Abstract
Two main hypotheses compete to explain global cooling and the abrupt growth of the Antarctic ice sheet across the Eocene–Oligocene transition about 34 million years ago: thermal isolation of Antarctica due to southern ocean gateway opening1,2,3,4, and declining atmospheric CO2 (refs 5, 6). Increases in ocean thermal stratification and circulation in proxies across the Eocene–Oligocene transition have been interpreted as a unique signature of gateway opening2,4, but at present both mechanisms remain possible. Here, using a coupled ocean–atmosphere model, we show that the rise of Antarctic glaciation, rather than altered palaeogeography, is best able to explain the observed oceanographic changes. We find that growth of the Antarctic ice sheet caused enhanced northward transport of Antarctic intermediate water and invigorated the formation of Antarctic bottom water, fundamentally reorganizing ocean circulation. Conversely, gateway openings had much less impact on ocean thermal stratification and circulation. Our results support available evidence that CO2 drawdown—not gateway opening—caused Antarctic ice sheet growth, and further show that these feedbacks in turn altered ocean circulation. The precise timing and rate of glaciation, and thus its impacts on ocean circulation, reflect the balance between potentially positive feedbacks (increases in sea ice extent and enhanced primary productivity) and negative feedbacks (stronger southward heat transport and localized high-latitude warming). The Antarctic ice sheet had a complex, dynamic role in ocean circulation and heat fluxes during its initiation, and these processes are likely to operate in the future.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Kennett, J. P. Cenozoic evolution of Antarctic glaciations, the circum-Antarctic ocean and their impact on global paleoceanography. J. Geophys. Res. 82, 3843–3860 (1977)
Cramer, B. S., Toggweiler, J. R., Wright, J. D., Katz, M. E. & Miller, K. G. Ocean overturning since the Late Cretaceous: inferences from a new benthic foraminiferal isotope compilation. Paleoceanography 24, PA4216 (2009)
Katz, M. E. et al. Stepwise transition from the Eocene greenhouse to the Oligocene icehouse. Nature Geosci. 1, 329–334 (2008)
Katz, M. E. et al. Impact of Antarctic circumpolar current development on Late Paleogene ocean structure. Science 332, 1076–1079 (2011)
DeConto, R. M. & Pollard, D. Rapid Cenozoic glaciation of Antarctica induced by declining atmospheric CO2 . Nature 421, 245–249 (2003)
Pagani, M. et al. The role of carbon dioxide during the onset of Antarctic glaciation. Science 334, 1261–1264 (2011)
Liu, Z. et al. Global cooling during the Eocene–Oligocene climate transition. Science 323, 1187–1190 (2009)
Houben, A. J. et al. Reorganization of Southern Ocean plankton ecosystem at the onset of Antarctic glaciation. Science 340, 341–344 (2013)
Toggweiler, J. R. & Samuels, B. Effect of Drake Passage on the global thermohaline circulation. Deep Sea Res. Oceanogr. Res. Pap. 42, 477–500 (1994)
Sijp, W. P., England, M. H. & Toggweiler, J. R. Effect of ocean gateway changes under greenhouse warmth. J. Clim. 22, 6639–6652 (2009)
Pearson, P. N., Foster, G. L. & Wade, B. S. Atmospheric carbon dioxide through the Eocene–Oligocene climate transition. Nature 461, 1110–1113 (2009)
Pollard, D. & DeConto, R. M. Hysteresis in Cenozoic Antarctic ice sheet variations. Glob. Planet. Change 45, 9–21 (2005)
Huber, M. & Nof, D. The ocean circulation in the southern hemisphere and its climatic impacts in the Eocene. Palaeogeogr. Palaeoclimatol. Palaeoecol. 231, 9–28 (2006)
Lefebvre, V., Donnadieu, Y., Sepulchre, P., Swingedouw, D. & Zhang, Z. S. Deciphering the role of southern gateways and carbon dioxide on the onset of the Antarctic Circumpolar Current. Paleoceanography 27, PA4201 (2012)
Lawver, L. A., Gahagan, L. M. & Dalziel, I. W. D. in Tectonic, Climatic, and Cryospheric Evolution of the Antarctic Peninsula (eds Anderson, J. B. & Wellner, J. S. ) 5–33 (Am. Geophys. Un. Spec. Publ. 63, 2011)
Coxall, H. K., Wilson, P. A., Pälike, H., Lear, C. H. & Backman, J. Rapid stepwise onset of Antarctic glaciation and deeper calcite compensation in the Pacific Ocean. Nature 433, 53–57 (2005)
Miller, K. G. et al. in The Late Eocene Earth? Hothouse, Icehouse, and Impacts (eds Koeberl, C. & Montanari, A. ) 169–178 (Geol. Soc. Am. Spec. Pap. 452, 2009)
Lear, C. H., Bailey, T. R., Pearson, P. N., Coxall, H. K. & Rosenthal, Y. Cooling and ice growth across the Eocene–Oligocene transition. Geology 36, 251–254 (2008)
Bohaty, S. M., Zachos, J. C. & Delaney, L. M. Foraminiferal Mg/Ca evidence for Southern Ocean cooling across the Eocene–Oligocene transition. Earth Planet. Sci. Lett. 317–318, 251–261 (2012)
Hren, M. T. et al. Terrestrial cooling in Northern Europe during the Eocene–Oligocene transition. Proc. Natl Acad. Sci. USA 110, 7562–7567 (2013)
Huber, M. & Caballero, R. The early Eocene equable climate problem revisited. Clim. Past 7, 603–633 (2011)
Goldner, A., Huber, M. & Caballero, R. Does Antarctic glaciation cool the world? Clim. Past 9, 173–189 (2013)
Sijp, W. P., England, M. H. & Huber, M. Effect of the deepening of the Tasman Gateway on the global ocean. Paleoceanography 26, PA4207 (2011)
DeConto, R., Pollard, D. & Harwood, D. Sea ice feedback and Cenozoic evolution of Antarctic climate and ice sheets. Paleoceanography 22, PA3214 (2007)
Foster, G. L. & Rohling, E. J. Relationship between sea level and climate forcing by CO2 on geological timescales. Proc. Natl Acad. Sci. USA 110, 1209–1214 (2013)
Hill, D. J. et al. Paleogeographic controls on the onset of the Antarctic circumpolar current. Geophys. Res. Lett. 40, 5199–5204 (2013)
Bijl, P. K. et al. Eocene cooling linked to early flow across the Tasmanian Gateway. Proc. Natl Acad. Sci. USA 110, 9645–9650 (2013)
Lyle, M., Gibbs, S., Moore, T. C., Jr & Rea, D. K. Late Oligocene initiation of the Antarctic circumpolar current: evidence from the South Pacific. Geology 35, 691–694 (2007)
Dalziel, I. W. D. Drake Passage and the Scotia arc: a tortuous space–time gateway for the Antarctic Circumpolar Current. Geology 42, 367–368 (2014)
Zachos, J. C. & Kump, L. R. Carbon cycle feedbacks and the initiation of Antarctic glaciation in the earliest Oligocene. Global Planet. Change 47, 51–66 (2005)
Gent, P. R. et al. The Community Climate System Model version 4. J. Clim. 24, 4973–4991 (2011)
Lawrence, D. M. et al. The CCSM4 land simulation, 1850–2005: assessment of surface climate and new capabilities. J. Clim. 25, 2240–2260 (2012)
Bitz, C. M. et al. Climate sensitivity of the community climate system model version 4. J. Clim. 25, 3053–3070 (2012)
Large, G. W., Danabasoglu, G., McWilliams, J. C., Gent, P. R. & Bryan, F. O. Equatorial circulation in a global ocean climate model with anisotropic horizontal viscosity. J. Phys. Oceanogr. 31, 518–536 (2001)
Gent, P. R. & McWilliams, J. C. Isopycnal mixing in ocean circulation models. J. Phys. Oceanogr. 20, 150–155 (1990)
Jochum, M. Impact of latitudinal variations in vertical diffusivity on climate simulations. J. Geophys. Res. 114, C01010 (2009)
Ferrari, R. & Wunsch, C. Ocean circulation kinetic energy: reservoirs, sources, and sinks. Annu. Rev. Fluid Mech. 41, 253–282 (2009)
Danabasoglu, G., Ferrari, R. & McWilliams, J. C. Sensitivity of an ocean general circulation model to a parameterization of near-surface eddy fluxes. J. Clim. 21, 1192–1208 (2008)
Fox-Kemper, B., Ferrari, R. & Hallberg, R. Parameterization of mixed layer eddies. I. Theory and diagnosis. J. Phys. Oceanogr. 38, 1145–1165 (2008)
Large, W. G. & Danabasoglu, G. Attribution and impacts of upper-ocean biases in CCSM3. J. Clim. 19, 2325–2346 (2006)
Ali, J. R. & Huber, M. Mammalian biodiversity on Madagascar controlled by ocean currents. Nature 463, 653–656 (2010)
Heavens, N. G., Shields, C. A. & Mahowald, N. M. A paleogeographic approach to aerosol prescription in simulations of deep time climate. J. Adv. Model. Earth Syst. 4, M11002 (2012)
Wilson, D. S., Pollard, D., DeConto, R. M., Jamieson, S. S. R. & Luyendyk, B. P. Initiation of the West Antarctic Ice Sheet and estimates of total Antarctic ice volume in the earliest Oligocene. Geophys. Res. Lett. 40, 4305–4309 (2013)
Eldrett, J. S., Greenwood, D. R., Harding, I. C. & Huber, M. Increased seasonality through the Eocene to Oligocene transition in northern high latitudes. Nature 459, 969–973 (2009)
Hill, D. J. et al. Paleogeographic controls on the onset of the Antarctic circumpolar current. Geophys. Res. Lett. 40, 5199–5204 (2013)
Broecker, W. S. The salinity contrast between the Atlantic and Pacific oceans during glacial time. Paleoceanography 4, 207–212 (1989)
Knorr, G. & Lohmann, G. Climate warming during Antarctic ice sheet expansion at the Middle Miocene transition. Nature Geosci. 7, 376–381 (2014)
Acknowledgements
A.G. was funded by a Graduate Assistance in Areas of National Need (GAANN) fellowship through the Computational Sciences and Engineering Program at Purdue University. M.H. and N.H. were supported by National Science Foundation (NSF) P2C2 grants OCE 0902882 and EAR 1049921. Computing was performed on Rosen Center for Advanced Computing resources on the Hansen and Coates cluster at Purdue University. Proxy records were compiled from refs 2, 4, and specific records and references are described in extended data. The CESM model is supported and developed by the National Center for Atmospheric Research, which is supported by the NSF.
Author information
Authors and Affiliations
Contributions
A.G. conducted the EOT simulations, recompiled the proxy record data and wrote the manuscript. N.H. and M.H. helped compile the proxy record data and helped with writing the manuscript.
Corresponding authors
Ethics declarations
Competing interests
The authors declare no competing financial interests.
Extended data figures and tables
Extended Data Figure 1 Ocean temperature and δ18O anomalies.
a–c, Zonally averaged temperature anomalies (°C) averaged over all longitudes: Glaciated minus unglaciated cases (CO2 constant at 560 p.p.m.) (a), 1,120 minus 560 p.p.m. CO2 cases (both unglaciated) (b), and unglaciated case with 1,120 p.p.m. CO2 minus glaciated case with 560 p.p.m. CO2 (c). d–f, δ18O comparisons (per mil) zonally averaged over the Atlantic basin; otherwise as in a–c.
Extended Data Figure 2 Ocean temperature and δ18O anomalies in Atlantic Ocean basin due to Southern Ocean gateway opening.
a, Temperature anomaly (°C) for both gateways opened minus both gateways closed. b, Temperature anomaly for DP and TG closed minus DP open and TG closed. c, Temperature anomaly for DP and TG open minus TG closed DP open. d–f, As in a–c, except for δ18O.
Extended Data Figure 3 Absolute sea-ice and anomalous sea surface temperature.
a, b, Sea ice fraction for glaciated (a) and unglaciated (b) cases. c, Glaciated minus unglaciated sea surface temperature anomaly. All simulations with 1,120 p.p.m. CO2.
Extended Data Figure 4 Absolute salinity fields.
Salinity (colour contour) and salinity flux (vectors) for glaciated late Eocene (a) and unglaciated cases (b) at 1,120 p.p.m. CO2.
Extended Data Figure 5 Absolute sea level pressure and surface wind.
Sea level pressure (colour contour) and surface wind (vectors) for glaciated (a) and unglaciated (b) cases at 1,120 p.p.m. CO2.
Extended Data Figure 6 Absolute Ekman pumping and transport.
Ekman pumping contour and Ekman transport overlaid as vectors for glaciated (a) and unglaciated (b) cases at 1,120 p.p.m. CO2. See the calculations for Ekman pumping and transport in Methods.
Extended Data Figure 7 Absolute ocean currents.
Zonally averaged ocean currents (meridional and vertical) across the Atlantic Ocean. The vertical ocean velocities are scaled by a constant coefficient (500) for plotting purposes. Glaciated (a) and unglaciated (b) cases at 1,120 p.p.m. CO2.
Extended Data Figure 8 Meridional overturning circulation.
Zonally averaged meridional overturning circulation anomaly for glaciated (a) unglaciated, (b) and glaciated minus unglaciated (c) case anomaly at 1,120 p.p.m. CO2.
Extended Data Figure 9 Depth–latitude plot for the non-interpolated and interpolated δ18O proxy record anomalies.
a, Raw δ18O anomalies. b, Interpolated δ18O anomalies (see Extended Data Table 1).
Rights and permissions
About this article
Cite this article
Goldner, A., Herold, N. & Huber, M. Antarctic glaciation caused ocean circulation changes at the Eocene–Oligocene transition. Nature 511, 574–577 (2014). https://doi.org/10.1038/nature13597
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/nature13597
This article is cited by
-
Oxygenated deep waters fed early Atlantic overturning circulation upon Antarctic glaciation
Nature Geoscience (2023)
-
Strength and variability of the Oligocene Southern Ocean surface temperature gradient
Communications Earth & Environment (2022)
-
Calcareous nannofossil biostratigraphy and paleoenvironment of the Eocene–Oligocene interval in the Pabdeh Formation in southwestern Iran
International Journal of Earth Sciences (2022)
-
Eocene to Oligocene terrestrial Southern Hemisphere cooling caused by declining pCO2
Nature Geoscience (2021)
-
Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling
Nature Communications (2021)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.