雷暴区域追踪矢量与雷暴单体追踪矢量融合临近预报研究

A vector blending study based on object-based tracking vectors and cross correlation tracking vectors

中文关键词:  TREC  TITAN  移动矢量  降水  临近预报

英文关键词:TREC  TITAN  Vector  Precipitation  Nowcast

中文摘要:

      雷暴追踪矢量的准确性是决定短时临近降水外推预报效果的关键。以TREC（Tracking Radar Echoes by Correlation）为代表的区域追踪和以TITAN（Thunderstorm Identifiation，Tracking，Analysis，and Nowcasting）为代表的单体追踪是追踪雷暴移动矢量的两种典型方法。TREC基于追踪格点雷达回波数据得到，能较好体现层状云降水和对流云降水系统的区域总体移动趋势；TITAN可以识别、分析雷暴的二维和三维属性，自动跟踪雷暴的移动速度和方向，形成雷暴单体移动矢量，能够更好地刻画小尺度雷暴单体的移动速度和方向。将TREC和TITAN两种移动矢量进行融合，生成新的外推移动矢量，既保留了TREC方法在刻画大尺度雷暴总体移动趋势信息方面的特长，又能充分发挥TITAN方法在刻画小尺度雷暴运动细节信息上的优势。融合试验表明，采用TREC和TITAN两种降水移动矢量融合的新技术，可以一定程度改进降水外推移动矢量场估计的准确度，提升降水落区和强度外推预报的准确度，对改善北京地区降水临近预报水平具有一定正效果。

英文摘要:

      The accuracy of thunderstorm tracking vector is the key to determine the effect of precipitation nowcasting. Regional tracking represented by TREC (Tracking Radar Echoes by Correlation) and object-based tracking represented by TITAN (Thunderstorm Identification,Tracking, Analysis, and Nowcasting) are two typical methods for tracking thunderstorm motion vectors. TREC is based on tracking grid radar echo data, which can better reflect the overall movement trend of both stratiform and convective precipitation. TITAN can identify and analyze two or three dimensional attributes of thunderstorms, automatically track the moving speed and direction of a thunderstorm, and form centroid-tracking vectors that can better describe the moving speed and direction of small-scale thunderstorm. In this paper, vectors of TREC and TITAN are blended to generate a new extrapolated moving vectors, which can retain the advantages of the overall information of large-scale thunderstorm movement while give full play to TITAN's advantages in describing detailed information of small scale thunderstorm motion. The blending experiment shows that the new technology can obviously improve the accuracy of precipitation vector fields by improving the forecast accuracy of precipitation area and intensity, and has positive effects on improving the skill of precipitation nowcasting in Beijing area.