Dynamical influence of the Madden-Julian oscillation on the Northern Hemisphere mesosphere during the boreal winter  

作　　者：Cong SUN Chengyun YANG Tao LI 

机构地区：[1]CAS Key Laboratory of Geospace Environment,School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,China [2]Mengcheng National Geophysical Observatory,School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,China [3]CAS Center for Excellence in Comparative Planetology,University of Science and Technology of China,Hefei 230026,China

出　　处：《Science China Earth Sciences》2021年第8期1254-1266,共13页中国科学（地球科学英文版）

基　　金：supported by the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB 41000000);the National Natural Science Foundation of China(Grant Nos.41874180,41974175,41831071,and 41874181);the Open Research Project of Large Research Infrastructures of CAS—“Study on the interaction between low/mid-latitude atmosphere and ionosphere based on the Chinese Meridian Project”.

摘　　要：This study first investigates the effect of the Madden-Julian Oscillation(MJO)on the Northern Hemisphere(NH)mesosphere.Both observations and simulations suggest significant cooling in the NH polar mesosphere approximately 35 days after MJO phase 4(P4),which lags the MJO-induced perturbation in the upper stratosphere by 10 days.The enhanced planetary waves(PWs)propagate upward and result in wavenumber-1 pattern temperature anomalies in the mesosphere lagging MJO P4 by 25 days.The anomalous PWs also lead to the weaker eastward zonal wind in the upper stratosphere and lower mesosphere lagging MJO P4 by 30 days.Simultaneously,the weaker westerlies result in weaker climatological westward gravity waves(GWs)in the mesosphere due to critical-level filtering.The mesosphere meridional circulation is suppressed due to both anomalous PWs and GWs,and this suppression causes polar mesospheric cooling lagging MJO P4 by 35 days.

关 键 词：MJO Mesospheric polar cooling Planetary waves Gravity waves Vertical dynamical coupling 

分 类 号：P433[天文地球—大气科学及气象学]