摘要
2009年3月19—20日新疆中天山出现暴雪天气,本文采用NCEP再分析资料计算和分析了这次暴雪天气过程的850～200 hPa范围内的垂直、水平螺旋度和总螺旋度,结果表明:暴雪区上空垂直螺旋度呈上负下正分布,有利于暴雪的发生;暴雪发生在低层水平螺旋度负值中心和整层螺旋度正值中心的东南边缘;总螺旋度强弱的变化反映了暴雪天气系统的趋势。分析表明螺旋度能较好地反映新疆暴雪天气的发展、维持状况及强弱程度,并对暴雪落区的预报有一定的指示意义。
The vertical, horizontal and perfect helicity from 850hPa to 200hPa of a snowstorm in Mar. 19-20, 2009 were analyzed by using NCEP data. The results showed that the vertical helieity over the snowstorm area presented negative in the upper and positive in the lower, which was suitable for occurrence of snowstorm; the snowstorm area located at the southeast verge of negative centre of lower horizontal helicity, and positive centre of horizontal helieity on whole level; the intensity variety of perfect helicity reflected the trend of snowstorm weather system. In conclusion, the helieity could manifest the development, continuance, intensity and the area of snowstorm.
出处
《沙漠与绿洲气象》
2010年第2期32-34,共3页
Desert and Oasis Meteorology
关键词
暴雪
垂直螺旋度
水平螺旋度
总螺旋度
snowstorm
vertical helicity
horizontal helicity
perfect helicity
