摘要
利用新疆乌鲁木齐和五家渠的双多普勒雷达同步观测资料与双多普勒雷达风场反演技术,结合多种气象资料(1 min间隔的地面自动站资料、探空资料和NCEP再分析场资料等),综合分析了2005年6月26日新疆乌鲁木齐附近一次强飑线过程。其流场特征是低层存在明显的辐合线,中层辐合,高层辐散。中低层的风场辐合使旧回波右侧(西南侧)一定距离处依次生成新回波并与旧回波合并,对流单体间的辐合线促使其迅速合并,是飑线发展的重要原因。对流单体间的合并是从中层开始的,然后扩展到低层。在低层对流单体合并后,飑线前部有一明显的辐合线,入流区、大的回波强度梯度区和弱回波区非常明显;同时,不同发展阶段的风场配置有明显的不同,上升气流和下沉气流在多单体风暴中同时存在。本次飑线过程中低层是东南风的入流气流,与对流带后部的西北风气流相遇后向上倾斜上升,在中高层形成飑前砧状云,这与国内外中纬度飑线的结构基本一致,但本次飑线过程只有前缘强烈的对流区,没有尾随的层状云降水。自动气象站、多普勒雷达及其反演的风场很好地揭示了该飑线的发生、发展、爆发过程及其回波和风场的空间结构特点。
A process of strong squall line（SSL） occurred near Urumqi in the Xinjiang Uygur Autonomous Region on June 26, 2005 is analysed using the dual-Doppler radar simultaneous observation data from the radars at Urumqi and Wujiaqu and the retrieval technology with a variety of meteorological data（including the automatic meteorological observation station data of one minute interval and sounding data,as well as the NCEP reanalysis data） integrated.The flow field of the process is characterized by the obvious convergence line lying in the lowlevels,convergence in the meddle-level and divergence in a higher level.It would be the main factors for the development of the SSL to generate successively new echos owing to the convergence in the lower levels and merge with the old one at a certain distance right to the old echo（on the southwestern side）,and the convergence line between the convection cells will even promote them to combine.The combination among convection cells starts from the middle-level and then extends to the lowlevels.The SSL shows an obvious convergence line after combining with the convection cells in the lowlevels,and the intlow zone,zone of intense echo grads and the zone of feeble echo section are very distinct. In the meantime,every developing phase show a different wind configuration from each other,with the updraft in the multi-cell-storm concurrent with the downdraft.Only the strong convection cell lies in the front of the SSL,without stratiform cloud precipitation followed.From the autonomous meteorological observation stations,dual-Doppler radars as well as the retrieval wind field,the occurrence,development and erupting processes of the SSL are well revealed and the spatial structures of the echos and their corresponding wind fields are brought to light as well.
出处
《气象学报》
CAS
CSCD
北大核心
2010年第2期224-234,共11页
Acta Meteorologica Sinica
基金
国家自然科学基金项目(40375008)
关键词
飑线
双多普勒雷达
三维风场
反演
Squall Line
Dual-Doppler radar
Three-dimensional Wind field structure
Retrieve
