Abstract:

Two rare snow storm weather processes occurred in January 2008 and January 2011 in Guizhou Province，in this paper，the actual status，possible causes and their influence of these two freezing weather processes were analyzed． Results show that in 2008，the impact of La Nina events，the abnormal development of Eurasian blocking high in Jannuary，sustained and stable atmospheric circulation， active low system over central and west Asia，continuously northward transportation of plentiful warm and moist air from the bay of Bengal and South China Sea ( India － Burma trough) ，further north position of the ridge line，the larger area and stronger intensity of Western Pacific subtropical，all these were main causes resulting in freezing disaster weather in January 2008 in Guizhou． The impact of La Nina events，the abnormal development of Eurasian blocking high sustained and stable atmospheric circulation，continuously northward transportation of plentiful warm and moist air from the bay of Bengal and South China Sea ( India － Burma trough) were still important causes of the disaster weather process in Jannuary of 2011 in Guizhou，but the subtropical high was weaker，the low system over central and west Asia was not so active，so the intensity and range were less than those in January 2008．

Key words: freezing weather, blocking high, subtropical high, southern branch trough, inversion

摘要：

2008 年1 月和2011 年1 月，贵州遭遇了历史罕见的低温雨雪冰冻灾害，这2 次灾害过程具有降温幅度大、持续时间长、影响范围广、冰冻灾害重等特点，对农业、交通、电力、通讯都造成了严重的影响，经济损失严重。文中分析了2 次灾害的实况、可能成因及其影响。结果表明: ( 1) 2 次冰冻灾害都受拉尼娜事件的影响; ( 2) 欧亚1 月阻塞形势的异常发展和大气环流形势持续稳定; ( 3) 中亚、西亚低值系统活跃，来自孟加拉湾和南海( 印缅槽) 的大量暖湿空气向北输送。西太平洋副热带高压脊线明显偏北、面积偏大、强度偏强等是造成2008 年1 月贵州雨凇灾害的主要原因。拉尼娜事件的影响和欧亚阻塞异常偏强以及印缅槽出现持续的大量暖湿空气的向北输送是造成2011 年1 月贵州雨凇灾害的主要原因。但2011 年1 月副高偏弱，中亚、西亚低值系统活跃也不如2008 年1 月明显，所以低温雨雪冰冻强度和范围都小于2008 年1 月。

关键词: 雨凇, 阻高, 副高, 南支槽, 逆温