Wind Spatial Structure Triggers ENSO’s Oceanic Warm Water Volume Changes

Abstract This study demonstrates that the generalization strong anomalous equatorial Pacific westerly (easterly) winds during El Niño (La Niña) events display adjusted warm water volume (WWV) discharges (recharges) is often incorrect. Using ocean model simulations, we categorize oceanic responses to into two categories: (i) transitioning (consistent with above generalization) and (ii) neutral (with negligible WWV recharge discharge). During 1980–2016 period only 47% of are followed by responses, while remaining responses. Moreover, 55% (only 30%) strongest lead pre-2000 (post-2000) in agreement previously reported post-2000 decline time Niño–Southern Oscillation (ENSO) events. The prominent response shown be largely excited wind stress forcing a weaker curl (on average consistent higher ratio off-equatorial events) Rossby wave projection than response. We also identify ENSO phase asymmetry where (i.e., roughly 1.6 times more likely strongly discharge easterly La Niña WWV. may added list mechanisms proposed explain why have stronger tendency vice versa.