河西走廊东部寒潮特征及典型个例分析  

Characteristics and Typical Examples of Cold Wave in Eastern Hexi Corridor

作　　者：杨梅 杨晓玲 李岩瑛 齐高先[3] 罗晓玲 聂鑫 YANG Mei;YANG Xiaoling;LI Yanying;QI Gaoxian;LUO Xiaoling;NIE Xin(Wuwei Meteorological Bureau,Wuwei 733000,China;Lanzhou Institute of Arid Meteorology,CMA,Lanzhou 730020,China;Tianzhu Meteorological Bureau,Tianzhu 733200,China)

机构地区：[1]武威市气象局,甘肃武威733000 [2]中国气象局兰州干旱气象研究所,甘肃兰州730020 [3]天祝县气象局,甘肃天祝733200

出　　处：《沙漠与绿洲气象》2021年第5期86-92,共7页Desert and Oasis Meteorology

基　　金：国家自然科学基金面上项目(41975015)。

摘　　要：利用1986-2015年河西走廊东部5个气象站逐日气温、大气环流特征量和2016年5月常规天气图、物理量场,分析河西走廊东部寒潮时空分布及与大气环流特征量的关系和2016年5月3次寒潮过程天气成因。研究表明:河西走廊东部寒潮频次由北向南减少,但中部最少;年际差异较大,总体呈下降趋势;主要出现在1-5月和10-12月,频次站次4月最多、6月最少,春季寒潮频次最多;寒潮最早出现在9月1日(永昌)、最晚出现在6月7日(乌鞘岭)。月寒潮频次与月亚洲、北半球的极涡面积和强度、北极涛动、亚洲经向环流和冷空气指数呈显著正相关,与北半球极涡中心纬向位置和强度、东亚大槽强度、西藏高原1和2指数呈负显著相关;前一月亚洲、北半球极涡面积和强度、北半球极涡中心强度、北极涛动指数对月寒潮预报具有良好的指示意义,使用多元回归建立寒潮月频次预报方程,通过α=0.1显著性检验。2016年5月3次寒潮天气均与极涡中心偏强有关,前期升温明显、高空强盛冷平流、地面冷高压强烈是造成3次寒潮天气的主要原因,500 hPa横槽转向南压造成的降温幅度比小槽东移更强、影响范围更广。Based on daily temperature,atmospheric circulation characteristics during 1986-2015 and conventional observation data and physical quantity fields in May 2016,the spatiotemporal variation of cold wave and the relationship between cold wave and atmospheric circulation characteristics,and the causes of three cold wave processes in May 2016 were analyzed in eastern Hexi Corridor.Research showed that the cold wave frequency decreased from north to south.The cold wave frequency showed a decreasing trend with large inter-annual variability.The cold wave occurred mainly from January to May and from September to December,it most occurred in April,and the least in June,and the spring frequency was the highest.The earliest cold wave appeared on September 1st(Yongchang),and the last cold wave appeared on June 7th(Wushaoling).The monthly cold wave frequency was positively correlated with the Asia and Northern Hemisphere Polar Vortex Area and Intensity Index,Arctic Oscillation,Asian Meridional Circulation and Cold Air Activity Index,but negatively correlated with the Northern Hemisphere Polar Vortex Central Latitude and Intensity,East Asian Trough Intensity Index and Tibet Plateau Region 1,2 Index.It showed that the Asia and Northern Hemisphere Polar Vortex Area and Intensity,Northern Hemisphere Polar Vortex Central Intensity and Arctic Oscillation Index of the previous month had a better indication for prediction of cold wave.Multiple regression forecast equation of cold wave monthly frequencies was established,and passed significance level test of=0.1.All of the three cold wave weather in May 2016 were related to the strong polar vortex center.Obvious increasing temperature in the earlier age,strong cold advection in upper air and cold high pressure on ground were main causes of resulting three cold wave weather.The 500 hPa transversal trough turning southward caused more powerful and wider influence range than that of moving eastward small trough.

关 键 词：寒潮 时空变化 环流特征量 冷平流 河西走廊东部 

分 类 号：P458.122[天文地球—大气科学及气象学]