Causes of Winter Persistent Extreme Cold Events in Northeastern China  

作　　者：Ming YANG Qingjiu GAO Tim LI 

机构地区：[1]State Key Laboratory of Climate System Prediction and Risk Management/Key Laboratory of Meteorological Disaster,Ministry of Education/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science and Technology,Nanjing 210044,China [2]Department of Atmospheric Sciences,University of Hawaii at Manoa,Honolulu,HI 96822,USA

出　　处：《Advances in Atmospheric Sciences》2025年第4期780-793,共14页大气科学进展(英文版)

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.42088101 and 42075032).

摘　　要：Persistent(5-day or longer)extreme cold events(ECEs)over northeastern China during the boreal winter of 1979–2020 are investigated using daily minimum temperature(Tmin)from the China Meteorological Data Network.The extreme cooling area and intensity indices associated with the ECEs exhibit a dominant 10–40-day periodicity,indicating a close link with atmospheric intraseasonal oscillations(ISOs).The ECEs are categorized into W-and N-type.In the former,the low-frequency cooling associated with the ISO first penetrates into the western boundary of the northeastern China domain and later occupies the entire domain at its peak phase.The upper-tropospheric circulation associated with this type is characterized by a northwest–southeast-oriented Rossby wave train,expanding from the Ural Mountains to the western Pacific Ocean.In the latter,the cooling invades the northern boundary first and then penetrates into the entire domain.The upper tropospheric precursory signal associated with this type is a zonally oriented negative geopotential height anomaly,which slowly moves southward.A downward-propagating signal is observed in the stratospheric potential vorticity field prior to the peak cooling,implying a possible stratospheric impact.In addition to the W-and N-types,ECEs can also occur in a localized region near either at the northern or southern boundary of the domain.

关 键 词：extreme cold events low-frequency ISO mode Rossby wave train composite analysis downward propagation potential vorticity 

分 类 号：P423[天文地球—大气科学及气象学]