2011年7月14日低涡降水分析

摘要

利用MICAPS资料、JMA全球模式和NCAR/NCEP(1°×1°)再分析资料,对2011年7月14日发生在沈阳桃仙国际机场的中尺度切变线、低涡降水天气形势背景、物理量条件等方面进行数值模拟分析.结果表明,东北地区中低空急流下沉北抬,高空双急流中心逐渐拉近,这种风的垂直变化是暴雨产生的动力原因,同时低涡加强及其与副热带高压之间的南北向急流配合致使中高层西南气流源源不断地为降水提供水汽和不稳定能量,并有渤海低空急流配合时更有利于出现大范围强降水,强降水落区主要位于切变线及其北侧的风速辐合区；此次过程为明显的暖式切变线,其物理量场呈垂直分布；高低空配置利于上升运动维持,降水的水汽输送不仅依赖于对流层中低层的急流,还依赖于中层西南急流,雨强的增大与中高空急流风速辐合中心的建立有关.%By using the MICAPS data and JMA global model and NCAR/NCEP (1° × 1°) reanalysis data, an numerical simulation analysis was carried out on mesoscale shear line, vortex precipitation weather situation background, physical conditions in July 14, 2011 at Shenyang Taoxian International Airport. The results showed that the middle and lower tropospheric jet sink northward, high altitude double jet center gradually narrow , the vertical wind change is the power cause for the rainstorm. At the same time, vortex strengthen and jet configuration from south to north resulting in high layer southwest flow continuously provide vapor and unstable energy for precipitation, and the Bohai jets with more conducive to the emergence of large-scale precipitation, rainfall area located primarily on the north side of the shear line and the speed of convergence zone; this process is obviously warm shear line, the physical quantity field is vertical distribution. High and low altitude to upward motion to maintain configuration, precipitation water vapor transport is not only dependent on the middle and low troposphere jet, is also dependent on the middle-level southwest jet, rain intensity increases and upper-level wind speed convergence center established.