东亚大槽和西伯利亚高压的季节内变率对冬季东亚气温的影响  

Impacts of intra-seasonal variability of the East Asian trough and the Siberian high on East Asian temperatures in the northern winter

作　　者：李天明[1,2] 丁柳丹 LI Tim;DING Liudan(Key Laboratory of Meteorological Disaster,Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disaster(CIC-FEMD),Nanjing University of Information Science and Technology,Nanjing 210044,China;Department of Atmospheric Sciences,University of Hawaii at Manoa,Honolulu 96822,USA)

机构地区：[1]南京信息工程大学气象灾害教育部重点实验室/气候与环境变化国际联合实验室/气象灾害预报预警与评估协同创新中心,江苏南京210044 [2]夏威夷大学马诺阿分校大气科学系,夏威夷檀香山96822

出　　处：《大气科学学报》2024年第2期184-200,共17页Transactions of Atmospheric Sciences

基　　金：国家自然科学基金资助项目(42088101)。

摘　　要：基于气候态定义了西伯利亚高压指数(SH index)、东亚大槽指数(ET index)和高低压系统间的东亚经向风指数(V index),使用回归分析探究西伯利亚高压和东亚大槽在季节内尺度上对东亚地区冬季温度的影响机理,构建线性模型对冬季华南地区季节内尺度温度进行延伸期预报。结果表明:西伯利亚高压和东亚大槽系统变化中最显著的是季节内尺度信号;季节内尺度SH index和ET index对V index的贡献分别为82.6%和42.2%;3个指数的回归模态在对流层中层对应西北-东南向低频罗斯贝波列缓慢东南传播,低层水汽、近地面层环流、降水及2 m温度场配置良好,当西伯利亚高压深厚或东亚大槽发展时,经向风关键区北风强盛,有利于冬季高纬度地区干冷空气向东亚输送;V index对华南地区冬季季节内尺度2 m气温的有效预报时效达25 d。Both the Siberian high and the East Asian trough play crucial roles in the East Asian winter climate system.Changes in the strength and position of the Siberian high can lead to the movement of cold or warm air masses over the East Asian continent,while variations in the East Asian trough can influence circulation patterns in the western Pacific.These combined effects can alter temperature and precipitation distributions in East Asia during the winter,significantly impacting the winter climate.This study defines the Siberian High(SH)index,the East Asian Trough(ET)index,and a Meridional Wind(V index)index between the high and low-pressure systems based on climatological characteristics.The relationships between these indices are explored using power spectrum analysis and linear regressions.The study investigates the significant periods of variability and the impact mechanisms of the Siberian high and East Asian trough on winter temperatures in East Asia.Additionally,a simple linear regression model is constructed using a non-filtering method and cross-validation for extended-range forecasts of intra-seasonal temperatures in southern China during the winter.The main conclusions are as follows:The most significant periods of the SH and ET indices occur on intra-seasonal timescales,accounting for 60%of the total standard deviation.Power spectrum analysis results show that the energy peaks of the SH and ET indices are concentrated in the 10-50-day period,while the V index is more concentrated in the 10-40-day period.On the intra-seasonal timescales,the correlation coefficients between the SH/ET indices and the V index are 0.69 and-0.73,respectively(through a 99%confidence test).The reconstructed meridional wind fields related to the SH/ET indices are used to calculate the ratio of the standard deviation compared to the actual meridional wind field.Quantitative results show that the contributions of the intra-seasonal SH and ET indices to the V index are 82.6%and 42.2%,respectively.Lead-lag regression analysis for the

关 键 词：西伯利亚高压 东亚大槽 季节内尺度变率 冬季东亚气温 延伸期预报 

分 类 号：P423[天文地球—大气科学及气象学]