摘要
利用500 hPa高度和温度信号场合成图的检验方法,分析了排名前40次广西重大低温雨雪冰冻过程的环流异常特征,研究结果表明:(1)利用冷湿指数定义这种方法选取过程具备对广西重大低温雨雪冰冻的影响程度进行评估的功能。(2)40个个例绝大部分过程500 hPa高度和温度信号场都有强的面积和强信号反应,正异常的表现更为突出。正异常一般表现的是高度场上的正值系统,也就是脊区,冬季高纬脊区发展通常配合冷平流的加强,冷空气堆积是广西持续低温雨雪冰冻过程出现的关键。(3)通过分析500 hPa高度信号场发现:乌拉尔山脊及前侧的横槽,贝加尔湖脊及前侧的东北横槽,及我国西北新疆一带不断分裂的小槽是广西产生低温雨雪冰冻天气的关键区域和关键因子。
Using 500 hPa average circulation signal field and average temperature signal field,we analyzed the circulation abnormal characteristics of the first 40 major cryogenic rain and snow processes.The results showed that(1)This method that uses cold and wet index to select process has the function of assessing the influence degree cryogenic freezing rain and snow in Guangxi.(2)Most signals of the 40 cases have strong area and strong signal reflection,having prominent positive anomalies.The anomalies are usually represented by a positive system in the high field,known as the ridge.The development of high latitude ridge in winter is usually combined with the strengthening of cold advection.Cold air accumulation is the key to the continuous freezing of low temperature rain and snow in Guangxi.(3)The signal field analysis can be divided into three categories.The weather system and its performance can be understood after the analysis of the signal field and high average field.The key areas and key systems for the cold and snow freezing weather in Guangxi are the Ural ridge and the front of transversal trough,the Baikal ridge and the front of northeast transversal trough,and the small trough in northwestern Xinjiang.
作者
唐熠
周秀华
郑传新
黎微微
TANG Yi;ZHOU Xiuhua;ZHENG Chuanxin;LI Weiwei(Guilin Meteorological Office of Guangxi,Guilin 541001;Guangxi Climate Centre,Nanning 530022)
出处
《气象》
CSCD
北大核心
2019年第10期1446-1456,共11页
Meteorological Monthly
基金
国家自然科学基金项目(41565005)
广西科学技术厅自然科学基金项目(2015GXNSFAA139243)
广西壮族自治区重点项目(桂气科2017206)
中国气象局预报员专项(CMAYBY2019-087)共同资助
关键词
低温雨雪
冷湿指数
信号场
关键区
cryogenic rain and snow
cold and wet index
signal field
key area
