摘要
利用高空地面观测资料和NCEP6h1次的1°×1°再分析资料,对2018年1月发生在河南省的2次区域暴雪过程进行对比分析。结果表明:2次暴雪过程背景形势场相似,都产生在500hPa高空槽东移、中层强盛西南气流形势下,配合低层偏东风切变线和地面冷空气的扩散作用。中层西南气流和底层偏东气流辐合的位置与大暴雪区域对应良好。降雪时整层大气湿度饱和,中低层具有弱的逆温层。同时地形的抬升作用,对局地特大暴雪的产生有贡献。2次过程降雪差异产生的主要原因是中层气流辐合位置不同。降雪过程中600~700hPa上辐合中心强度越强,对应降雪强度越大。垂直速度场上升运动区与主要降雪区域对应良好。700hPa暖平流与925hPa冷平流叠加区域即为产生大暴雪落区。风速辐合越大,对应降水越强。
The high-altitude and ground observation data and the 1°×1 ° reanalysis data of NCEP 6h were used to compare and analyze the two regional blizzard processes in Henan Province in January 2018. The results show that the background situation of the two blizzards is similar, and it occurs in the eastward movement of the 500 hPa high-altitude trough, and the middle-level strong southwest airflow, combined with the diffusion of the low-level easterly wind shear line and the ground cold air. The location where the mid-stream southwest airflow and the bottom eastward airflow are converged corresponds well to the large blizzard area. When the snow falls, the whole atmosphere is saturated with humidity, and the middle and lower layers have a weak inversion layer. At the same time, the uplifting effect of the terrain contributes to the occurrence of the local blizzard. The main reason for the difference in snowfall between the two processes is that the middle airflow convergence position is different. The stronger the intensity of the convergence center at 600-700 hPa during snowfall, the greater the snow intensity. The vertical velocity field rise motion zone corresponds well to the main snowfall zone. The superimposed area of 700 hPa warm advection and 925 hPa cold advection is the area where heavy blizzard falls. The greater the wind speed convergence, the stronger the corresponding precipitation.
作者
吕哲源
冀翠华
LV Zhe-yuan;JI Cui-hua(Kaifeng Meteorological Bureau,Kaifeng,Henan 475000)
出处
《安徽农业科学》
CAS
2019年第10期187-190,196,共5页
Journal of Anhui Agricultural Sciences
关键词
区域暴雪
低空急流
冷暖平流
物理量分析
河南省
Regional blizzard
Low-level jet stream
Cold and warmadvection
Physical quantity analysis
Henan Province
