洞庭湖地区一次持续性暴雨特征诊断分析
Diagnostic Analysis of a Continuous Rainstorm in the Dongting Lake Area
中文摘要：
利用国家站和区域站逐小时降水观测资料和NCEP再分析资料，分析了2017年6月29日—7月1日洞庭湖持续性暴雨过程。结果表明：1）暴雨发生在切变线南侧，急流轴左侧；副热带高压稳定维持，高低空急流耦合于洞庭湖区上空；高空槽波动，中低层低涡和切变线发展，有利于暖湿气流沿切变线辐合抬升；2）从水汽条件来看，印度洋水汽为主，其次是孟加拉湾—南海、太平洋地区；850 hPa水汽通量增强（减弱）对强降水来临（结束）具有较好指示意义，水汽强辐合带（中心）对暴雨落区有较好对应关系；3）洞庭湖上空的对流层中高层处于南亚高压脊线附近，高空辐散条件较好；中低空急流的演变对暴雨的发展有明显影响；垂直上升运动和辐合辐散配置与降水变化有较好的对应关系；4）列车效应与逆风区长时间维持与强降雨密切相关。
中文关键词：
暴雨，水汽，逆风区
KeyWords：
rainstorm, water vapor, upwind
Abstract：
In this paper, continuous rainstorm process of Dongting Lake Area from 29 June to 1 July 2017 was analyzed by using hourly precipitation observation data from national and regional stations and NCEP reanalysis data. The results showed that: 1)The rainstorm occurred in the south side of the shear line and the left side of the jet stream axis; The subtropical high maintained stable, making the high and low air jet coupling and staying over the Dongting Lake Area; The fluctuation of the upper trough, the development of the middle and lower vortexes and their shear lines were conducive to the continuous rainstorm weather caused by the convergence of the warm and wet air flows along the shear lines. 2) From the perspective of water vapor conditions, water vapor in the Indian Ocean was the most important source of water vapor transportation, followed by Bangladesh bending, South China Sea and the Pacific Ocean; The enhancement (weakening) of 850 hPa water vapor flux had a good indication significance for the arrival (end) of heavy precipitation; In addition, the strong convergence zone (center) of water vapor had a good correspondence with the rainfall area. 3) The upper troposphere over the Dongting Lake was near the ridge line of South Asia high. The evolution of middle and low level jet had obvious influence on the development of rainstorm. The vertical upward movement and convergence and divergence configuration corresponded well to precipitation changes. 4) The train effect and the long duration of upwind zone were closely related to the strong rainfall in the upwind area.