摘要
利用500 hPa、850 hPa等常规天气图资料和多普勒组合反射率、回波顶高、垂直累积液态含水量、径向速度、风廓线等天气雷达回波资料,对2011年7月29-31日辽宁省一次暴雨天气过程的多普勒雷达层状云降水回波特征进行分析,并分析了此次暴雨天气过程的多种雷达产品特征,探讨多种雷达产品对客观反映暴雨天气特征的可参考性,结果表明:此次暴雨降水地点主要发生在暖区、850 hPa切变附近,降水强度大、持续时间长;从雷达组合反射率图分析,地面大洼-辽中-法库-线有一个自西南向东北移动的降雨带存在,降雨带移动过程中,逐渐生成对流性云团产生暴雨,凤城-宽甸-线的降雨中心是由东南部发展的对流云团产生的;回波顶高近似均匀分布,空中液态含水量较小则表明这次过程的层状云降水特征明显;径向速度图表明7月30日20时降水产生时,径向速度出现相对大值区,其内有水汽辐合、质量辐合或较强的上升运动,强回波区域有弱的辐合气流;风廓线图可以看出在主要降雨时段,低层急流特征明显,最大风速可达27.3 m/s。
Based on the 500 hPa and 850 hPa conventional synoptic chart data and Doppler composite reflectivity, echo top, vertical integrated liquid water content, radial velocity and wind profilers radar echo data, the characteristics of Doppler radar echo of stratiform cloud precipitation in heavy rain process from 29 to 31 July, 2011 in Liaoning province were analyzed, the radar product characteristics of the heavy rain process was analyzed and the reference of radar products objective reflecting heavy rain weather characteristics was discussed. The results showed that： this heavy rain process happened mainly in the warm area, near 850 hPa shear, and the rainfall intensity was great and sustained a long time. Analyzing radar composite reflectivity graph, there is a rainfall zone moving from southwest to northeast in the line zone of Dawa-Liaozhong-Faku, which gradually generated convective clouds to produce heavy rains during the movement; the rainfall center of Fengcheng-Kuandian was produced by the southeast convective cloud cluster development; the distribution of echo top was approximate uniform, and the vertical integrated liquid water content was smaller, which indicated that the characteristics of stratiform cloud precipitation in this process was obvious; radial velocity diagram showed that when the precipitation occurred at 20： 00 July 30, the radial velocity appeared relatively great value area which included water vapor convergence, mass convergence or strong upward movement and a weak convergence flow in the strong echo area. Seen from the wind profile chart, the characteristics of low-level jet stream was obvious in the main rainfall time, and the maximum wind speed can reach about 27.3 m/ s.
出处
《气象与环境科学》
2014年第1期55-61,共7页
Meteorological and Environmental Sciences
基金
"十二五"辽宁省重点科技攻关项目"辽宁暖云人工增雨催化技术研究"(2011210001)资助
关键词
多普勒雷达
回波强度
层状云降水
Doppler radar
echo intensity
stratiform cloud precipitation
