Multi-year La Niña frequency tied to southward tropical Pacific wind shift

Multi-year La Niña events cause prolonged climate disruptions worldwide, but a systematic understanding of the underlying mechanisms is not yet established. Here we show using observations and models from the sixth phase of Coupled Model Intercomparison Project that a greater frequency of consecutiv...

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Bibliographic Details
Published inNPJ climate and atmospheric science Vol. 7; no. 1; pp. 226 - 8
Main Authors Wang, Guojian, Santoso, Agus
Format Journal Article
LanguageEnglish
Published London Nature Publishing Group UK 30.09.2024
Nature Publishing Group
Nature Portfolio
Subjects
704/106/35/823
704/172/4081
Atmospheric Protection/Air Quality Control/Air Pollution
Atmospheric Sciences
Climate Change/Climate Change Impacts
Climate models
Climate prediction
Climatology
Discharge
Earth and Environmental Science
Earth Sciences
El Nino
Enthalpy
Heat
La Nina
Nonlinear systems
Ocean models
Southern Oscillation
Thermocline
Wind
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Summary:Multi-year La Niña events cause prolonged climate disruptions worldwide, but a systematic understanding of the underlying mechanisms is not yet established. Here we show using observations and models from the sixth phase of Coupled Model Intercomparison Project that a greater frequency of consecutive La Niña events is tied to the upper equatorial Pacific Ocean when it favors more rapid heat discharge. The propensity for heat discharge is underscored by negative skewness in upper-ocean heat content, underpinned by southward tropical Pacific wind shift during austral summer. Models with stronger westerly anomalies south of the equator simulate steeper east-to-west upward tilt of the thermocline that is favorable for a greater discharge rate. This highlights the crucial role of the southward wind shift in the nonlinear system of the El Niño-Southern Oscillation. The large inter-model spread in multi-year La Niña processes underscores the need in constraining models for reliable climate prediction and projection.
ISSN:2397-3722
2397-3722
DOI:10.1038/s41612-024-00772-5