京津冀两次深厚涡旋北上暴雨过程对比分析

Comparative Analysis of the Rainstorm Process of Two Deep Vortexes in Beijing, Tianjin and Hebei

利用中国气象局中国国家级地面站逐小时观测资料和加密自动站资料,以及NCEP再分析资料等,对京津冀两次深厚涡旋系统造成的大范围暴雨过程进行对比分析,比较两者的环流背景、影响系统及物理量条件。结果表明:(1)两次暴雨过程高低空均为深厚涡旋系统沿太行山和燕山山脉方向东移北上,但2016年暴雨过程影响的深厚涡旋系统为西南涡减弱消散后形成的新生华北气旋,2021年暴雨过程为西南涡直接沿太行山东移北上。(2)2016年过程的水汽输送更旺盛,配合更好的水汽辐合条件产生暴雨。(3)两次暴雨过程的不稳定能量高,配合上升运动将低层的水汽和能量向高层输送,高温高湿条件下触发对流,造成雨强较大的短时强降水。(4)两次暴雨过程均受地形影响,雨带走向与太行山和燕山基本一致,但2016年暴雨过程降雨量最大区域位于太行山“喇叭形”山谷及其附近,雨带更加偏西,过程降水量更大,2021年暴雨过程最大雨量分布在沿太行山外围。

Using the hourly observation data of the China Meteorological Administration’s China National Ground Station and the encrypted automatic station data, the NCEP re-analysis data were used to compare and analyze the large-scale rainstorm process caused by the two deep vortex systems in Beijing,Tianjin and Hebei,and the circulation background of the two was compared, affecting the system and physical quantity conditions. The results showed that:(1) The high and low altitudes of the two rainstorms were deep vortex systems moving eastward along the Taihang Mountains and Yanshan Mountains, but the deep vortex system affected by the process in 2016 was the nascent North China cyclone formed after the weakening and dissipation of the southwest vortex, and the process in 2021 was the southwest vortex moving directly north along the Taihang Mountains.(2) In 2016, the water vapor transport in the process was more vigorous, and with better water vapor radiation conditions, heavy rain was generated.(3) The unstable energy of the two processes was high,and the water vapor and energy of the lower layer were transported to the upper layer with the rising movement, and the convection was triggered under high temperature and high humidity conditions, resulting in short-term heavy precipitation with large rain intensity.(4) Both processes were affected by the terrain,and the rain belt trend was basically the same as that of Taihang Mountain and Yanshan Mountain, but the largest rainfall area of the process in 2016 was located in the“trumpetshaped”valley of Taihang Mountain and vicinity, the rain belt was more westward,the process precipitation was greater, and the maximum rainfall in the process in 2021was distributed along the outskirts of Taihang Mountain.