Climate of the Past www.clim-past.net 1814-9324 1814-9332 5 2 2009 10.5194/cp-5-269-2009 http://www.clim-past.net/5/269/2009/ http://www.clim-past.net/5/269/2009/cp-5-269-2009.html http://www.clim-past.net/5/269/2009/cp-5-269-2009.pdf 269 283 2009-06-30 Mid-Pliocene shifts in ocean overturning circulation and the onset of Quaternary-style climates M. Sarnthein ms@gpi.uni-kiel.de G. Bartoli M. Prange A. Schmittner B. Schneider M. Weinelt N. Andersen D. Garbe-Schönberg Institute for Geosciences, University of Kiel, 24098 Kiel, Germany Institute for Geology and Paleontology, University of Innsbruck, 6020, Innsbruck, Austria Geologisches Institut, ETH Zuerich, 8092 Zurich, Switzerland MARUM Center for Marine Environmental Sciences and Faculty of Geosciences, University of Bremen, 28334 Bremen, Germany College of Ocean and Atmospheric Sciences, Oregon State University, Corvallis OR 97331-5503, USA Leibniz Laboratory, University of Kiel, 24098 Kiel, Germany Invited contribution by M. Sarnthein, recipient of the EGU Milutin Milankovic Medal 2006. A major tipping point of Earth's history occurred during the mid-Pliocene: the onset of major Northern-Hemisphere Glaciation (NHG) and of pronounced, Quaternary-style cycles of glacial-to-interglacial climates, that contrast with more uniform climates over most of the preceding Cenozoic and continue until today (Zachos et al., 2001). The severe deterioration of climate occurred in three steps between 3.2 Ma (warm MIS K3) and 2.7 Ma (glacial MIS G6/4) (Lisiecki and Raymo, 2005). Various models (sensu Driscoll and Haug, 1998) and paleoceanographic records (intercalibrated using orbital age control) suggest clear linkages between the onset of NHG and the three steps in the final closure of the Central American Seaways (CAS), deduced from rising salinity differences between Caribbean and the East Pacific. Each closing event led to an enhanced North Atlantic meridional overturning circulation and this strengthened the poleward transport of salt and heat (warmings of +2–3°C) (Bartoli et al., 2005). Also, the closing resulted in a slight rise in the poleward atmospheric moisture transport to northwestern Eurasia (Lunt et al., 2007), which probably led to an enhanced precipitation and fluvial run-off, lower sea surface salinity (SSS), and an increased sea-ice cover in the Arctic Ocean, hence promoting albedo and the build-up of continental ice sheets. Most important, new evidence shows that the closing of the CAS led to greater steric height of the North Pacific and thus doubled the low-saline Arctic Throughflow from the Bering Strait to the East Greenland Current (EGC). Accordingly, Labrador Sea IODP Site 1307 displays an abrupt but irreversible EGC cooling of 6°C and freshening by ~2 psu from 3.25/3.16–3.00 Ma, right after the first but still reversible attempt of closing the CAS. Alley, R. B., Clark, P. U., Huybrechts, P., and Joughin, I.: Ice-sheet and sea-level changes, Science, 310, 456–460, 2005. Bartoli, G., Sarnthein, M., and Weinelt, M.: Late Pliocene millennial-scale climate variability in the northern North Atlantic prior to and after the onset of Northern Hemisphere glaciation, Paleoceanogr., 21, PA4205, 1–15, 2006. Bartoli, G., Sarnthein, M., Weinelt, M., Erlenkeuser, H., Garbe-Schönberg, D., and Lea, D.: Final closure of Panama and the onset of northern hemisphere glaciation, Earth Planet. Sci. Lett., 237, 33–44, doi:10.1016/j.epsl.2005.06.020, 2005. Bryan, K.: A numerical method for the study of the circulation of the world ocean, J. Comp. Physics, 4, 347–376, 1969. Cane, M. A. and Molnar, P.: Closing of the Indonesian seaway as precursor to east African aridification around 3–4 million years ago, Nature, 411, 157–162, 2001. Coates, A. G., Collins, L. S., Aubry, M.-P., and Berggren, W. A.: The geology of the Darien, Panama, and the late Miocene-Pliocene collision of the Panama arc with northwestern South America, Geol. Soc. Amer. Bull., 116, 1327–1344, doi:10.1130/B25275.1, 2004. Darby, D. A.: Arctic perennial ice cover over the last 14 million years, Paleoceanogr., 23, PA1S07, doi:10.1029/2007PA001479, 2008. DeConto, R. M., Pollard, D., Wilson, P. A., Pälike, H., Lear, C. H., and Pagani, M.: Thresholds for Cenozoic bipolar glaciation, Nature, 455, 652–656, 2008. Driscoll, N. W. and Haug, G. H.: A short circuit in thermohaline circulation: A cause for Northern Hemisphere Glaciation?, Science, 282, 436–438, 1998. Eisenman, I., Untersteiner, N., and Wettlaufer, J. S.: On the reliability of simulated Arctic sea ice in global climate models, Geophys. Res. Lett., 34, L10501, doi:10.1029/2007GL029914, 2007. Eldrett, J., Harding, I. C., Wilson, P. A., Butler, E., and Roberts, A. P.: Continental ice in Greenland during the Eocene and Oligocene, Nature, 446, 176–179, doi:10.1038/nature05591, 2007. Expedition 303 Scientists, Site U1307, in: Proc. IODP, edited by: Channell, J. E. T., Kanamatsu, T., Sato, T., Stein, R., Alvarez Zarikian, C. A., Malone, M. J., and the Expedition 303/306 Scientists, 303/306, College Station TX (Integrated Ocean Drilling Program Management International, Inc.), doi:10.2204/iodp.proc.303306.107, 2006. Foster, G. L., Seki, O., Schmidt, D. N., Kawamura, K., and Pancost, R.: Plio-Pleistocene pCO₂ – a multiproxy approach using alkenone and boron based carbonate system proxies, Eos Trans. AGU, 89(53), Fall Meet. Suppl. Abstract PP41D-1484, 2008. Frank, M., Backman, J., Jacobsson, M., Moran, K., et al.: Beryllium isotopes in central Arctic Ocean sediments over the past 12.3 million years: Stratigraphic and paleoclimatic implications, Paleoceanogr., 23, PA1S02, doi:10.1029/2007/PA00147, 2008. Gordon, C., Cooper, C., Senior, C. A., Banks, H., Gregory, J. M., Johns, T. C., Mitchell, J. F. B., and Wood, R. A.: The simulation of SST, sea ice extents and ocean heat transports in a version of the Hadley Centre coupled model without flux adjustments, Clim. Dynam., 16, 147–168, 2000. Groeneveld, J.: Effect of the Pliocene closure of the Panamaian gateway on Caribbean and east Pacific sea surface temperatures and salinities by applying combined Mg/Ca and $\delta ^18$O measurements (5.6–2.2 Ma). PhD Thesis, University of Kiel, 2005. Groeneveld, J., Steph, S., Tiedemann, R., Garbe-Schönberg, D., Nürnberg, D., and Sturm, A.: Pliocene mixed-layer oceanography for Site 1241 using combined Mg/Ca and $\delta ^18$O analyses of \textitGlobigerina sacculifer, in: Proc. ODP, Sci. Results, 202, edited by: Tiedemann, R., Mix, A. C., Richter, C., and Ruddiman, W. F., College Station, TX (Ocean Drilling Program), 1–27, doi:10.2973/odp.proc.sr.202.209. 2006. Groeneveld, J., Nürnberg, D., Tiedemann, R., Reichart, G.-J., Steph, S., Reuning, L., D. Crudeli, D., and Mason, P.: Foraminiferal Mg/Ca increase in the Caribbean during the Pliocene: Western Atlantic Warm Pool formation, salinity influence, or diagenetic overprint?, Geochem. Geophys. Geosyst., 9(1), Q01P23, doi:10.1029/2006GC001564, 2008. Haug, G. H., Tiedemann, R., Zahn, R., and Ravelo, A. C.: Role of Panama uplift on oceanic freshwater balance, Geology, 29, 207–210, 2001. Huybers, P. and Molnar, P.: Tropical cooling and the onset of North American glaciation, Clim. Past, 3, 549–557, 2007. Hvidegaard, S. M. and Sandberg, L.: Study of elevation changes along a profile crossing the Greenland Ice Sheet, Poster EGU Vienna, EGU2009-8790, 2009. Huybrechts, P., Gregory, J., Janssens, I., and Wild, M.: Modelling Antarctic and Greenland volume changes during the 20th and 21st centuries forced by GCM time slice integrations, Global Planet. Change, 42, 83–105, 2004. Jansen, E., Fronval, T., Ranck, F., and Channell, J. E. T.: Pliocene-Pleistocene ice rafting history and cyclicity in the Nordic Seas during the last 3.5 Myr, Paleoceanogr., 15, 709–721, 2000. Kameo, K. and Sato, T.: Biogeography of Neogene calcareous nannofossils in the Caribbean and the eastern equatorial Pacific – floral response to the emergence of the Isthmus of Panama, Mar. Micropal., 39, 201–218, 2000. Kawamura, K., Parrenin, F., Lisiecki, L., Uemura, R., Vimeux, F., Severinghaus, J. P., Hutterli, M. A., et al.: Northern Hemisphere forcing of climatic cycles in Antarctica over the past 360,000 years, Nature, 448, 912–927, 2007. Keigwin, L. D.: Isotopic paleoceanography of the Caribbean and East Pacific: Role of Panama uplift in Late Neogene time, Science, 217, 350–353, 1982. Kleiven, H. F., Jansen, E., Fronval, T., and Smith, T. M.: Intensification of Northern Hemisphere glaciations in the circum Atlantic region (3.5–2.4 Ma), Paleogeogr. Paleoclimatol. Paleoecol., 184, 213–223, 2002. Klocker, A., Prange, M., and Schulz, M.: Testing the influence of the Central American Seaway on orbitally forced northern hemisphere glaciation: Geophys. Res. Lett., 32, L03703, doi:10.1029/2004GL021564, 2005. Kürschner, W. M., Van der Burgh, J., Visscher, H., and Dilcher, D. L.: Oak leaves as biosensors of late Neogene and early Pleistocene paleoatmospheric CO₂ concentrations, Mar. Micropal., 27, 299–312, 1996. Lacasse, C. and van den Bogaard, P.: Enhanced airborne dispersal of silicic tephras during the onset of Northern Hemisphere glaciations, from 6 to 0 Ma records of explosive volcanism and climate change in the subpolar North Atlantic, Geology, 30, 623–626, 2002. Laskar, J., Robutel, P., Joutel, F., Gastineau, M., Correia, A. C. M., and Levrard, B.: A long-term numerical solution for the insolation quantities of the Earth, Astronomy and Astrophysics manuscript no. La'2004, 1–26, 2004. Lawrence, K., Liu, Z., and Herbert, T.: Evolution of the eastern tropical Pacific through Plio-Pleistocene glaciations, Science, 312, 79–83, 2006. Lisiecki, L. E., and Raymo, M. E.: A Pliocene-Pleistocene stack of 57 globally distributed benthic $\delta ^18$O records, Paleoceanogr., 20, PA1003, doi:10.1029/2004PA001071, 2005. Lunt, D. J., Foster, G. L., Haywood, A. M., and Stone, E. J.: Late Pliocene Greenland glaciation controlled by a decline in atmospheric CO₂ levels, Nature, 454, 1102–1105, 2008. Lunt, D. J., Valdes, P. J., Haywood, A. M., and Rutt, I. C.: Closure of the Panama Seaway during the Pliocene: implications for climate and Northern Hemisphere glaciation, Clim. Dynam., 30, 1–18, doi:10.1007/s00382-0070265-6, 2007. Maier-Reimer, E., Mikolajewicz, U., and Crowley, T.: Ocean general circulation model sensitivity experiment with an open Central American Isthmus, Paleoceanogr., 5, 349–366, 1990. Maslin, M. A., Haug, G., Sarnthein, M., Tiedemann, R., Erlenkeuser, H., and Stax, R.: Northwest Pacific Site 882: The initiation of Northern Hemisphere Glaciation, Sci. Res. ODP Leg, 145, 315–332, 1995. Maslin, M., Haug, G., Sarnthein, M., and Tiedemann, R.: The progressive intensification of Northern Hemisphere glaciation as seen from the North Pacific, ICES-Geol. Rdsch. 85, 452–465, 1996. Meschede, M. and Barckhausen, U.: Twin hotspot tracks and ridge jumps: the evolution of the Cocos Nazca Spreading Center, in: ODP's Greatest Hits, edited by: White, K. and Urquhart, E., Vol. 2, 1 pp., available from: http://www.oceandrilling.org/greatest_hits2/PDFs/meschedehotspot.pdf, 2002. Molnar, P.: Closing of the Central American Seaway and the Ice Age: A critical review, Paleoceanogr., 23, PA2201, doi:10.1029/2007PA001574, 2008. Murdock, T. Q., Weaver, A. J., and Fanning, A. F.: Paleoclimatic response of the closing of the Isthmus of Panama in a coupled ocean-atmosphere model, Geophys. Res. Lett., 24, 253–256, 1997. Pagani, M., Zachos, J. C., Freeman, K. H., Tipple, B., and Bohaty, B.: Marked decline in atmospheric carbon dioxide concentrations during the Paleogene, Science, 309, 600–603, 2005. Prange, M.: The low-resolution CCSM2 revisited: new adjustments and a present-day control run, Ocean Sci., 4, 151–181, 2008. Ravelo, A. C., Dekens, P. S., and McCarthy, M.: Evidence for El Nino-like conditions during the Pliocene, GSA Today, 16(3), 4–11, 2006. Raymo, M. E., Grant, B., Horowitz, M., and Rau, G. H.: Mid-Pliocene warmth: stronger greenhouse and stronger conveyor, Mar. Micropaleont., 27, 313–326, 1996. Schneider, B. and Schmittner, A.: Simulating the impact of the Panamanian seaway closure on ocean circulation, marine productivity and nutrient cycling, Earth Planet. Sci. Lett., 246, 367–380, doi:10.1016/j.epsl.2006.04.028, 2006. Shackleton, N. J., Backman, J., Zimmerman, H., et al.: Oxygen isotope calibration of the onset of ice-rafting and history of glaciation in the North Atlantic region, Nature, 307, 620–623, 1984. Simstich, J., Sarnthein, M., and Erlenkeuser, H.: Paired $\delta ^18$O signals of \textitN. pachyderma (s) and \textitT. quinqueloba show thermal stratification structure in the Nordic Seas, Mar. Micropal., 48, 107–125, 2002. Steph, S., Tiedemann, R., Prange, M., Groeneveld, J., Nürnberg, D., Reuning, L., Schulz, M., and Haug, G.: Changes in Caribbean surface hydrography during the Pliocene shoaling of the Central American Seaway, Paleoceanogr., 21, PA4221, doi:10.1029/2004PA001092, 2006. Stein, R.: Arctic Ocean Sediments – Processes, Proxies, and Paleoenvironment, in: Developments in Marine Geology, vol. 2, Elsevier, 1–592, 2008. Tiedemann, R., Sarnthein, M., and Shackleton, N. J.: Astronomic timescale for the Pliocene Atlantic $\delta ^18$O and dust flux records of ODP Site 659, Paleoceanogr., 9, 619–638, 1994. Tiedemann, R., Sturm, A., Steph, S., Lund, S. P., and Stoner, J. S.: Astronomicaslly calibrated timescales from 6 to 2.5 Ma and benthic isotope stratigraphies, Sites 1236, 1237, 1239, and 1241, in: Proc. ODP, Sci. Results, 202, edited by: Tiedemann, R., Mix, A. C., Richter, C., and Ruddiman, W. F., College Station, TX (Ocean Drilling Program), 1–69, doi:10.2973/odp.proc.sr.202.210.2007, 2007. Toniazzo, T., Gregory, J. M., and Huybrechts, P.: Climatic impact of a Greenland deglaciation and Its possible irreversibility, J. Climate, 17, 21–33, 2005. Wang, P. X., Tian, J., Cheng, X. R., et al.: Major Pleistocene stages in a carbon perspective: The South China Sea record and its comparison, Paleoceanogr., 19, PA4005, doi:10.1029/2003PA000991, 2004. Wang, P. X.: Global monsoon in a geological perspective, Chinese Science Bulletin, 54(7), 1113–1136, 2009. Weyl, P. K.: The role of the oceans in climate change; a theory of the ice ages, Meteorol. Monogr., 8, 37–62, 1968. Zachos, J., Pagani, M., Sloan,L., and Thomas, E.: Trends, rhythms, and aberrations in global climate 65 Ma to present, Science, 292, 686–693, 2001. Zachos, J., Dickens, G. R., and Zeebe, R. E.: An early Cenozoic perspective on greenhouse warming and carbon-cycle dynamics, Nature, 451, 279–283, 2008.