A “La Niña-like” state occurring in the second year after large tropical volcanic eruptions during the past 1500 years

作     者：Sun, Weiyi Liu, Jian Wang, Bin Chen, Deliang Liu, Fei Wang, Zhiyuan Ning, Liang Chen, Mingcheng 

作者机构：Key Laboratory for Virtual Geographic Environment Ministry of Education Jiangsu Provincial State Key Laboratory Cultivation Base of Geographical Environment Evolution School of Geography Science Nanjing Normal University Nanjing 210023 China Jiangsu Provincial Key Laboratory for Numerical Simulation of Large Scale Complex Systems School of Mathematical Science Nanjing Normal University Nanjing 210023 China Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application Nanjing 210023 China Department of Atmospheric Sciences and Atmosphere-Ocean Research Center University of Hawaii at Manoa Honolulu 96825 HI United States Earth System Modeling Center and Climate Dynamics Research Center Nanjing University of Information Science and Technology Nanjing 210044 China Department of Earth Sciences University of Gothenburg Gothenburg 405 30 Sweden 

出 版 物：《Climate Dynamics》 (Clim. Dyn.)

年 卷 期：2019年第52卷第12期

页      面：7495-7509页

学科分类：07[理学] 070601[理学-气象学] 0706[理学-大气科学] 0816[工学-测绘科学与技术] 0825[工学-航空宇航科学与技术] 

基　　金：Earth Science and Technology, (1316) International Pacific Research Center Postgraduate Research and Practice Innovation Program of Jiangsu Province, (KYCX17_1061) National Natural Science Foundation of China, NSFC, (41371209, 41420104002, 41501210, 41671197) Natural Science Research of Jiangsu Higher Education Institutions of China, (14KJA170002) National Key Research and Development Program of China, NKRDPC, (2016YFA0600401) Priority Academic Program Development of Jiangsu Higher Education Institutions, PAPD, (10341, 164320H116) 

主　　题：CESM ENSO Impacts of volcanic eruption Volcano-induced La Niña WNPAC 

摘      要：Using an ensemble of nine El Niño/Southern Oscillation (ENSO) reconstructed proxies and volcano eruption proxies for the past 1500 years, this study shows that a significant La Niña state emerges in the second year (year (2) hereafter) after large tropical volcanic eruptions. The reasons for the development of La Niña are investigated using the Community Earth System Model (CESM). In the volcanic eruption experiment (Vol), a robust La Niña signal occurs in year (2), resembling the proxy records. The eastward positioning of the western North Pacific anomalous anticyclone (WNPAC) in Vol plays a critical role in the advanced decay of year (2) warming and the strong intensification of cooling in the equatorial eastern Pacific. The enhanced easterlies located on the southern edge of the WNPAC can stimulate consecutive oceanic upwelling Kelvin waves, shallowing the thermocline in the eastern Pacific, thereby resulting in a greater cooling rate by the enhanced thermocline feedback and cold zonal advection. Over the equatorial eastern Pacific, the reduced shortwave radiation contributes to the advanced decay of warming, while the upward latent heat flux augments the strong intensification of the cooling. Essentially, the eastward positioning of the WNPAC is a result of the volcanic forcing. The volcanic effect cools the maritime continent more than its adjacent oceans, thus pushing convective anomalies eastward during year (1). This induces vertical thermal advection and upward surface latent heat flux, thereby suppressing the development of warm Sea Surface Temperature over the central-western Pacific and causing the eastward positioning of the WNPAC in Vol. © 2018, The Author(s).