摘要
应用常规气象观测资料和NCEP 1°×1°再分析资料,对我国1961—2008年的南方极端低温冰雪典型过程进行了天气学分析。1961—2008年我国南方极端低温冰雪过程共发生了5次;这5次南方极端低温冰雪过程主要是受西风槽和南支槽、中层低涡和切变线、西南急流、地面强冷空气共同影响造成的;多股冷空气不断南下,前沿冷锋抵达黔滇地区、低层冷垫上空暖湿气流强盛、垂直结构逆温长时期维持是南方极端低温冰雪过程的重要特征;根据环流特征的不同可分为西南气流和偏西气流两种类型,前者降水和降温基本上是同时发生,形成雨雪冰冻天气,而后者一般是先降水、后降温,且后期降温剧烈,以低温冰冻天气为主。
Typical events of extremely low temperature and snow-ice weather in South China during 1961--2008 are analyzed using conventional weather observation data and NCEP data. During 1961--2008 there were 5 such typical events that affected by westerly trough and southern branch trough, low-level vortex and shear line, southwest jet and ground strong cold air. The essential characteristics of the Extremely Low Temperature and Snow-ice weather in South China are as follows： Cold air flows southerly and continuously and the cold front reaches to the region of Guizhou and Yunnan provinces, there is strong and ample warm wet air flow on cold wedge; long-lasting inversion layer could be seen in vertical structure. Because of different Characteristic of circulation, the forementioned typical weather events could be divided into two types which are southwester flow and west- northwester flow. For the foImer type, precipitation and temperature dropping basically occurs simultaneously resulting in snow-ice weather, while for the latter type, precipitation usually occurs before temperature dropping, and the temperature drops severely and results in cold surge frozen weather.
出处
《暴雨灾害》
2009年第4期321-327,共7页
Torrential Rain and Disasters
基金
国家科技支撑计划项目(2008BAC47B01)资助
关键词
极端低温冰雪天气
西风(南支)低槽
暖湿气流
冷空气垫(楔)
逆温层
Extremely low temperature and snow-ice weather
Westerly low trough
Warm wet flow
Cold wedge
Temperature inversion layer
