摘要
利用NCEP/NCAR 1°×1°日4次再分析资料,针对2011年7月3—6日四川盆地持续性暴雨过程的影响系统和各物理量作了分析研究。结果表明:暴雨过程中不断有低压短波槽东移南下,西太平洋副高西伸至高原边缘,形成了有利的大尺度环流背景。对流层高层的强辐散与中层低涡的配合,低层强劲的南风暖湿急流与北风干冷气流在四川盆地内交汇,促使西南低涡发展和维持。高低层辐合辐散、对流运动强烈,持续强劲的水汽输送为暴雨维持起到了重要作用,暴雨持续期间产生不稳定能量释放从而又造成强烈的对流活动。螺旋度对暴雨落区及维持有较好的指示意义,暴雨落区与该地区上空中低层正、高层负局地垂直螺旋度中心有较好的对应关系。
The influence system and various physical quantity of a persistent torrential rain process in Sichuan basin during 3-6 July 2011 is analyzed by using the 6-hour-interval reanalysis data with 1°×1° resolution from NCEP/NCAR. the results show that Sichuan Basin was influenced by continual low-pressure shortwave troughs, and western Pacific subtropical high shifted westward to the edge of the plateau, formed a favorable large-scale cir- culation background. The interaction of strong divergence of upper troposphere and Middle-level vortex, the strong southward warm and wet jet and the northerly dry and cold airflow interaction with each other in the Sichuan Basinin the lower troposphere, promote the development and maintenance of Southwestern Vortex. lower-level conver- gence and upper-level divergence, strong convection, persistent and strong Water vapor transport have significant effect to the maintenance of torrential rain, unstable energy released during the rainstorm which in turn caused thestrong convective activity. The helicity has considerable forecasting significance for tenance,heavy rainfall area has a good correspondence with the positive vertical helicity in the lower-level andnegative vertical helicity in the upper-level.
出处
《贵州气象》
2015年第3期13-20,共8页
Journal of Guizhou Meteorology
基金
西南重大突发性自然灾害预警与防控技术研究与应用(2012 BAD 20B06)
关键词
西南低涡
持续性暴雨
低空急流
螺旋度
Southwestern Vortex
persistent torrential rain
lower-level jet
helicity
