caa a22 4500 605473676 CHVBK 20210128100344.0 cr unu---uuuuu 210128e20150401xx s 000 0 eng 10.1007/s00382-014-2303-5 doi (NATIONALLICENCE)springer-10.1007/s00382-014-2303-5 The impact of South Pacific extratropical forcing on ENSO and comparisons with the North Pacific [Elektronische Daten] [Ruiqiang Ding, Jianping Li, Yu-heng Tseng] Previous studies suggest that North Pacific extratropical atmospheric variability influences ENSO via the seasonal footprinting mechanism (SFM). This study confirms that quadrapole sea surface temperature (SST) variability in the extratropical South Pacific triggered by mid-latitude South Pacific atmospheric variability may also have an additional influence on ENSO. The response of the evolution of the ENSO-related zonal wind and SST anomalies in the tropics to the South Pacific extratropical forcing is consistent with the SFM hypothesis. That is, the Pacific-South American (PSA) pattern of the South Pacific extratropical sea level pressure (SLP) anomalies imparts an SST footprint (i.e., a quadrapole SST pattern) onto the ocean during austral summer. This SST footprint subsequently forces the zonal wind anomalies along the equator in the following austral winter that ultimately result in ENSO events during the following austral summer via ocean-atmosphere coupling in the tropics. The present study demonstrates that the influences of extratropical atmospheric variability in the South Pacific and North Pacific on ENSO are different and relatively independent. It is possible that they may, together or separately, influence the occurrence of ENSO events, and the importance of the South Pacific forcing in initiating ENSO events is comparable with that of the North Pacific forcing. An empirical model was established to predict the Niño3.4 index based on the combined South Pacific and North Pacific signals, and results show that it can be used to produce skillful forecasts of the Niño3.4 index with a leading time of up to 1year. Springer-Verlag Berlin Heidelberg, 2014 The Pacific-South American (PSA) pattern nationallicence ENSO nationallicence Quadrapole SST pattern nationallicence Ding Ruiqiang State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics, Chinese Academy of Sciences, P.O. Box 9804, 100029, Beijing, China aut Li Jianping State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics, Chinese Academy of Sciences, P.O. Box 9804, 100029, Beijing, China aut Tseng Yu-heng Climate and Global Dynamics Division, NCAR, Boulder, CO, USA aut Climate Dynamics Springer Berlin Heidelberg 44/7-8(2015-04-01), 2017-2034 0930-7575 44:7-8<2017 2015 44 382 https://doi.org/10.1007/s00382-014-2303-5 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/s00382-014-2303-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ding Ruiqiang State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics, Chinese Academy of Sciences, P.O. Box 9804, 100029, Beijing, China aut NATIONALLICENCE 700 1- Li Jianping State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics, Chinese Academy of Sciences, P.O. Box 9804, 100029, Beijing, China aut NATIONALLICENCE 700 1- Tseng Yu-heng Climate and Global Dynamics Division, NCAR, Boulder, CO, USA aut NATIONALLICENCE 773 0- Climate Dynamics Springer Berlin Heidelberg 44/7-8(2015-04-01), 2017-2034 0930-7575 44:7-8<2017 2015 44 382