caa a22 4500 605473188 CHVBK 20210128100341.0 cr unu---uuuuu 210128e20150201xx s 000 0 eng 10.1007/s00382-014-2145-1 doi (NATIONALLICENCE)springer-10.1007/s00382-014-2145-1 Effects of extratropical warming on ENSO amplitudes in an ensemble of a coupled GCM [Elektronische Daten] [Kuniko Yamazaki, Masahiro Watanabe] The El Niño-Southern Oscillation (ENSO) amplitudes in an ensemble of twentieth-century coupled general circulation model experiments performed for the Coupled Model Intercomparison Project phase 5 were found to have a systematic relationship with the time-averaged Southern Ocean sea surface temperature (SST). That is, the ENSO amplitudes were greater in the ensemble members with warmer Southern Ocean SST. Here we propose a mechanism that explains how the anomalous extratropical warming remotely affects the ENSO strength. First, the reduction in the meridional temperature gradient over the Southern Hemisphere gives rise to an anomalous northward heat transport by transient eddies across the extratropics into the tropics. This induces an anomalous Hadley cell that leads to a northward heat transport within the tropics in its upper branch and a southward moisture transport in the lower branch. The latter reduces maximum precipitation in the intertropical convergence zone in the equatorial Pacific Ocean and increases precipitation in the adjacent region to the south. Since the amount of precipitation over the eastern equatorial Pacific dictates the strength of ENSO through the shift in the zonal wind stress response to El Niño/La Niña, we conclude that there is an energy transport pathway through which the ENSO strength can be remotely modulated by the anomalous heating in the extratropics. The Author(s), 2014 El Niño-southern oscillation nationallicence ITCZ nationallicence Atmospheric energy transport nationallicence Yamazaki Kuniko Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, 277-8564, Chiba, Japan aut Watanabe Masahiro Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, 277-8564, Chiba, Japan aut Climate Dynamics Springer Berlin Heidelberg 44/3-4(2015-02-01), 679-693 0930-7575 44:3-4<679 2015 44 382 https://doi.org/10.1007/s00382-014-2145-1 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00382-014-2145-1 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Yamazaki Kuniko Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, 277-8564, Chiba, Japan aut NATIONALLICENCE 700 1- Watanabe Masahiro Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, 277-8564, Chiba, Japan aut NATIONALLICENCE 773 0- Climate Dynamics Springer Berlin Heidelberg 44/3-4(2015-02-01), 679-693 0930-7575 44:3-4<679 2015 44 382