双多普勒天气雷达反演大气三维风场的个例研究   总被引：7，自引：3，他引：7  

古金霞  顾松山  陈钟荣  裴宇杰 《南京气象学院学报》2005,28(6):833-839

根据笛卡尔坐标系下双多普勒天气雷达反演大气三维风场的理论，以2003年7月5日发生在安徽省的一次强降水过程为例，反演大气三维风场。结果表明：利用双多普勒天气雷达反演大气风场能够更加详细地反映出大气风场的三维结构。  相似文献   

A Study on Retrieving Atmospheric Profiles from EOS/AIRS Observations   总被引：5，自引：0，他引：5  

GUAN Li  ALLEN Huang  LI Jun 《Acta Meteorologica Sinica》2005,19(1):112-119

1. IntroductionThe development of global climate and weathermodels requires accurate monitoring of atmospherictemperature and moisture profiles, as well as the con-tents of trace gases and aerosols. It is quite difficultto monitor continuously these parameters on a globalscale.Until recently. AIRS (Atmospheric InfraredSounder) offers a new opportunity to improve globalmonitoring of temperature, moisture, and ozone distri-butions and changes therein. The high spectral resolu-tion (v/Δv ? 12…  相似文献   

Dynamical and Microphysical Retrieval from Simulated Doppler Radar Observations Using the 4DVAR Assimilation Technique   总被引：3，自引：0，他引：3  

XU Xiaoyong  LIU Liping  ZHENG Guoguang 《Acta Meteorologica Sinica》2005,19(2):160-173

Based on a cloud model and the four-dimensional variational (4DVAR) data assimilation method developed by Sun and Crook (1997), simulated experiments of dynamical and microphysical retrieval from Doppler radar data were performed. The 4DVAR data assimilation technique was applied to a cloud scale model with a warm rain parameterization scheme. The 3D wind, thermodynamical, and microphysical fields were determined by minimizing a cost function, defined by the difference between both radar observed radial velocities and reflectivities and their model predictions. The adjoint of the numerical model was used to provide the gradient of the cost function with respect to the control variables. Experiments have demonstrated that the 4DVAR assimilation method is able to retrieve the detailed structure of wind, thermodynamics, and microphysics by using either dual-Doppler or single-Doppler information. The quality of retrieval depends strongly on the magnitude of constraint with respect to the variables. Retrieving the temperature field, cloud water and water vapor is more difficult than the recovery of the wind field and rainwater. Accurate thermodynamic retrieval requires a longer assimilation period. The inclusion of a background term, even mean fields from a single sounding, helped reduce the retrieval errors. Less accurate velocity fields were obtained when single-Doppler data were used. It was found that the retrieved velocity is sensitive to the location of the retrieval domain relative to the radars while the other fields have very little changes. Two radar volumetric scans are generally adequate for providing the evolution, although the use of additional volumes improves the retrieval. As the amount of the observations decreases, the performance of the retrieval is degraded. However, the missing observations can be compensated by adding a background term to the cost function. The technique is robust to random errors in radial velocity and calibration errors in reflectivity. The boundary conditions from the dual-Doppler synthesized winds are sufficient for the retrieval. When the retrieval is mainly controlled by the observations in the regions away from the boundaries, the simple boundary conditions from velocity azimuth display (VAD) analysis are also available. The microphysical retrieval is sensitive to model errors.  相似文献   

散射计资料的风场神经网络反演算法研究   总被引：3，自引：0，他引：3  

林明森  宋新改  彭海龙  冯倩 《国土资源遥感》2006,(2):8-11,i0004

建立一种神经网络反演海面风场的算法。该算法以ERS_1/2散射计数据和欧洲中期预报分析风场(ECM-WF)的配准点数据作为神经网络训练和检验数据集。研究表明,该算法具有运行速度快和精度高等特点,反演的风速和风向与C波段第4模型(COMD 4)和ECMWF吻合较好。  相似文献   

透明矿物薄片鉴定的计算机检索方法     

彭媛媛  李世超  陈曼云  常丽华 《吉林大学学报(地球科学版)》2006,(Z1)

介绍计算机自动化实现透明矿物薄片鉴定检索的方法。利用薄片鉴定时显示的光性特征,建立矿物鉴定数据库。运用VB为该数据库编写检索程序,实现计算机自动检索鉴定矿物种类。最后以黑硬绿泥石为例介绍检索系统的使用方法。  相似文献   

基于季节分异的太湖叶绿素浓度反演模型研究   总被引：4，自引：0，他引：4  

乐成峰  李云梅  孙德勇  王海君 《遥感学报》2007,11(4):473-480

叶绿素浓度反演算法主要有经验方法、半经验/分析方法和分析方法,其中半经验/分析方法应用最为广泛。但是反演的模型以及模型中的参数和反演精度都随着水体中叶绿素浓度的变化而改变。不同的季节水体中叶绿素浓度不同,水体反射光谱曲线特征和与叶绿素浓度相关性较高的敏感波段也不一致,使得各季节选用的反演模型和模型中的参数也存在一定的差异。本文在对2005年1—10月份叶绿素a（Chla）浓度季节差异进行分析的基础上,对4—10月份同步测量的水体光谱数据分春、夏、秋三个季节进行分析,分季节建立叶绿素浓度反演模型,并对它们进行比较,旨在为各季节选择最佳的反演模型。研究结果表明：春季和秋季选用波段比值算法反演精度较高,其中对数模型,线性模型和一元二次模型都有较高的相关性;夏季选用微分算法较好,该算法所建立的三种模型均具有较高的相关性。  相似文献   

“6.12”华南局地暴雨中β和γ结构的双多普勒雷达反演试验     

周海光 《热带气象学报》2007,23(2):117-125

使用双多普勒雷达三维风场反演技术对2005年6月12～13日广东省梅州和汕头多普勒天气雷达探测到的华南局地暴雨资料进行了三维风场反演,对暴雨系统的中尺度三维动力结构进行了分析。此次暴雨主要是由中低层的中β和中γ尺度辐合线造成的,强回波带与速度辐合带有较好的对应关系。辐合线对暴雨的触发、维持、持续具有重要作用,随着辐合线的减弱消散,强回波带也逐渐减弱,地面降水也随之减弱。最后,给出了此次暴雨的三维动力结构模型。  相似文献   

多普勒雷达风廓线的反演及变分同化试验   总被引：6，自引：2，他引：6       下载免费PDF全文

李华宏  薛纪善王曼 杨明 《应用气象学报》2007,18(1):50-57

为了将雷达风场资料更好地应用到数值预报模式中, 使用VAD方法反演多普勒雷达风廓线并处理成标准的探空资料进行变分同化试验。结果表明: VAD方法反演的风廓线与探空实况对应较好, 验证了用VAD技术反演风廓线的可行性。用GRAPES-Meso模式的三维变分同化系统对雷达风廓线资料进行同化后, 风场的初始场明显改善, 降水强度和落区预报也有不同程度的改善。其中, 对6 h降水预报的改善明显优于对24 h的预报改善。另外, 在短时强降水预报中, 雷达风场资料的同化频率和同化窗口的不同, 对降水预报的改善情况也有所差异。在个例研究中, 同化间隔为1 h的方案6 h降水预报要优于同化间隔为3 h和6 h的方案, 同化窗口为3 h的试验方案6 h降水预报要好于同化窗口为6 h的试验方案。  相似文献   

标准化气象数据服务接口设计与实现     

许皓皓  姚日升  沃伟峰 《气象科技》2018,46(4):685-691

为统一气象应用系统数据对接方式,规范气象数据使用环境,以国省两级气象信息化行动方案为纲领,采用Spring Boot和Spring Cloud微服务框架,设计和开发了标准化气象数据服务接口。标准化气象数据服务接口遵循气象信息化标准体系,采集和加工各类气象数据后汇入气象数据资源池,统一通过RESTful API发布数据,为全宁波市气象应用系统提供标准化数据对接服务。该接口改变了应用程序直接读取数据库的旧模式,降低了应用系统的开发成本,同时加强了运维部门对各类气象数据访问的监控和管理。文章主要介绍了气象数据服务接口的设计和开发过程,并详细描述了开发过程中涉及的接口规范、业务流程和关键技术。  相似文献   

EFFECTS OF A CLOUD FILTERING METHOD FOR FENGYUN-3C MICROWAVE HUMIDITY AND TEMPERATURE SOUNDER MEASUREMENTS OVER OCEAN ON RETRIEVALS OF TEMPERATURE AND HUMIDITY     

贺秋瑞  王振占  何杰颖 《热带气象学报(英文版)》2018,24(1):29-41

For Microwave Humidity and Temperature sounder (MWHTS) measurements over the ocean, a cloud filtering method is presented to filter out cloud- and precipitation-affected observations by analyzing the sensitivity of the simulated brightness temperatures of MWHTS to cloud liquid water, and using the root mean square error (RMSE) between observation and simulation in clear sky as a reference standard. The atmospheric temperature and humidity profiles are retrieved using MWHTS measurements with and without filtering by multiple linear regression (MLR), artificial neural networks (ANN) and one- dimensional variational (1DVAR) retrieval methods, respectively, and the effects of the filtering method on the retrieval accuracies are analyzed. The numerical results show that the filtering method can improve the retrieval accuracies of the MLR and the 1DVAR retrieval methods, but have little influence on that of the ANN. In addition, the dependencies of the retrieval methods upon the testing samples of brightness temperature are studied, and the results show that the 1DVAR retrieval method has great stability due to that the testing samples have great impact on the retrieval accuracies of the MLR and the ANN, but have little impact on that of the 1DVAR.  相似文献