摘要
对 1 998- 0 7- 2 2 T0 8— 1 4发生于武汉附近的一次强暴雨过程的分析发现 ,这次强暴雨发生于南方暖区与北方冷空气脱离的孤立系统中 ,副热带经圈环流上升支是暴雨发生的大尺度背景场 ,它的低空入流和高空出流对大尺度雨区的生成与维持具有重要作用。边界层南风急流、低空西风急流和高空西风急流上下的耦合作用是强暴雨发生的重要原因。 92 5h Pa上边界层偏南风急流是暴雨区所需水汽的最大提供者和暴雨区对流不稳定能量释放的触发者 ,850 h Pa上低空偏西风急流的主要作用是建立和维持了暴雨区中低空的对流不稳定 ,2 0 0 h Pa上中纬高空西风急流的主要作用是建立和维持了暴雨区高空的条件对称不稳定 ,三者上下耦合使得中低空对流上升运动得以向上发展和加强 ,从而产生强暴雨。
Analysis on the storm rainfall in Wuhan from 08:00 to 14:00 on July 22,1998 illustrates that the process,with the background of an ascending branch of subtropical meridional circulation,is independent of south warm area and north cold air.Low inflow air and high outflow air play an important part in the forming and maintaining of the large scale rain region.The heavy rain is directly resulted from up and low coupling of boundary layer southerly jet,low westerly jet and high westerly jet.Southerly jet at 925hPa is the chief provider of water vapor and trigger of convective instability energy release;moreover,low westerly jet at 850hPa contributes much to the forming and maintaining of convective instability at middle and low level,while mid latitude high westerly jet to the forming and maintaining of symmetrical instability at high level.The storm comes into being owing to coupling of the three jets which develop and strengthen the convective and ascending air movement at mid low level.
出处
《南京气象学院学报》
CSCD
北大核心
2001年第3期308-314,共7页
Journal of Nanjing Institute of Meteorology
基金
国家重点基础研究发展规划项目"我国重大天气灾害的机理和预测理论的研究"G1 9980 40 90 7
中国气象局"九五"青年基金联合资助
