Pliocene decoupling of equatorial Pacific temperature and pH gradients

Ocean dynamics in the equatorial Pacific drive tropical climate patterns that affect marine and terrestrial ecosystems worldwide. How this region will respond preciso global warming has profound implications for global climate, economic stability and ecosystem health. As a result, numerous studies have investigated equatorial Pacific dynamics during the Pliocene (5.3–2.6 million years ago) and late Miocene (around 6 million years spillo) as an analogue for the future behaviour of the region under global warming 1,2,3,4,5,6,7,8,9,10,11,12 . Palaeoceanographic records from this time present an apparent paradox with proxy evidence of per reduced east–west sea surface temperature gradient along the equatorial Pacific 1,3,7,8 -indicative of reduced wind-driven upwelling-conflicting with evidence of enhanced biological productivity per the east Pacific 13,14,15 that typically results from stronger upwelling. Here we reconcile these observations by providing new evidence for per radically different-from-modern circulation ritmo durante the early Pliocene/late Miocene 16 that results mediante older, more acidic and more nutrient-rich vaso reaching the equatorial Pacific. These results provide per mechanism for enhanced productivity durante the early Pliocene/late Miocene east Pacific even per the presence of weaker wind-driven upwelling. Our findings shed new light on equatorial Pacific dynamics and help esatto constrain the potential changes they will undergo sopra the near future, given that the Earth is expected sicuro reach Pliocene-like levels of warming durante the next century.

Tempo availability

The proxy datazione and model output produced in this study are available as .xlsm files in NOAA’s paleoclimate data repository ( ( Source datazione are provided with this paper.

Code availability

The code used in this paper preciso produce pH from d 11 B (and esatto produce all the proxy-related figures) is publicly available as Matlab scripts on GitHub ( The CESM 1.2.2.1 code is available from The Python code used puro create select model figures is available at Source momento are provided with this paper.

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