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Western Pacific Oceanic Heat Content: A Better Predictor of La Niña Than of El Niño
Author(s) -
Planton Yann,
Vialard Jérôme,
Guilyardi Eric,
Lengaigne Matthieu,
Izumo Takeshi
Publication year - 2018
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 - 10.1029/2018gl079341
Subject(s) - el niño southern oscillation , boreal , climatology , amplitude , coupled model intercomparison project , environmental science , wind stress , oceanography , pacific decadal oscillation , phase (matter) , atmospheric sciences , geology , physics , climate model , climate change , paleontology , quantum mechanics
The western equatorial Pacific oceanic heat content (warm water volume in the west or WWV w ) is the best El Niño–Southern Oscillation (ENSO) predictor beyond 1‐year lead. Using observations and selected Coupled Model Intercomparison Project Phase 5 simulations, we show that a discharged WWV w in boreal fall is a better predictor of La Niña than a recharged WWV w for El Niño 13 months later, both in terms of occurrence and amplitude. These results are robust when considering the heat content across the entire equatorial Pacific (WWV) at shorter lead times, including all Coupled Model Intercomparison Project Phase 5 models or excluding Niño‐Niña and Niña‐Niño phase transitions. Suggested mechanisms for this asymmetry include (1) the negatively skewed WWV w distribution with stronger discharges related to stronger wind stress anomalies during El Niño and (2) the stronger positive Bjerknes feedback loop during El Niño. The possible role of stronger subseasonal wind variations during El Niño is also discussed.