【作者】 陶岚；

【导师】 顾松山；

【作者基本信息】 南京信息工程大学 ， 大气物理学与大气环境， 2006， 硕士

【摘要】 利用多普勒天气雷达资料探测中尺度气旋并开展临近天气预报,是多普勒天气雷达作为中小尺度灾害性天气监测工具的重要功能之一。随着多普勒天气雷达作为探测强对流风暴天气的有效工具的推广应用,国内外研究人员发现中尺度气旋与暴雨、强风、冰雹、龙卷等灾害性天气密切相关。因此多普勒雷达提供的中尺度气旋信息将在强烈天气和龙卷风警报发布的准确性和及时性等方面显示出明显的优势。 本文首先讨论了中尺度气旋的天气学特征,尤其是径向速度分布特征及在不同背景场下多普勒雷达速度图像的特征。参考WSR-88D监测技术,介绍了以Rankine模式为基础的运用多普勒天气雷达资料探测中尺度气旋的三维识别技术,即通过对多普勒径向速度一系列的处理,寻找一维模式矢量,二维特征分量直到三维的大的对称的方位切变区域,从中提取中尺度气旋在多普勒雷达速度场中的重要特征信息。在充分借鉴国内外关于中尺度气旋识别算法的研究成果特别是NSSL的中尺度气旋探测算法的相关内容的基础上,结合多普勒天气雷达二次产品软件的特点,讨论了在该软件系统中中尺度气旋探测方法的改进之处。 在简要介绍了多普勒天气雷达二次产品软件系统的系统框架和模块的开发环境等相关内容后,我们在该系统的开发平台上,采用Visual C++6.0为应用程序开发工具,以动态链接库(DLL)的形式,采用上述改进后的中尺度气旋探测算法,完成了中尺度气旋识别模块的设计,并将该模块成功添加至系统中。增加了该识别模块的系统,可以生成中尺度气旋二次产品,从而可以确定强对流天气过程中的中尺度气旋的距离位置等相关参数,对强对流产生的严重灾害性天气进行有效的监测和预警。 通过对雷达资料进行回放的测试分析和两个个例的识别结果分析,本文对中尺度气旋识别模块的性能进行了讨论和总结,为进一步开展精确探测中尺度气旋的研究工作做好了准备。更多还原

【Abstract】 As an effective instrument of surveilling the meso-scale and micro-scale disastrous weather systems, one of the principal functions of WSR-88D using the volume scan data is to detect the mesocyclone and to make the weather forecast. With the increasing utilization of the WSR-88D as an effective tool of detecting severe convective whether, researchers both at home and abroad found that the mesocyclone had a close relationship with storm rainfall, strong wind, hail, tornado and other catastrophic whether phenomena. Therefore, the information of mesocyclone provided by WSR-88D has an obvious advantage in aspects of pre-alarming the severe whether and tornado accurately and in time.In this paper we firstly discussed the characteristics of mesocyclone especially its velocity features and radar echo characters on different wind backgrounds. Then we introduced the mesocyclone detection algorithm which is based on the Rankine module to extract significant attributes that characterized mesocyclones. Using Doppler velocity data the algorithm attempted to search for the pattern vectors initially, then to compose the features with qualified pattern vectors, and identify the mesocyclones at last. With these research results concerned with mesocyclone for reference, especially the related content of MDA, we presented an improved algorithm of mesocyclone detection needed in this Doppler Weather Radar Second Production software.After the brief introduction of the systemic framework and developing environment of this software system, we completed the design of the mesocyclone identification module in terms of DLL on the software platform with VC++ as the developing tool and added it into the software system successfully. The updated system can generate the mesocyclone second product which can help us to confirm the related references of mesocyclone to surveille and pre-alarm the severe disastrous whether more effectively, which are generated from convective weather systems.With the analysis of the results of the test experiment and two examples, we discussed andsummarized the quality of the mesocyclone identification module, which laid a solid foundation for further research of detecting mesocyclones more accurately.更多还原