山东春季极端低温与前冬北大西洋海温的关系  

Relationship between extremely low temperature in spring in Shandong Province and North Atlantic SST in preceding winter

作　　者：徐玮平 孟祥新 顾伟宗[1,3] 伯忠凯 XU Weiping;MENG Xiangxin;GU Weizong;BO Zhongkai(Key Laboratory for Meteorological Disaster Prevention and Mitigation of Shandong Province,Jinan 250031,China;Shandong Provincial Climate Center,Jinan 250031,China;Ensuring Center of Atmospheric Sounding Technology of Shandong Provincial Meteorological Bureau,Jinan 250031,China)

机构地区：[1]山东省气象防灾减灾重点实验室,山东济南250031 [2]山东省气候中心,山东济南250031 [3]山东省气象局大气探测技术保障中心,山东济南250031

出　　处：《干旱气象》2022年第2期202-211,共10页Journal of Arid Meteorology

基　　金：山东省气象局科研项目(2020SDQN03,2016sdqxz02)资助。

摘　　要：基于1961—2018年山东122个国家级气象站逐日气温资料,计算3个极端低温指数,发现利用日最低气温24 h降温幅度定义的极端低温事件发生频率可以更好地反映山东春季极端低温特征。在此基础上利用ERA-Interim逐月再分析资料和Hadley海温数据分析山东春季极端低温事件发生频率时空分布特征及大气环流异常特征。结果表明:(1)山东春季极端低温事件发生频率具有多时间尺度变化特征;(2)山东春季典型极端低温年500 hPa位势高度距平场中高纬呈现出明显的波列结构;(3)格陵兰岛以南的北大西洋是垂直波作用通量传输的关键区,在该关键区低层能量向上传输,传输到高层的能量向外频散,有利于山东地区春季极端低温的维持和加强;(4)前冬北大西洋海温“三极子”模态与山东春季极端低温事件发生频率显著正相关,海温“三极子”模态异常激发出欧亚波列,导致贝加尔湖地区500 hPa高空槽加深加强,受槽后冷空气影响,山东春季极端低温事件频发。Based on daily temperature data from 122 national meteorological stations in Shandong Province from 1961 to 2018,three extreme low temperature indices were calculated,and it was found that the occurrence frequency of extremely low temperature events defined by the scale of drop in daily minimum temperature in 24 hours could better reflect the characteristics of extremely low temperature in spring in Shandong.And on this basis,ERA-Interim monthly reanalysis data and Hadley sea surface temperature data were used to analyze the spatial and temporal distribution characteristics of occurrence frequency of extremely low temperature events in spring in Shandong and the anomalous characteristics of atmospheric circulation.The results are as follows:(1) The occurrence frequency of extremely low temperature events had multi-time scale variation characteristics in spring in Shandong.(2) The obvious wave train structure on 500 hPa geopotential height field was existed in mid-high latitudes in the typical extreme low temperature years in spring in Shandong.(3) The North Atlantic Ocean to the south of Greenland was a key area for vertical wave flux transmission.In this key area,the energy in the lower layer transmitted upward,and dispersed outward in the upper layer,which was beneficial to the maintenance and enhancement of the extremely low temperature in spring in Shandong.(4) The triple pole mode of sea surface temperature in the North Atlantic in the preceding winter had a significant positive correlation with the occurrence frequency of extremely low temperature events in spring in Shandong.The triple pole mode of sea surface temperature excited the Eurasian wave,which led to the deepening and strengthening of 500 hPa trough over the Lake Baikal area.Due to the influence of cold air behind the trough,the extremely low temperature events occurred frequently in spring in Shandong.

关 键 词：极端低温事件 大气环流 波作用通量 海温模态 

分 类 号：P467[天文地球—大气科学及气象学]