【作者】 陈楠；

【导师】 顾松山； 徐芬； 陈钟荣；

【作者基本信息】 南京信息工程大学 ， 大气遥感科学与技术， 2008， 硕士

【摘要】 新一代多普勒天气雷达中的径向速度产品空间分辨率高达0.25km*0.25km,每6分钟进行一次体扫,由此反演出以雷达为中心到几十公里至一二百公里范围内不同高度的水平风向风速产品,其时空分辨率可达到6min*几十km,具有常规资料无可比拟的时空分辨率。自从我国多普勒天气雷达网投入业务应用以来,发现在降水过程中多普勒雷达速度回波图像有明显的特征。若能充分挖掘速度回波资料的特征,将其应用于天气预报中,将会大大地增加天气预报的效率和准确率。基于此,本文主要根据江苏南京雷达站2004-2007年收集到的多普勒天气雷达资料,并结合自动站的雨量信息及常规天气图等辅助信息,设计并统计分析了降水前径向速度回波及VWP产品在降水过程中的特征参量。论文主要包括四个部分:(1)降水前速度回波图像的特征及统计分析。介绍了非降水速度回波的辐合辐散特征,并用统计分析的方法得出非降水速度回波的辐合辐散特征对降水出现的预示性。(2)风廓线产品的特征及统计分析。介绍风廓线产品的特征,详细分析风廓线产品的可靠性及表征“湿度”变化的能力,研究降水前风廓线图中风向风速的变化与雨势大小的关系,粗略地提出“ND”厚度在降水预报中的预报指标。(3)春季大面积积层混合云降水过程VWP产品特征分析。细致研究了在南京地区春季大面积积层混合云降水前夕、维持增强和降水消亡阶段中风廓线产品表现出的不同特征,这些特征对今后该类降水的预报有指导意义。(4)个例分析。仔细分析了2007年4月22日南京市的一次春季大面积积层混合云降水过程的多普勒天气雷达速度回波和风廓线产品特征。更多还原

【Abstract】 The space resolution of radial velocity product in the CINRAD (China new generation Doppler weather radar) reaches 0.25 km * 0.25 km and the radar makes one volume scanning per 6 minutes, then the horizontal wind products of different height in the range of dozen kilometers to about 100 or 200 kilometers can be retrieved, whose spatiotemporal resolution can reach 6 min* dozen kilometers that conventional information amounts to less than the resolution. Since CINRAD network applied to operation, it is discovered that the velocity echo images of Doppler radar in the rainfall process have obvious characteristics. If the features of velocity echo data can be adequately dug out to apply to weather forecasting, the efficiency and accuracy of weather forecasting will be enhanced. As a result, mainly according to the Doppler weather radar data during 2004-2007 in Nanjing, and combined with the rainfall information of the automatic weather station and the routine weather charts, the characteristic parameters of radial velocity echo before precipitation and VWP products in the precipitation process are designed and statistically analyzed in the article. There are four sections mainly in the paper.(1) The characteristics and statistic analysis of radial velocity echo images before precipitation. The convergent and divergent features of non-precipitation are introduced, and it is concluded that the convergent and divergent features have strong indication for the appearance of precipitation by using the method of statistic analysis.(2) The characteristics and statistic analysis of VWP product. The features of VWP product are introduced, and the detailed analysis is made for the reliability of wind field and the ability in representing atmospheric humidity, then the relationship between the change of wind direction and speed and the rainfall intensity is also studied, meanwhile, the index of weather forecasting is roughly devised.(3) The characteristic analysis of VWP product in spring large scale rain course. The different characteristics at different stages of rainfall development (formation, development and dissipation) are studied in detail, which are meaningful for this kind rainfall in the future.(4) Case analysis. The detail analysis is made for the features of the velocity echoes and VWP product during a spring large scale rain course occurred in Nanjing on April 22 2007.更多还原