北极涛动对华南地区寒潮的影响  

Effect of Artic Oscillation on Cold Waves in Southern China

作　　者：李彩玲 余广昌 王华[2] 

机构地区：[1]佛山市气象局,广东佛山528000 [2]广东省气候中心,广东广州510080

出　　处：《广东气象》2016年第3期12-16,共5页Guangdong Meteorology

基　　金：佛山市气象局科学技术研究项目(201309)

摘　　要：利用1960—2010年(NCEP/NCAR)再分析资料和我国同期549个气象观测站的日最低气温与日平均气温资料,分析华南地区寒潮爆发次数、爆发路径与北极涛动(AO)的相关关系,并结合冬季大气环流异常研究了AO对华南寒潮过程的影响。结果表明:AO指数与华南寒潮爆发次数呈负相关;AO指数为正时,AO偏弱,寒潮爆发次数较少,中层东亚大槽偏弱,出现异常东南风,不利于冷空气向南扩散,对寒潮爆发起阻碍作用;当AO指数为负时,AO偏强,影响华南的寒潮偏多,中层东亚大槽偏强,出现异常西北风,有利于冷空气向南扩散,对寒潮爆发起加强作用。由于AO与寒潮的爆发次数有着较强的相关关系,在寒潮过程中冷空气的输送路径的确定可以为预报提供一定依据。AO与寒潮爆发路径分析结果表明,AO异常强年,低层冷气团输送异常,从蒙古出发折向日本,在日本南部转向华南地区输送,另一路冷气团由西伯利亚出发,到青海一带折向广西输送,并在广西区域折向华南地区输送,AO异常弱年并没有明显异常冷气团输送。With the NCEP / NCAR reanalysis data for 1960- 2010 and daily minimum and mean temperatures from 549 weather stations across China during the same period,we analyzed the correlation between the times of cold waves outbreaks and paths of outbreaks and the Arctic Oscillation（ AO） and studied its effect on the cold waves in southern China. The result is shown as follows. The AO index is negatively correlated with the times of cold waves outbreaks in southern China; when it is positive,the AO is weaker,cold waves have fewer outbreaks,a mid- level East Asian trough is weaker,and an anomalous southeasterly appears to make it hard for the cold air to spread southward,blocking the outbreak of cold waves,and when it is negative,the AO is stronger,the cold waves affecting the southern China are more frequent,the trough is stronger,and an anomalous northwesterly occurs to facilitate the southward spread of the cold air,strengthening the outbreaks of cold waves. As the AO is well correlated with the outbreak times of cold waves,the determination of cold air transporting paths during cold waves can be supportive to forecasting.As shown in an analysis of the relationship between the AO and the outbreak paths of cold waves,the anomalously strong AO years are accompanied with the transportation of anomalous low- level cold air masses while the anomalously weak AO years are not. In the former case,one route of cold air mass starts off from Mongolia and then diverts to Japan before traveling from the south of Japan to southern China,and the other route sets off from Siberia to pass Qinghai before diverting to Guangxi and then southern China.

关 键 词：气候学 北极涛动 寒潮 冷气团输送 华南地区 

分 类 号：P46[天文地球—大气科学及气象学]