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Role of Stratospheric Sudden Warmings on the response to Central Pacific El Niño
Author(s) -
Iza Maddalen,
Calvo Natalia
Publication year - 2015
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2014gl062935
Subject(s) - northern hemisphere , polar , climatology , pacific ocean , southern hemisphere , atmospheric sciences , environmental science , geology , oceanography , physics , astronomy
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.