1970-2019年中国大陆地区寒潮年代际变化及大气环流成因  

Study on interdecadal variations of cold wave and genesis of atmospheric circulation in the Chinese Mainland from 1970 to 2019

作　　者：朱姜韬 路瑶[1] 李艳[1] ZHU Jiang-tao;LU Yao;LI Yan(College of Atmospheric Sciences,Lanzhou University,Lanzhou 730000,China)

机构地区：[1]兰州大学大气科学学院,兰州730000

出　　处：《兰州大学学报（自然科学版）》2022年第3期337-346,355,共11页Journal of Lanzhou University(Natural Sciences)

基　　金：国家自然科学基金面上项目(41775051)。

摘　　要：利用中国中央气象台的寒潮过程统计资料及NCEP/NCAR再分析资料,根据1970-2019年寒潮的气候特征,探究春季寒潮的年代际变化特征及其大气环流成因.结果表明,1970-2019年寒潮事件发生频次整体呈下降趋势,但自1990s开始出现转折,寒潮频次开始呈波动上升趋势.1990s后春季寒潮事件持续时间延长近0.8 d,寒潮期间主要降温区域偏西、偏南.对比1990s前后春季寒潮期间的大气环流形势,1990s后春季寒潮事件过程中,东亚地区极涡的位置偏西,500 hPa上乌拉尔山高压脊位置偏东、偏北且消失时间偏晚4 d,东亚大槽偏强且位置偏东,西伯利亚冷高压偏强、偏西.利用定量化指数研究发现,1990s后东亚大槽减弱消失时间延后2 d,地面西伯利亚冷高压衰亡时间延后2 d,且中心位置经度偏西约7°.大气环流的高低空异常配置可以解释1990 s前后中国大陆春季寒潮强度变强、持续期变长和影响范围偏西、偏南的年代际变化.Based on the statistical data of cold wave process in the Chinese Mainland provided by the Central Meteorological Observatory of China and NCEP/NCAR reanalysis data,this study analyzed the climate characteristics of cold wave from 1970 to 2019,and further explored the interdecadal variation characteristics of cold wave in spring and its atmospheric circulation causes.The results showed that the frequency of cold wave events from 1970 to 2019 displayed a downward trend as a whole,but since1990’s,the frequency of cold wave events began to fluctuate and increase.Compared with that before1990’s,the duration of cold wave events in spring prolonged by nearly 0.8 days,and the main cooling areas during the cold wave period were more west and south after 1990’s.Looking at the atmospheric circulation situation during the cold wave around 1990’s,it was found that,compared with the cold wave events before 1990’s,and during the spring cold wave events after 1990’s,the polar vortex in East Asia was located to the west,the high ridge of the Ural Mountains at 500 hPa was located to the east and disappeared 4 days later,the East Asian trough was stronger and located to the east,and the Siberian cold high was stronger and westward.Using the quantitative index,it was found that after 1990’s,the weakening and disappearing time of the East Asian trough was delayed by 2 days,and the decline time of the Siberian cold high on the ground was delayed by 2 days,and the center was about 7 longitudes to the west.The anomalous distribution of the atmospheric circulation at the high and low altitude could explain the interdecadal variations of spring cold wave in the Chinese Mainland around 1990’s with a stronger intensity,longer duration and south-west influence range.

关 键 词：寒潮 年代际变化 极涡 东亚大槽 乌拉尔山高压脊 西伯利亚冷高压 

分 类 号：P423.3[天文地球—大气科学及气象学]