Pan-Atlantic decadal climate oscillation linked to ocean circulation

• Published in: Communications Earth & Environment
• Main Authors: Hyacinth C. Nnamchi, Riccardo Farneti, Noel S. Keenlyside, Fred Kucharski, Mojib Latif, Annika Reintges, Thomas Martin
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Portfolio 2023
• Subjects: Geology; QE1-996.5; Environmental sciences; GE1-350; North Atlantic; North Atlantic oscillation
• Online Access: https://doi.org/10.1038/s43247-023-00781-x; https://doaj.org/article/41c4ddf3f8304773a23c452e577bb484

Abstract Atlantic climate displays an oscillatory mode at a period of 10–15 years described as pan-Atlantic decadal oscillation. Prevailing theories on the mode are based on thermodynamic air-sea interactions and the role of ocean circulation remains uncertain. Here we uncover ocean circulation variability associated with the pan-Atlantic decadal oscillation using observational datasets from 1900–2009. Specifically, a sea level-derived index of ocean circulation also exhibits 10-15 year periodicity and leads the surface climate oscillation. The underlying ocean circulation links the extratropical and tropical Atlantic, where the maximum variance in surface-ocean temperature feeds back on the North Atlantic Oscillation (the leading mode of atmospheric variability over the North Atlantic region). Our findings imply that, rather than a passive role postulated by the thermodynamic paradigm, ocean circulation across the Atlantic plays an active role for the pan-Atlantic decadal climate oscillation.