Ocean dynamics per the equatorial Pacific drive tropical climate patterns that affect marine and terrestrial ecosystems worldwide. How this region will respond esatto global warming has profound implications for global climate, economic stability and ecosystem health. As verso 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 ago) 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 con the east Pacific 13,14,15 that typically results from stronger upwelling. Here we reconcile these observations by providing new evidence for verso radically different-from-modern circulation consuetudine in the early Pliocene/late Miocene 16 that results in older, more acidic and more nutrient-rich tazza reaching the equatorial Pacific. These results provide per mechanism for enhanced productivity con the early Pliocene/late Miocene east Pacific even in the presence of weaker wind-driven upwelling. Our findings shed new light on equatorial Pacific dynamics and help onesto constrain the potential changes they will undergo con the near future, given that the Earth is expected to reach Pliocene-like levels of warming con the next century.
Momento availability
The proxy scadenza and model output produced durante this study are available as .xlsm files per NOAA’s paleoclimate tempo repository ( ( Source tempo are provided with this paper.
Code availability
The code used in this paper esatto produce pH from d 11 B (and onesto 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 sicuro create select model figures is available at Source data are provided with this paper.
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