江西地区冬半年极端低温事件主模态及环流特征  

Dominant Mode and Associated Circulation Anomalies of Extreme Low Temperature Events in Jiangxi During Boreal Winter

作　　者：马锋敏[1] 刘冬梅 Ma Fengmin;Liu Dongmei(Jiangxi Provincial Climate Center,Nanchang 330096,China;Jiangxi Provincial Meteorological Data Center,Nanchang 330096,China)

机构地区：[1]江西省气候中心,江西南昌330096 [2]江西省气象数据中心,江西南昌330096

出　　处：《气象与减灾研究》2023年第1期1-8,共8页Meteorology and Disaster Reduction Research

基　　金：江西省气象局重点项目“江西省霾短期气候预测技术及大气污染输送研究”。

摘　　要：基于1961—2022年江西日最低气温观测资料和NCEP/NCAR再分析资料,首先极端低温阈值,分析极端低温事件发生频次的分布特征;再利用经验正交函数(EOF)获得极端低温事件发生频次的主模态,分析相应的关键环流系统特征。结果表明:江西省大部分地区冬半年极端低温阈值在0℃以下,南北分布差异较明显。极端低温事件发生频次在空间上具有很好的一致性,在1985年前后由偏多转为偏少的年代际振荡。极端低温发生频次主模态的变化受冬季风系统关键成员的影响显著,东亚冬季风偏强、西伯利亚高压偏强、东亚大槽加深、副热带西风急流偏强都利于江西地区出现极端低温事件。The dominant mode of extreme low temperature events in Jiangxi during boreal winter and its associated circulation anomalies were investigated using daily minimum temperature data and NCEP/NCAR reanalysis dataset from1961 to 2022.The main mode in the frequency of extreme low temperature events and the corresponding key circulation system characteristics were obtained by EOF.The results showed that 95.1% of the stations in Jiangxi presented extreme low temperature threshold below 0 ℃ in boreal winter,and the distribution difference between north and south was obvious.The frequency of extreme low temperature events exhibited a good relationship with the spatial distribution,and an obvious inter-decadal oscillation from more to less occurred around 1985.There was a significant positive correlation between the frequency of extreme low temperature and the East Asian winter monsoon index.The stronger East Asian winter monsoon,Siberian high,subtropical westerly jet and the deeper East Asian trough were conducive to the occurrence of extreme low temperature events.

关 键 词：极端低温 阈值 频次 主模态 东亚冬季风 

分 类 号：P462.4[天文地球—大气科学及气象学]