回波强度谱... 详细信息

本文利用第三次青藏高原大气科学试验的Ka波段云雷达资料,结合微波辐射计和探空资料,提出了以模糊逻辑算法为框架的相态识别方法,并利用那曲两个典型对流云个例对方法效果进行了分析。通过与前人方法的对比和对不同相态粒子回波强度谱的统计,进一步验证了本文方法的可靠性。结果表明:利用雷达功率谱资料反演下落末速度并代替径向速度作为相态识别的参量之一,可提升对流云内粒子相态分类结果的合理性。零度层亮带和抬升凝结高度参量的使用,能够进一步优化相态识别的初步结果。固态云粒子的下落末速度远低于相同反射率因子的降水粒子,多模态/多谱峰的谱形态特征能够帮助识别混合相态粒子。

关键词：毫米波雷达相态分类功率谱青藏高原地区对流云

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Effect of crystal morphology of ultrahigh-nickel cathode materials on high temperature electrochemical stability of lithium ion batteries

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Journal of Energy Chemistry 2024年第1期88卷 327-335,I0008页

作者： Bi Luo Hui Li Haoyu Qi Yun Liu Chuanbo zheng Weitong Du jiafeng Zhang Lai Chen School of Metallurgy Engineering Jiangsu University of Science and TechnologyZhangjiagang 215600JiangsuChina National Engineering Laboratory for High-Efficiency Recovery of Refractory Nonferrous Metals School of Metallurgy and EnvironmentCentral South UniversityChangsha 410083HunanChina School of Materials Science and Engineering Beijing Key Laboratory of Environmental Science and EngineeringBeijing Institute of TechnologyBeijing 100081China

Higher nickel content endows Ni-rich cathode materials LiNi_(x)Co_yMn_(1-x-y)O_(2)(x>0.6)with higher specific capacity and high energy density,which is regarded as the most promising cathode materials for Li-ion ***,the deterioration of structural stability hinders its practical application,especially under harsh working conditions such as high-temperature *** these circumstances,it becomes particularly critical to clarify the impact of the crystal morphology on the structure and high-temperature performance as for the ultrahigh-nickel ***,we conducted a comprehensive comparison in terms of microstructure,high-temperature long-cycle phase evolution,and high-temperature electrochemical stability,revealing the differences and the working mechanisms among polycrystalline(PC),single-crystalline(SC)and Al doped SC ultrahigh-nickel *** results show that the PC sample suffers a severe irreversible phase transition along with the appearance of microcracks,resulting a serious decay of both average voltage and the energy *** the Al doped SC sample exhibits superior cycling stability with intact layered ***-situ XRD and intraparticle structural evolution characterization reveal that Al doping can significantly alleviate the irreversible phase transition,thus inhibiting microcracks generation and enabling enhanced ***,it exhibits excellent cycling performance in pouch-type full-cell with a high capacity retention of 91.8%after 500 cycles at 55℃.This work promotes the fundamental understanding on the correlation between the crystalline morphology and high-temperature electrochemical stability and provides a guide for optimization the Ni-rich cathode materials.

关键词： Single-crystalline Ultrahigh-nickel cathode High-temperature performance Phase evolution

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A Ka-band Solid-state Transmitter Cloud Radar and Data Merging Algorithm for Its Measurements

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Advances in Atmospheric Sciences 2017年第4期34卷 545-558页

作者： Liping LIU jiafeng zheng Jingya WU State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Chengdu University of Information Technology School of Atmospheric Sciences

This study concerns a Ka-band solid-state transmitter cloud radar, made in China, which can operate in three different work modes, with different pulse widths, and coherent and incoherent integration numbers, to meet the requirements for cloud remote sensing over the Tibetan Plateau. Specifically, the design of the three operational modes of the radar（i.e., boundary mode M1, cirrus mode M2, and precipitation mode M3） is introduced. Also, a cloud radar data merging algorithm for the three modes is proposed. Using one month＇s continuous measurements during summertime at Naqu on the Tibetan Plateau,we analyzed the consistency between the cloud radar measurements of the three modes. The number of occurrences of radar detections of hydrometeors and the percentage contributions of the different modes＇ data to the merged data were *** performance of the merging algorithm was evaluated. The results indicated that the minimum detectable reflectivity for each mode was consistent with theoretical results. Merged data provided measurements with a minimum reflectivity of -35 dBZ at the height of 5 km, and obtained information above the height of 0.2 km. Measurements of radial velocity by the three operational modes agreed very well, and systematic errors in measurements of reflectivity were less than 2 dB. However,large discrepancies existed in the measurements of the linear depolarization ratio taken from the different operational *** percentage of radar detections of hydrometeors in mid- and high-level clouds increased by 60% through application of pulse compression techniques. In conclusion, the merged data are appropriate for cloud and precipitation studies over the Tibetan Plateau.

关键词： data merging algorithm operational mode Ka-band radar cloud Tibetan Plateau pulse compression technique

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Characteristics and Possible Formation Mechanisms of Severe Storms in the Outer Rainbands of Typhoon Mujigae(1522)

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Journal of Meteorological Research 2017年第3期31卷 612-624页

作者： Bingyun WANG Ming WEI Wei HUA Yongli ZHANG Xiaohang WEN jiafeng zheng Nan LI Han LI Yu WU Jie ZHU Mingjun ZHANG Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science &Technology College of Atmospheric Sciences Chengdu University of Information Technology/Plateau Atmosphere and Environment Key Laboratory of Sichuan Province Hainan Meteorological Observatory National Satellite Meteorological Center

To better understand how severe storms form and evolve in the outer rainbands of typhoons, in this study, we in- vestigate the evolutionary characteristics and possible formation mechanisms for severe storms in the rainbands of Typhoon Mujigae, which occurred during 2-5 October 2015, based on the NCEP-NCAR reanalysis data, conventional observations, and Doppler radar data. For the rainbands far from the inner core （eye and eyewall） of Mujigae （dis- tance of approximately 70-800 kin）, wind speed first increased with the radius expanding from the inner core, and then decreased as the radius continued to expand. The Rankine Vortex Model was used to explore such variations in wind speed. The areas of strong stormy rainbands were mainly located in the northeast quadrant of Mujigae, and overlapped with the areas of high winds within approximately 300-550 km away from the inner core, where the strong winds were conducive to the development of strong storms. A severe convective cell in the rainbands de- veloped into waterspout at approximately 500 km to the northeast of the inner core, when Mujigae was strengthening before it made landfall. Two severe convective cells in the rainbands developed into two tornadoes at approximately 350 km to the northeast of the inner core after Mujigae made landfall. The radar echo bands enhanced to 60 dBZ when mesocyclones occurred in the rainbands and induced tornadoes. The radar echoes gradually weakened after the mesocyclones weakened. The tops of parent clouds of the mesocyclones elevated at first, and then suddenly dropped about 20 min before the tornadoes appeared. Thereby, the cloud top variation has the potential to be used as an early warning of tornado occurrence.

关键词： strong typhoon rainband severe storm tomado Rankine Vortex Model

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毫米波云雷达距离旁瓣回波质量控制及效果评估

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气象 2022年第6期48卷 760-772页

作者：曾正茂郑佳锋吕巧谊杨晖蔡艺友福建省气象信息中心福州350001 厦门市气象局海峡气象开放实验室厦门362012 福建省灾害天气重点实验室福州350001 成都信息工程大学大气科学学院高原大气与环境四川省重点实验室成都610225 平和县气象局福建漳州363700

根据福建省平和县布点的毫米波云雷达实际性能特点,且针对业务运行出现的距离旁瓣回波问题,提出了改进的质量控制方法;并利用福建平和站2018年9月至2020年8月的观测资料,定量评估质量控制效果对云-降水探测的具体影响。结果表明:提出的... 详细信息

根据福建省平和县布点的毫米波云雷达实际性能特点,且针对业务运行出现的距离旁瓣回波问题,提出了改进的质量控制方法;并利用福建平和站2018年9月至2020年8月的观测资料,定量评估质量控制效果对云-降水探测的具体影响。结果表明:提出的质量控制方法能较好改善雷达探测结果,距离旁瓣回波被有效滤除。距离旁瓣回波显著影响雷达对空中云雨回波的探测,影响最大集中在两个宽脉冲模式的盲区以上起始高度附近,即1.50~2.28 km和3.63~7.74 km,且距离旁瓣回波出现频次随高度上升而逐渐下降;距离旁瓣回波主要会干扰雷达对中低空弱云的探测,会导致云底被低估、云顶和云厚被高估,三个云参数的平均误差分别可达-0.53、0.74和0.73 km。

关键词：毫米波云雷达距离旁瓣回波质量控制评估

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