| 摘要: |
| 铜仁市暴雪发生的频次低，2005年至今仅发生5次，因此准确的量级和落区预报难度较大。本文选取2004-2021年铜仁市出现的5场暴雪天气过程，就大尺度环流形势、高低空天气系统配置和物理量特征进行分析，找出暴雪环流形势以及物理量预报指标。结果显示：铜仁市暴雪发生时，500hPa中高纬为两槽一脊形势，我国东北地区-日本海低槽加深发展，中低纬孟湾附近有南支低槽系统东移；海平面场上贝加尔湖西部冷高中心强度为1060hPa，大于1030hPa的等压线线进入铜仁市。暴雪落区出现在500hPa高空槽和南支槽前、700hPa西南急流左侧或低涡切变线南侧、850hPa东北急流或东北风前部的风速辐合区内。暴雪日500hPa温度平均低于-16℃，700hPa温度为-2～-6℃，850hPa温度-6～-8℃，地面气温为0～-4℃，地面气温越低降雪持续时间越长。暴雪发生时大气中层700～500hPa上升运动明显增强,这可作为降雪增大的预示指标；散度场总体表现为低空辐合、高空辐散的特征，当辐合层次伸展更高时，有利于暴雪天气的持续；水汽通量散度辐合主要在850hPa，平均值为-3.6×10-6﹒g﹒cm-2﹒hPa-1﹒s-1； 500hPa比湿值≥1.5g/kg是暴雪发生的参考指标。 |
| 关键词: 铜仁市；暴雪;环流;物理量 |
| DOI： |
| 投稿时间：2022-02-22修订日期：2023-04-04 |
| 基金项目:铜市科研〔2020〕23号(冬季凝冻天气对铜仁市交通影响分析研究) |
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| The analysis of Atmospheric Circulation and Physical quantity Characteristicsof Snowstorm in Tongren |
| yangqun |
| (Tongren Meteorological Bureau of Guizhou Province) |
| Abstract: |
| Tongren blizzard frequency is low, 2005 to 2021 only five times, so the accurate snowfall and fall area forecast is difficult. This paper analyzes the large-scale circulation situation and physical quantity characteristics of five snowstorms in Tongren during 2004-2021, and finds out the snowstorm circulation situation and physical quantity forecast index. The results showed: Tongren blizzard circulation situation is in the high latitude two trough a ridge, northeast low trough deepened development-the sea of Japan, south branch low-value system coordination, blizzard have appeared in the 500hpa upper trough and southern trough or left the front of the southwest jet,700hPa southwest jet vortex shear line in the front of the south, 850hpa northeast rapids or northeaster wind speed convergence zone. The ground in the west of Lake Baikal cold high center of 1060hPa, strength is greater than 1030hPa isobaric line into the Tongren.The 500hPa temperature below 16℃ on average,700hpa temperature -2~-6℃, the 850hPa temperature -6~-8℃,the surface layer in 0~-4℃ in blizzard day. the lower the surface temperature the longer the duration of snow. The vertical ascent rate on 700~500hPa is obviously enhanced during the snowstorm, which can be used as an indicator of snowfall increase.The divergence field is expressed as Characteristics of convergence at low altitude and divergence at high altitude, When higher convergence level stretch, the blizzard weather last longer. The water vapor flux divergence convergence mainly in 850hPa. the average of -3.6×10-6﹒g﹒cm-2﹒hPa-1﹒s-1. The specific humidity value of 1.5g/kg is the reference index blizzard of Blizzard in the 500hPa. |
| Key words: Tongren; Blizzard; Circulation; Physical quantities |
