ITCZ shift and extratropical teleconnections drive ENSO response to volcanic eruptions

Pausata, Francesco S.R.; Zanchettin, Davide; Karamperidou, Christina; Caballero, Rodrigo et Battisti, Davide S. (2020). « ITCZ shift and extratropical teleconnections drive ENSO response to volcanic eruptions ». Science Advances(6).

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Résumé

The mechanisms through which volcanic eruptions affect the El Niño–Southern Oscillation (ENSO) state are still controversial. Previous studies have invoked direct radiative forcing, an ocean dynamical thermostat (ODT) mechanism, and shifts of the Intertropical Convergence Zone (ITCZ), among others, to explain the ENSO response to tropical eruptions. Here, these mechanisms are tested using ensemble simulations with an Earth system model in which volcanic aerosols from a Tambora-like eruption are confined either in the Northern or the Southern Hemisphere. We show that the primary drivers of the ENSO response are the shifts of the ITCZ together with extratropical circulation changes, which affect the tropics; the ODT mechanism does not operate in our simulations. Our study highlights the importance of initial conditions in the ENSO response to tropical volcanic eruptions and provides explanations for the predominance of posteruption El Niño events and for the occasional posteruption La Niña in observations and reconstructions.

Type: Article de revue scientifique
Mots-clés ou Sujets: Volcanoes and Climate
Unité d'appartenance: Centres institutionnels > Centre de recherche en géochimie et géodynamique (GEOTOP)
Centres institutionnels > Centre pour l'étude et la simulation du climat à l'échelle régionale (ESCER)
Déposé par: Francesco S. R. Pausata
Date de dépôt: 19 juin 2020 13:47
Dernière modification: 19 juin 2020 13:47
Adresse URL : http://archipel.uqam.ca/id/eprint/13371

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