RT Journal Article T1 Role of Stratospheric Sudden Warmings on the response to Central Pacific El Niño A1 Iza San Juan, Maddalen A1 Calvo Fernández, Natalia AB The Northern Hemisphere (NH) polar stratospheric response to Central Pacific El Niño (CP-El Niño) events remains unclear. Contradictory results have been reported depending on the definition and events considered. We show that this is due to the prominent role of Stratospheric Sudden Warmings (SSWs), whose signal dominates the NH winter polar stratospheric response to CP-El Niño. In fact, the CP-El Niño signal is robust when the events are classified according to the occurrence of SSWs and displays opposite response in winters with and without SSWs. In the absence of SSWs, polar stratospheric responses to Central Pacific and Eastern Pacific El Niño are clearly distinguishable in early winter, in relation to differences in the Pacific-North American pattern. Our results demonstrate that the occurrence of SSWs needs to be taken into account when studying the stratospheric response to CP-El Niño and explain why different responses to CP-El Niño have been reported previously. PB American Geophysical Union SN 0094-8276 YR 2015 FD 2015-04-16 LK https://hdl.handle.net/20.500.14352/24039 UL https://hdl.handle.net/20.500.14352/24039 LA eng NO © 2015. The Authors. We acknowledge the ECMWF for providing ERA-40 and ERA-Interim reanalysis data (http://apps.ecmwf.int/datasets/) and the NCEP/CPC for the Niño3 and Niño4 indices (http://www.cpc.ncep.noaa.gov/data/indices/). This work was supported by the Spanish Ministry of Economy and Competitiveness through the MATRES (CGL2012-34221) project and the European Project 603557-STRATOCLIM under program FP7-ENV.2013.6.1-2. The authors are grateful to R. R. García for his comments on the manuscript and to R. García Herrera and D. Barriopedro for their fruitful discussions. The constructive comments of two anonymous reviewers are gratefully acknowledged. NO Unión Europea. FP7 NO Ministerio de Economía y Competitividad (MINECO), España DS Docta Complutense RD 10 abr 2025