成都新一代天气雷达资料整编程序开发

作者利用Visual Basic 6.0作为编程工具开发的程序,对成都站新一代天气雷达资料进行整编,既能满足国家局对雷达资料共享的部分要求,又有利于日常资料的保存和使用.使用该程序可以提高资料整编效率,给雷达资料的保存带来了方便.     

新一代天气雷达个例资料整编系统设计

采用C语言和VC++6.0开发新一代天气雷达个例资料整编系统,能够对雷达基数据、雷达产品和雷达状态等信息每天自动异机整理存储,自动建立整编资料所需的各类文件夹和文件,使个例资料整编实现自动化、批量化、流程化和标准化。该系统可推广、移植到其它新一代天气雷达站。     

如何做好气候资料整编工作

陕西省 1 971 - 2 0 0 0年 30 a地面气候资料整编成果出版物中只有各类气象要素的 30 a累年统计值 ,而没有历年值及其他统计结果。随着用户对资料需求的不断变化 ,该出版物已经不能完全满足用户需要。台站可以根据需要 ,利用各类整编成果完成本站气候资料的整编工作。1　系统简介及运行前的准备工作1 .1　系统简介陕西省使用的整编程序是国家气象中心下发的《地面气象资料整编程序》又称 CDS30 ( CL I-MATE DATA SYSTEM) ,该系统能按国家气象中心颁发的《全国地面气候资料 ( 1 961— 1 990 )统计方法》对地面气象资料标准数据 ( W…     

雷达个例资料整编批处理技术与业务应用

在新一代天气雷达业务观测中,采用降水观测模式2,一天有近240个基数据和约有7200个数据产品。由于基数据和数据产品文件名与资料整编文件名格式上的差异很大,如果仅依靠人工进行整编,不仅文件多、信息量大,而且文件的重命名、校对审核尤为困难。系统地介绍了雷达个例资料整编的关键技术和解决方案,通过计算机实现了文件命名的自动批处理,采用向导式任务处理技术实现了雷达个例资料整编的自动化、批量化、流程化和标准化。     

气象资料信息化在我站的应用

我站气象资料信息化在气象站业务工作的应用,是从1978年初开始进行的。程序语言是ALGOL—60,电子计算机型号是DJS—6。实践表明,气象资料信息化对气象站业务建设是有作用的。下面介绍我们应用的范围及其效果。 一、整编本站气候资料 我站是1958年底建立的,积累了有近20年的气象资料,如何使用电子计算机进行快速整编呢?我们的步骤是:1.将历年气象资料在五单位纸带上进行作孔,使之成为电子计算机能接受的信息。作孔的项目有历年逐日平均气压、平均气温、最高气温、最低气温、日照、雨量、相对湿度等。2.编制整编程序。3.     

新一代天气雷达应用分析资料库系统的研制

新一代天气雷达应用分析数据库系统是在结合天气学和雷达气象学的有关知识的基础上开发出来的,能够满足气象台站建档整编天气过程资料工作的需要,也可为气象业务人员进行相关知识学习与科研提供一种平台。着重介绍了该系统的组成、技术要点和功能。     

新乡市气候资料电子累年簿的制作

利用Batcherenamer、ebookWorks等专用软件,对新乡市所辖8个县站1971～2000年气候整编资料进行整理、编译和链接处理,最终生成气候资料累年簿电子产品.电子累年簿具有占用存储空间小、易保存、资料安全和查找方便等特点.     

新乡市气候资料电子累年簿的制作

利用Batcherenam er、ebookW orks等专用软件,对新乡市所辖8个县站1971~2000年气候整编资料进行整理、编译和链接处理,最终生成气候资料累年簿电子产品。电子累年簿具有占用存储空间小、易保存、资料安全和查找方便等特点。     

新一代天气雷达资料下载与共享

就山东省气象局自行开发的主站宽带雷达资料下行传输程序做了详细的介绍，并给出了下载程序源代码。对省级雷达资料应用服务器的组建做了简单的介绍。     

气象资料整编程序的一种结构方案

江苏省气象局通过调查研究,规定全省各台站必须完成77个项目的资料整编工作,作为预报业务基本建设的一个重要内容。我区考虑到农业气象服务与试验研究的需要,把整编项目进一步扩大,涉及到的气象要素十多种,最基本的原始数据十多万个,对这些数据进行运算加工,如计算平均值、总和值、累积值、距平值、24小时变量值、要素差值(如e-T)等等,整编后一套资料总数据达几十万个,表格上千张,计算和抄写工作量都十分庞大,一般需要气象台站大家动手,苦干数年才能完成。 因此,利用电子计算机对气象资料进行快速整编是一项很有现实意义的工作。最近我们使用DJS-6机     

多普勒天气雷达与711天气雷达应用的对比分析

１引言７１１天气雷达是属于非相干雷达，只能探测回波的位置和强度等。而新一代多普勒雷达是一种新型的相干雷达，它可以测定散射体相对雷达的速度，在一定条件下反演出大气风场、气流垂直速度的分布以及湍流状况等。黑龙江省在２００１年１２月１８日通过３８３０多普勒天气雷达（以下简称３８３０天气雷达）的安装验收，于２００２年４月投入业务运行。目前黑龙江省各市（地）应用的是７１１天气雷达，在今后的预报、服务、人工影响天气等业务仍发挥作用。多普勒雷达与７１１雷达在分析与应用中有哪些差别呢？有必要进行分析和讨论。这里…     

Calibration of radar reflectivity measurements from the KMA operational radar network

A systematic procedure for calibrating system gain bias (so-called “calibration error”) of radar reflectivity measurements from the Korea Meteorological Administration (KMA) operational radar network is presented. First, the RJNI radar located at Jindo Island is calibrated by comparing with radar reflectivities simulated theoretically by a scattering algorithm using drop spectra collected by a disdrometer from June 19 to 29, 2009. Once the RJNI radar is calibrated, the reflectivity measurements from nearby radars are compared with the RJNI radar reflectivities to determine existing gain biases of nearby radars. This radar-radar calibration procedure was repeated with the other radars within the network. For isolating a system gain bias, echoes affected by partial beam blockage due to ground clutter and by attenuation due to precipitation were removed. The system gain biases of the RJNI and RPSN radars were ?3 and ?4.2 dB, respectively, during the experimental period. The RBRI and RDNH radars revealed relatively large biases, above ?8 dB. The other radars (RKSN, RGSN, RSSP, RKWK, RGDK, RIIA, and RMYN) revealed biases from ?6 to ?7 dB. Thus, the reflectivity measurements from all of the KMA radars were severely biased. New R-Z relations of R = 3.350 × 10^?2Z^0.624 (Z = 231.1R ^1.6) for stratiform and R=1.546 × 10^?2 Z ^0.714 (Z = 342.4R ^1.4) for convective precipitations were derived using disdrometer data. Using these R-Z relations, the radar-derived total rainfall amounts from the reflectivity measurements without calibration produced significant underestimations, compared to gauge measurements at about 80 sites, with a normalized bias of about ?56%. On the other hand, after calibrating the above system biases, the radar-derived rainfall amounts corresponded well with the gauge measurements, with a normalized bias of about ?3%. In conclusions, the radar reflectivity measurements from the KMA radar network are severely biased and the procedure presented in this study can be used to resolve the system gain biases.     

Comparison of the observation capability of an X-band phased-array radar with an X-band Doppler radar and S-band operational radar

An X-band phased-array meteorological radar （XPAR） was developed in China and will be installed in an airplane to observe precipitation systems for research purposes.In order to examine the observational capability of the XPAR and to test the operating mode and calibration before installation in the airplane,a mobile X-band Doppler radar （XDR） and XPAR were installed at the same site to observe convective precipitation events.Nearby S-band operational radar （SA） data were also collected to examine the reflectivity bias of XPAR.An algorithm for quantitative analysis of reflectivity and velocity differences and radar sensitivity of XPAR is presented.The reflectivity and velocity biases of XPAR are examined with SA and XDR.Reflectivity sensitivities,the horizontal and vertical structures of reflectivity by the three radars are compared and analyzed.The results indicated that while the XPRA with different operating modes can capture the main characteristic of 3D structures of precipitation,and the averaged reflectivity differences between XPAR and XDR,and XDR and SA,were 0.4 dB and 6.6 dB on 13 July and-4.5 dB and 5.1 dB on 2 August 2012,respectively.The minimum observed reflectivities at a range of 50 km for XPAR,XDR and SA were about 15.4 dBZ,13.5 dBZ and-3.5 dBZ,respectively.The bias of velocity between XPAR and XDR was negligible.This study provides a possible method for the quantitative comparison of the XPAR data,as well as the sensitivity of reflectivity,calibration,gain and bias introduced by pulse compression.     

TRMM星载测雨雷达和地基雷达反射率因子数据的三维融合

TRMM卫星上的测雨雷达(TRMMPR)探测资料分布均匀且具有很高的垂直分辨率,但灵敏度较低;地基雷达(GR)水平分辨率较高且具有较高的灵敏度,但其垂直分辨率低。通过将TRMM PR与GR反射率因子数据的三维数据融合,得到了更优的反射率因子图像。测雨雷达与地基雷达三维数据融合主要分为以下几步:测雨雷达与地基雷达数据预处理——如去杂波、衰减校正;测雨雷达与地基雷达时空匹配;选取和应用合适的三维图像融合算法;对融合后的图像进行效果评估。试验结果表明:融合后的图像不仅增大了信息量,更好地检测弱降水,还提高了空间三维(3D)分辨率,能更好地反映降水区域细节,且使得数据总体上具有更高的完整性和可靠性。此外,还将基于雷达资料估测的降水数据与地面雨量计数据进行对比,估计反射率因子数据融合在降水测量上的有效性。      

多普勒雷达与L波段雷达垂直风廓线对比分析北大核心

利用2012-2017年阜阳多普勒雷达与L波段雷达测风数据进行对比分析,统计两者的相关性和测量误差,进一步了解多普勒雷达风廓线产品的准确性和可信度。结果表明:两者测风结果一致性较好,风向和风速相关系数分别为0.97和0.94,标准差分别为19.5°和2.65 m·s^(-1)。多普勒雷达风速总体上在同一高度比L波段雷达风速偏小,两者风速相对偏差平均为24.48%;风速标准差随高度增高呈增大趋势,在降水期间对比差值小于非降水;风向标准差在7 km以下呈递减趋势,8 km以上有小幅增加趋势;风速相关系数随高度增加呈增大趋势,除低空偏低以外,其他高度相关系数均较高。     

秦皇岛地区雨滴谱仪和雷达探测的反射率因子差异分析研究

利用布设在秦皇岛市抚宁地区的OTT Parsivel激光雨滴谱仪和卢龙地区S波段天气雷达,对2017—2019年4—9月共23次降水过程进行了观测,并分析了基于雨滴谱参数(滴谱粒子数N(D)和粒子直径大小D₀)计算的雷达反射率因子Z_D和雷达探测的雷达反射率因子Z_R的差异Z_C。结果表明,N(D)主要集中在130～530个范围内,Z_C标准差随着N(D)的增大而逐渐减少;D₀主要集中在0.8～1.6 mm范围内,Z_C标准值在D₀<1.2 mm范围内随着D₀的增大而逐渐减少,D₀在1.2～1.6 mm范围内趋于稳定;Z_D主要集中在15～40 dBZ范围内,Z_C标准差在15～35 dBZ范围内随着Z_D值增大而减小。     

Relationship between cloud characteristics and radar reflectivity based on aircraft and cloud radar co-observations

Cloud properties were investigated based on aircraft and cloud radar co-observation conducted at Yitong, Jilin, Northeast China. The aircraft provided in situ measurements of cloud droplet size distribution, while the millimeter-wavelength cloud radar vertically scanned the same cloud that the aircraft penetrated. The reflectivity factor calculated from aircraft measurements was compared in detail with simultaneous radar observations. The results showed that the two reflectivities were comparable in warm clouds, but in ice cloud there were more differences, which were probably associated with the occurrence of liquid water. The acceptable agreement between reflectivities obtained in water cloud confirmed that it is feasible to derive cloud properties by using aircraft data, and hence for cloud radar to remotely sense cloud properties. Based on the dataset collected in warm clouds, the threshold of reflectivity to diagnose drizzle and cloud particles was studied by analyses of the probability distribution function of reflectivity from cloud particles and drizzle drops. The relationship between reflectivity factor (Z) and cloud liquid water content (LWC) was also derived from data on both cloud particles and drizzle. In comparison with cloud droplets, the relationship for drizzle was blurred by many scatter points and thus was less evident. However, these scatters could be partly removed by filtering out the drop size distribution with a large ratio of reflectivity and large extinction coefficient but small effective radius. Empirical relationships of Z-LWC for both cloud particles and drizzle could then be derived.     

济南边界层风廓线雷达与L波段雷达探空测风资料对比研究

采用统计、相关分析等方法,对2014年济南站边界层风廓线雷达观测资料和L波段雷达探空资料进行了长期时空变化规律的对比,进而研究了地面无降雨、有降雨时段两者的风向、风速数据的相关关系及差值。结果得出全年有降雨、无降雨时段两者的风向、风速总体一致性较好,相关性较高,并具有较好可比性和互补性的结论,对了解固定式边界层风廓线雷达探测的准确性,改进观测资料质量控制方法等具有很好的参考价值。     

Forecasting weather radar propagation conditions

Summary The increasing use of weather radar quantitative precipitation estimates, particularly in automatic applications such as operational hydrometeorological modelling or assimilation in numerical weather prediction (NWP) models, has promoted the development of quality control procedures on radar data. Anomalous propagation (AP) of the radar beam due to deviation from the standard refractivity vertical profile, is one of the factors that may affect seriously the quality of radar observations because of the increase in quantity and intensity of non-precipitating clutter echoes and consequent contamination of the estimated rainfall field. Another undesired effect of AP is the change in the expected radar echo height, which may be relevant when correcting for beam blockage in radar rainfall estimation in complex terrain. The aim of this paper is to study the use of NWP mesoscale forecasts to predict and monitor AP events. A nested 15-km grid resolution version of the MASS model has been used to retrieve refractivity profiles in the coastal area of Barcelona, near a weather radar and a radiosonde station. Using the refractivity profiles two different magnitudes were computed: the vertical refractivity profile of the lowest 1000 m layer and a ducting index which describes the existence and intensity of the most super-refractive layer contained in the lowest 3-km layer. A comparison between model forecasts and radiosonde diagnostics during a six-month period showed that the model tended to underestimate the degree of super-refraction, with a bias of 4 km⁻¹ and RMSE of 11 km⁻¹ in the 1-km vertical refractivity gradient. Further analysis of the data showed that a combination of previous observations and forecasts allowed to produce modified forecasts improving the original direct model output, decreasing substantially the bias, reducing the RMSE by 20% and improving the skill by 40%, beating also radiosonde observations persistence.