September 2025

September 2025 | Oceanography

23

Robinson, L.F., J.F. Adkins, L.D. Keigwin, J. Southon, D.P. Fernandez, S.L. Wang, and

D.S. Scheirer. 2005. Radiocarbon variability in the western North Atlantic during the

last deglaciation. Science 310:1,469–1,473, https://doi.org/10.1126/science.1114832.

Ruddiman, W.F. 1977. Late Quaternary deposition of ice-rafted sand in the subpolar

North Atlantic (lat 40° to 65°N). GSA Bulletin 88(12):1,813–1,827, https://doi.org/10.1130/

0016-7606(1977)88<1813:lqdois>2.0.co;2.

Sarmiento, J.L., and N. Gruber. 2006. Ocean Biogeochemical Dynamics. Princeton

University Press, Princeton, NJ.

Shackleton, N.J., M.A. Hall, and E. Vincent. 2000. Phase relationships between millen-

nial-​scale events 64,000–24,000 years ago. Paleoceanography 15(6):565–569,

https://doi.org/10.1029/2000pa000513.

Sima, A., A. Paul, and M. Schulz. 2004. The Younger Dryas—An intrinsic feature of late

Pleistocene climate change at millennial timescales. Earth and Planetary Science

Letters 222(3–4):741–750, https://doi.org/10.1016/j.epsl.2004.03.026.

Skinner, L.C., and N.J. Shackleton. 2004. Rapid transient changes in northeast

Atlantic deep water ventilation age across Termination I. Paleoceanography 19(2),

https://doi.org/​10.1029/2003pa000983.

Skinner, L.C., H. Elderfield, and M. Hall. 2007. Phasing of Millennial Climate Events and

Northeast Atlantic Deep-Water Temperature Change Since 50 Ka Bp. Pp. 197–208

in Ocean Circulation: Mechanisms and Impacts – Past and Future Changes of

Meridional Overturning, Volume 173. A. Schmittner, J. Chiang, and S. Hemming, eds,

Geophysical Monograph Series, American Geophysical Union, Washington, DC,

https://doi.org/10.1029/173GM14.

Snoll, B., R. Ivanovic, L. Gregoire, S. Sherriff-Tadano, L. Menviel, T. Obase,

A. Abe-Ouchi, N. Bouttes, C. He, F. He, and others. 2024. A multi-model assessment

of the early last deglaciation (PMIP4 LDv1): A meltwater perspective. Climate of the

Past 20(4):789–815, https://doi.org/10.5194/cp-20-789-2024.

Spall, M.A. 2004. Boundary currents and watermass transformation in marginal

seas. Journal of Physical Oceanography 34(5):1,197–1,213, https://doi.org/​10.1175/​

1520-0485(2004)034<1197:bcawti>2.0.co;2.

Stommel, H. 1961. Thermohaline convection with two stable regimes of flow.

Tellus 13(2):224–230.

Straneo, F., and F. Saucier. 2008. The outflow from Hudson Strait and its contribution

to the Labrador Current. Deep Sea Research Part I 55(8):926–946, https://doi.org/​

10.1016/j.dsr.2008.03.012.

Süfke, F., M. Gutjahr, L.D. Keigwin, B. Reilly, L. Giosan, and J. Lippold. 2022.

Arctic drainage of Laurentide Ice Sheet meltwater throughout the past 14,700

years. Communications Earth & Environment 3(1):98, https://doi.org/10.1038/

s43247-022-00428-3.

Sumata, H., L. de Steur, D.V. Divine, M.A. Granskog, and S. Gerland. 2023. Regime

shift in Arctic Ocean sea ice thickness. Nature 615(7952):443–449, https://doi.org/​

10.1038/s41586-022-05686-x.

Talley, L. 2013. Closure of the global overturning circulation through the Indian, Pacific,

and Southern Oceans: Schematics and transports. Oceanography 26(1):80–97,

https://doi.org/10.5670/oceanog.2013.07.

Tarasov, L., and W.R. Peltier. 2002. Greenland glacial history and local geodynamic

consequences. Geophysical Journal International 150(1):198–229, https://doi.org/​

10.1046/j.1365-246x.2002.01702.x.

Tarasov, L., and W.R. Peltier. 2005. Arctic freshwater forcing of the Younger Dryas cold

reversal. Nature 435(7042):662–665, https://doi.org/10.1038/nature03617.

Tarasov, L., A.S. Dyke, R.M. Neal, and W.R. Peltier. 2012. A data-calibrated distribution of

deglacial chronologies for the North American ice complex from glaciological mod-

eling. Earth and Planetary Science Letters 315:30–40, https://doi.org/10.1016/​j.epsl.​

2011.09.010.

Teller, J.T., D.W. Leverington, and J.D. Mann. 2002. Freshwater outbursts to the oceans

from glacial Lake Agassiz and their role in climate change during the last degla-

ciation. Quaternary Science Reviews 21(8–9):879–887, https://doi.org/10.1016/

s0277-​3791(01)00145-7.

Terhaar, J., L. Vogt, and N.P. Foukal. 2025. Atlantic overturning inferred from air-sea

heat fluxes indicates no decline since the 1960s. Nature Communications 16(1):222,

https://doi.org/10.1038/s41467-024-55297-5.

The IMBIE Team. 2019. Mass balance of the Greenland Ice Sheet from 1992 to 2018.

Nature 579(7798):233–239, https://doi.org/10.1038/s41586-019-1855-2.

Thiagarajan, N., A.V. Subhas, J.R. Southon, J.M. Eiler, and J.F. Adkins. 2014. Abrupt

pre-Bolling-Allerod warming and circulation changes in the deep ocean.

Nature 511:75–78, https://doi.org/10.1038/nature13472.

Thornalley, D., I.N. McCave, and H. Elderfield. 2010. Freshwater input and abrupt degla-

cial climate change in the North Atlantic. Paleoceanography 25(1), https://doi.org/​

10.1029/2009PA001772.

Thornalley, D.J.R., D.W. Oppo, P. Ortega, J.I. Robson, C.M. Brierley, R. Davis, I.R. Hall,

P. Moffa-Sanchez, N.L. Rose, P.T. Spooner, and others. 2018. Anomalously weak

Labrador Sea convection and Atlantic overturning during the past 150 years.

Nature 556(7700):227–230, https://doi.org/10.1038/s41586-018-0007-4.

Tjallingii, R., M. Claussen, J.-B. W. Stuut, J. Fohlmeister, A. Jahn, T. Bickert, F. Lamy,

and U. Röhl. 2008. Coherent high- and low-latitude control of the northwest African

hydrological balance. Nature Geoscience 1(10):670–675, https://doi.org/10.1038/

ngeo289.

Trenberth, K.E., Y. Zhang, J.T. Fasullo, and L. Cheng. 2019. Observation-based esti-

mates of global and basin ocean meridional heat transport time series. Journal of

Climate 32(14):4,567–4,583, https://doi.org/10.1175/jcli-d-18-0872.1.

Valdes, P. 2011. Built for stability. Nature Geoscience 4:414–416, https://doi.org/10.1038/

ngeo1200.

Volkov, D.L., R.H. Smith, R.F. Garcia, D.A. Smeed, B.I. Moat, W.E. Johns, and

M.O. Baringer. 2024. Florida Current transport observations reveal four decades

of steady state. Nature Communications 15(1):7780, https://doi.org/10.1038/

s41467-024-51879-5.

Wang, Y.J., H. Cheng, R.L. Edwards, Z. An, J.Y. Wu, C.-C. Shen, and J.A. Dorale. 2001.

A high-resolution absolute-dated Late Pleistocene monsoon record from Hulu cave,

China. Science 294(5550):2,345–2,348, https://doi.org/10.1126/science.1064618.

Weiffenbach, J.E., M.L.J. Baatsen, H.A. Dijkstra, A.S. von der Heydt, A. Abe-Ouchi,

E.C. Brady, W.-L. Chan, D. Chandan, M.A. Chandler, C. Contoux, and others.

2023. Unraveling the mechanisms and implications of a stronger mid-Pliocene

Atlantic Meridional Overturning Circulation (AMOC) in PlioMIP2. Climate of the

Past 19(1):61–85, https://doi.org/10.5194/cp-19-61-2023.

Wilson, D.J., A.M. Piotrowski, A. Galy, and J.A. Clegg. 2013. Reactivity of neodymium

carriers in deep sea sediments: Implications for boundary exchange and paleocean-

ography. Geochimica et Cosmochimica Acta 109:197–221, https://doi.org/10.1016/​

j.gca.2013.01.042.

Yeager, S., F. Castruccio, P. Chang, G. Danabasoglu, E. Maroon, J. Small, H. Wang,

L. Wu, and S. Zhang. 2021. An outsized role for the Labrador Sea in the multidecadal

variability of the Atlantic overturning circulation. Science Advances 7(41):eabh3592,

https://doi.org/10.1126/sciadv.abh3592.

Yu, E.F., R. François, and M.P. Bacon. 1996. Similar rates of modern and last-​

glacial ocean thermohaline circulation inferred from radiochemical data.

Nature 379:689–694, https://doi.org/10.1038/379689a0.

Zarriess, M., and A. Mackensen. 2011. Testing the impact of seasonal phytode-

tritus deposition on δ13C of epibenthic foraminifer Cibicidoides wuellerstorfi:

A 31,000 year high-resolution record from the northwest African continental slope.

Paleoceanography 26(2), https://doi.org/10.1029/2010pa001944.

Zhang, X., G. Lohmann, G. Knorr, and C. Purcell. 2014. Abrupt glacial climate shifts con-

trolled by ice sheet changes. Nature 512(7514):290–294, https://doi.org/10.1038/

nature13592.

Zhang, X., G. Knorr, G. Lohmann, and S. Barker. 2017. Abrupt North Atlantic circula-

tion changes in response to gradual CO2 forcing in a glacial climate state. Nature

Geoscience 10(7):518–523, https://doi.org/10.1038/ngeo2974.

Zhao, N., O. Marchal, L. Keigwin, D. Amrhein, and G. Gebbie. 2018. A synthesis

of deglacial deep-sea radiocarbon records and their (In)consistency with mod-

ern ocean ventilation. Paleoceanography and Paleoclimatology 33(2):128–151,

https://doi.org/10.1002/2017pa003174.

Zhou, Y., J.F. McManus, A.W. Jacobel, K.M. Costa, S. Wang, and B.A. Caraveo. 2021.

Enhanced iceberg discharge in the western North Atlantic during all Heinrich events

of the last glaciation. Earth and Planetary Science Letters 564:116910, https://doi.org/​

10.1016/j.epsl.2021.116910.

Zhou, Y., and J.F. McManus. 2024. Heinrich event ice discharge and the fate of

the Atlantic Meridional Overturning Circulation. Science 384(6699):983–986,

https://doi.org/​10.1126/science.adh8369.

ACKNOWLEDGMENTS

This work was supported by the Anonymous Trustee Early Career Fellowship

(SKVH), the Early Career Scientist Endowed Fund at the Woods Hole Oceanographic

Institution (NPF), grant 2123128 from the National Science Foundation (NPF), the

James E. and Barbara V. Moltz Early Career Science Fellowship (KMC), and the WHOI

Investment in Science Program (DWO). We would also like to acknowledge helpful

comments from three anonymous reviewers that significantly improved our paper.

AUTHORS

Sophia K.V. Hines (shines@whoi.edu), Department of Marine Chemistry and

Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, USA.

Nicholas P. Foukal, Department of Physical Oceanography, Woods Hole

Oceanographic Institution, Woods Hole, MA, USA, now at Skidaway Institute of

Oceanography, University of Georgia, Savannah, GA, USA. Kassandra M. Costa,

Delia W. Oppo, Olivier Marchal, Lloyd D. Keigwin, and Alan Condron, Department

of Geology and Geophysics, Woods Hole Oceanographic Institution,

Woods Hole, MA, USA.

ARTICLE CITATION

Hines, S.K.V., N.P. Foukal, K.M. Costa, D.W. Oppo, O. Marchal, L.D. Keigwin, and

A. Condron. 2025. Is there robust evidence for freshwater-driven AMOC changes?

A synthesis of data, models, and mechanisms. Oceanography 38(3):12–23,

https://doi.org/10.5670/oceanog.2025.e301.

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