Pliocene decoupling of equatorial Pacific temperature and pH gradients
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Pliocene decoupling of equatorial Pacific temperature and pH gradients
Pliocene decoupling of equatorial Pacific temperature and pH gradients

Ocean dynamics mediante 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 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 a 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 a radically different-from-modern circulation governo con the early Pliocene/late Miocene 16 that results mediante older, more acidic and more nutrient-rich water reaching the equatorial Pacific. These results provide per mechanism for enhanced productivity in 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 puro constrain the potential changes they will undergo durante the near future, given that the Earth is expected sicuro reach Pliocene-like levels of warming per the next century.

Datazione availability

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

Code availability

The code used con 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 puro create select model figures is available at Source giorno are provided with this paper.

References

Wara, M. W., Ravelo, Verso. C. & Delaney, M. L. Permanent El Nino-like conditions during the Pliocene warm period. Science 309, 758–761 (2005).

Zhang, Y. G., Pagani, M. & Liu, Z. A 12-million-year temperature history of the tropical Pacific Ocean. Science 344, 84–88 (2014).

Fedorov, A. V., Burls, N. J., Lawrence, K. T. & Peterson, L incontri willow. C. Tightly linked zonal and meridional sea surface temperature gradients over the past five million years. Nat. Geosci. 8, 975–980 (2015).

Ford, H. L., Ravelo, Per. C., Dekens, P. S., LaRiviere, J. P. & Wara, M. W. The evolution of the equatorial thermocline and the early Pliocene El Babbo mean state. Geophys. Res. Lett. 42, 4878–4887 (2015).

Tierney, J. Ed., Haywood, Verso. M., Feng, R., Bhattacharya, Tau. & Otto?Bliesner, B. L. Pliocene warmth consistent with greenhouse gas forcing. Geophys. Res. Lett. 46, 9136–9144 (2019).

Lawrence, K. Tau., Liu, Z. & Herbert, Tau. D. Evolution of the eastern tropical Pacific through Plio-Pleistocene glaciation. Science 312, 79–83 (2006).

Dekens, P. S., Ravelo, Verso. C. & McCarthy, M. D. Warm upwelling regions per the Pliocene warm period. Paleoceanography 22, PA3211 (2007).

Ford, H. L., Ravelo, Verso. C. & Hovan, S. A deep Eastern Equatorial Pacific thermocline during the early Pliocene warm period. Earth Planet. Sci. Lett. 355, 152–161 (2012).

O'Brien, C. L. et al. High sea surface temperatures per tropical warm pools during the Pliocene. Nat. Geosci. 7, 606–611 (2014).

Ravelo, Verso. C., Lawrence, K. Tau., Fedorov, A. & Ford, H. L. Comment on “Verso 12-million-year temperature history of the tropical Pacific Ocean”. Science 346, 1467 (2014).

Lyle, M. & Baldauf, J. Biogenic sediment regimes mediante the Neogene equatorial Pacific, IODP Site U1338: burial, production, and diatom community. Palaeogeogr. Palaeoclimatol. Palaeoecol. 433, 106–128 (2015).

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