摘要
该文以500 hPa环流作为关键影响因子,采用K-means动态聚类分型,将近10 a安顺降雪划分为平直气流型(Ⅰ)、南支槽型(Ⅱ)、多波动型(Ⅲ)3种主要形势。个例分析和合成分析表明:3种形势下降雪过程中相态变化、区域、持续时间等特点有所不同。合成分析还表明:3种形势在500 hPa环流上有明显的区别,Ⅰ型在高原东侧到贵州的气流基本平直,Ⅱ型从高原东侧到贵州有1个明显的南支槽,Ⅲ型在高原东侧到贵州有多个波动槽影响,在高原北侧沿河套地区和孟湾以东均有槽影响,形成阶梯槽。此外滇黔准静止锋的强度、影响区域、物理量以及垂直方向湿度配置、逆温等方面均有所区别:Ⅰ型湿层和上升区浅薄,有1℃左右逆温;Ⅱ型湿层较薄,Ⅱ型在贵州中部有3℃逆温范围较窄;Ⅲ型中低层有宽广的湿层,水汽和抬升条件配合较好,几乎没有逆温。
The height in 500 hPa was used as the key influencing factor,using K-means dynamic clustering method,the snowfall situations in Anshun was divided into three main situations:straight airflow pattern(Ⅰ),south branch trough pattern(Ⅱ),and multi-wave pattern(Ⅲ).Case analysis and synthetic analysis show that the characteristics of the phase change,region,and duration of the snow fall in these three situations were different.Synthetic analysis shows that the three situations have obvious differences in the 500 hPa height:patternⅠcases were basically straight from the east of the plateau to Guizhou,patternⅡhad an obvious south branch trough from the east of the plateau to Guizhou,and the patternⅢhad multiple wave troughs from the east of the plateau to Guizhou,forming a step troughs.In addition,the characteristics of Yunnan-Guizhou quasi-stationary front strength influence area,physical quantity,vertical humidity configuration and temperature inversion,etc.were different:the wet layer and the uplift zone were shallow in patternⅠ,with temperature inversion around 1℃;the wet layer was thinner in patternⅡ,having a narrow range of 3℃temperature inversion in the middle of Guizhou;in the middle and low layers there was a wide wet layer,and water vapor and uplift conditions were well coordinated in patternⅢ,there was almost no inversion temperature.
作者
韦琦
吴哲红
王兴菊
曾妮
蒙军
WEI Qi;WU Zhehong;WANG Xingju;ZENG Ni;MENG Jun(Zhenning Meteorological Bureau of Guizhou Province,Zhenning 561200,China;Anshun Meteorological Bureau of Guizhou Province,Anshun 561000,China)
出处
《中低纬山地气象》
2022年第3期74-79,共6页
Mid-low Latitude Mountain Meteorology
基金
贵州省气象局科研业务项目(黔气科登[2020]03-28号):安顺市近10 a降雪天气分析及个例库建立。
关键词
个例分析
聚类分析
环流分型
case analysis
cluster analysis
circulation pattern
