Climate of the Past
www.clim-past.net
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4
3
2008
10.5194/cp-4-191-2008
http://www.clim-past.net/4/191/2008/
http://www.clim-past.net/4/191/2008/cp-4-191-2008.html
http://www.clim-past.net/4/191/2008/cp-4-191-2008.pdf
191
203
2008-09-04
A modeling sensitivity study of the influence of the Atlantic meridional overturning circulation on neodymium isotopic composition at the Last Glacial Maximum
T. Arsouze
J.-C. Dutay
dutay@lsce.ipsl.fr
M. Kageyama
F. Lacan
R. Alkama
O. Marti
C. Jeandel
Laboratoire des Sciences du Climat et de l'Environnement (LSCE), CEA/CNRS/UVSQ/IPSL, Orme des Merisiers, Gif-Sur-Yvette, Bat 712, 91191 Gif sur Yvette cedex, France
Laboratoire d'Etudes en Géophysique et Océanographie Spatiale (LEGOS), CNES/CNRS/UPS/IRD, Observatoire Midi-Pyrénées, 14 av. E. Belin, 31400 Toulouse, France
Using a simple parameterisation that resolves the first order global Nd
isotopic composition (hereafter expressed as ε<sub>Nd</sub> in an
Ocean Global Circulation Model, we have tested the impact of different
circulation scenarios on the ε<sub>Nd</sub> in the Atlantic for the
Last Glacial Maximum (LGM), relative to a modern control run. Three
different LGM freshwater forcing experiments are performed to test for
variability in the ε<sub>Nd</sub> oceanic distribution as a function
of ocean circulation. Highly distinct representations of the ocean
circulation are generated in the three simulations, which drive significant
differences in ε<sub>Nd</sub>, particularly in deep waters of the
western part of the basin. However, at the LGM, the Atlantic is more
radiogenic than in the modern control run, particularly in the Labrador
basin and in the Southern Ocean. A fourth experiment shows that changes in
Nd sources and bathymetry drive a shift in the ε<sub>Nd</sub>
signature of the basin that is sufficient to explain the changes in the
ε<sub>Nd</sub> signature of the northern end-member (NADW or GNAIW
glacial equivalent) in our LGM simulations. All three of our LGM circulation
scenarios show good agreement with the existing intermediate depth
ε<sub>Nd</sub> paleo-data. This study cannot indicate the likelihood
of a given LGM oceanic circulation scenario, even if simulations with a
prominent water mass of southern origin provide the most conclusive results.
Instead, our modeling results highlight the need for more data from deep and
bottom waters from western Atlantic, where the ε<sub>Nd</sub> change
in the three LGM scenarios is the most important (up to 3 ε<sub>Nd</sub>. This would also aid more precise conclusions concerning the
evolution of the northern end-member ε<sub>Nd</sub> signature, and
thus the potential use of ε<sub>Nd</sub> as a tracer of past oceanic
circulation.
Abouchami, W., Galer, S. J. G., and Koschinsky, A.: Pb and Nd isotopes in NE Atlantic Fe-Mn crusts : Proxies for trace metal paleosources and paleocean circulation, Geochim. Cosmochim. Ac., 63, 1489–1505, 1999.
Albarede, F., Goldstein, S. L., and Dautel, D.: The neodymium isotopic composition in Mn nodules from the Southern and Indian Oceans, the global oceanic neodymium budget and their bearing on deep ocean circulation, Geochim. Cosmochim. Ac, 61, 1277–1291, 1997.
Alkama, R., Kageyama, M., and Ramstein, G.: Freshwater discharges in a simulation of the Last Glacial Maximum climate using improved river routing, Geophys. Res. Lett., 33, L21709, doi:10.1029/2006GL027746, 2006.
Alkama, R., Kageyama, M., Ramstein, G., and Marti, O.: Impact of a realistic river routing in coupled ocean-atmosphere simulations of the Last Glacial Maximum climate, Clim. Dynam., 30, 855–869, 2008.
Amakawa, H., Nozaki, Y., Alibo, D. S., Zhang, J., Fukugawa, K., and Nagai, H.: Neodymium isotopic variations in Northwest Pacific waters, Geochim. Cosmochim. Ac., 68, 715–727, 2004.
Arsouze, T., Dutay, J. C., Lacan, F., and Jeandel, C.: Modeling the neodymium isotopic composition with a global ocean circulation model, Chem. Geol., 239, 165–177, 2007.
Bayon, G., German, C. R., Boella, R. M., Milton, J. A., Taylor, R. N., and Nesbitt, R. W.: An improved method for extracting marine sediment fractions and its application to Sr and Nd isotopic analysis, Chem. Geol., 187, 179–199, 2002.
Broecker, W. S. and Denton, G. H.: The role of ocean-atmosphere reorganizations in glacial cycles, Geochim. Cosmochim. Ac., 53, 2465–2501, 1989.
Broecker, W. S.: Constraints on the glacial operation of the Atlantic Ocean's conveyor circulation, Israel J. Chem., 42, 1–14, 2002.
Charles, C. D. and Fairbanks, R. G.: Evidence from Southern Ocean sediments for the effect of North Atlantic deep-water flux on climate, Nature, 355, 416–419, 1992.
Curry, W. B. and Lohmann, G. P.: Reduced advection into Atlantic Ocean deep eastern basins during last glaciation maximum, Nature, 306, 577–580, 1983.
Curry, W. B. and Oppo, D. W.: Glacial water mass geometry and the distribution of delta C-13 of Sigma CO<sub>2</sub> in the western Atlantic Ocean, Paleoceanography, 20, PA1017, doi:10.1029/2004PA001021, 2005.
Duplessy, J. C., Shackleton, N. J., Fairbanks, R. G., Labeyrie, L., Oppo, D., and Kallel, N.: Deep water source variations during the last climatic cycle and their impact on the global deep water circulation, Paleoceanography, 3, 343–360, 1988.
Dutay, J. C., Bullister, J. L., Doney, S. C., Orr, J. C., Najjar, R., Caldeira, K., Campin, J. M., Drange, H., Follows, M., Gao, Y., Gruberi, N., Hecht, M. W., Ishida, A., Joos, F., Lindsay, K., Madec, G., Maier-Reimer, E., Marshall, J. C., Matear, R. J., Monfray, P., Mouchet, A., Plattner, G.-K., Sarmiento, J., Schlitzer, R., Slater, R., Totterdell, I. J., Weirig, M.-F., Yamanaka, Y., and Yool, A.: Evaluation of ocean model ventilation with CFC-11: comparison of 13 global ocean models, Ocean. model., 4, 89–120, 2002.
Elderfield, H., Hawkesworth, C. J., Greaves, M. J., and Calvert, S. E.: Rare earth element geochemistry of oceanic ferromanganese nodules and associated sediments, Geochim. Cosmochim. Ac., 29, 209–220, 1981.
Fichefet, T. and Maqueda, M. A. M.: Sensitivity of a global sea ice model to the treatment of ice thermodynamics and dynamics, J. Geophys. Res.-Oceans, 102, 12 609–12 646, 1997.
Foster, G. L., Vance, D., and Prytulak, J.: No change in the neodymium isotope composition of deep water exported from the North Atlantic on glacial-interglacial time scales, Geology, 35, 37–40, 2007.
Franzese, A. M., Hemming, S. R., Goldstein, S. L., and Anderson, R. F.: Reduced Agulhas Leakage during the Last Glacial Maximum inferred from an integrated provenance and flux study, Earth Planet. Sc. Lett., 250, 72–88, 2006.
Ganopolski, A., Rahmstorf, S., Petoukhov, V., and Claussen, M.: Simulation of modern and glacial climates with a coupled global model of intermediate complexity, Nature, 391, 351–356, 1998.
Gherardi, J. M., Labeyrie, L., McManus, J. F., Francois, R., Skinner, L. C., and Cortijo, E.: Evidence from the Northeastern Atlantic basin for variability in the rate of the meridional overturning circulation through the last deglaciation, Earth Planet. Sc. Lett., 240, 710–723, 2005.
Goldstein, S. L. and Hemming, S. R.: Long lived Isotopic Tracers in Oceanography, Paleoceanography, and Ice sheet dynamics, in: Treatise on Geochemistry, edited by: Elderfield, H., Elsevier Pergamon press, Amsterdam, chapter 6.17, 2003.
Goosse, H. and Fichefet, T.: Importance of ice-ocean interactions for the global ocean circulation: A model study, J. Geophys. Res.-Oceans, 104, 23 337–23 355, 1999.
Gutjahr, M., Frank, M., Stirling, C. H., Keigwin, L. D., and Halliday, A. N.: Tracing the Nd isotope evolution of North Atlantic deep and intermediate waters in the Western North Atlantic since the Last Glacial Maximum from Blake Ridge sediments, Earth Planet. Sc. Lett., 266, 61–77, 2008.
Henderson, G. M., Heinze, C., Anderson, R. F., and Winguth, A. M. E.: Global distribution of the Th-230 flux to ocean sediments constrained by GCM modelling, Deep-Sea Res. Pt. I, 46, 1861–1893, 1999.
Hourdin, F., Musat, I., Bony, S., Braconnot, P., Codron, F., Dufresne, J. L., Fairhead, L., Filiberti, M. A., Friedlingstein, P., Grandpeix, J. Y., Krinner, G., Levan, P., Li, Z. X., and Lott, F.: The LMDZ4 general circulation model: climate performance and sensitivity to parametrized physics with emphasis on tropical convection, Clim. Dynam., 27, 787–813, 2006.
Jacobsen, S. B. and Wasserburg, G. J.: Sm-Nd isotopic evolution of chondrites, Earth Planet. Sc. Lett., 50, 139–155, 1980.
Jeandel, C.: Concentration and isotopic composition of Nd in the South Atlantic Ocean, Earth Planet. Sc. Lett., 117, 581–591, 1993.
Jeandel, C., Thouron, D., and Fieux, M.: Concentrations and Isotopic compositions of Nd in the Eastern Indian Ocean and Indonesian Straits, Geochim. Cosmochim. Ac., 62, 2597–2607, 1998.
Jeandel, C., Arsouze, T., Lacan, F., Techine, P., and Dutay, J. C.: Isotopic Nd compositions and concentrations of the lithogenic inputs into the ocean: A compilation, with an emphasis on the margins, Chem. Geol., 239, 156–164, 2007.
Keigwin, L. D. and Schlegel, M. A.: Ocean ventilation and sedimentation since the glacial maximum at 3 km in the western North Atlantic, Geochem. Geophy. Geosy., 3, 1034, doi:10.1029/2001GC000283, 2002.
Keigwin, L. D.: Radiocarbon and stable isotope constraints on Last Glacial Maximum and Younger Dryas ventilation in the western North Atlantic, Paleoceanography, 19, PA4012, doi:10.1029/2004PA001029, 2004.
Krinner, G., Viovy, N., de Noblet-Ducoudre, N., Ogee, J., Polcher, J., Friedlingstein, P., Ciais, P., Sitch, S., and Prentice, I. C.: A dynamic global vegetation model for studies of the coupled atmosphere-biosphere system. Global Biogeochem. Cy., 19, GB1015, doi:10.1029/2003GB002199, 2005.
Lacan, F. and Jeandel, C.: Neodymium isotopic composition and rare earth element concentrations in the deep and intermediate Nordic Seas: constraints on the Iceland Scotland Overflow Water signature, Geochem. Geophy. Geosy., 5, Q11006, doi:10.1029/2004GC000742, 2004.
Lacan, F. and Jeandel, C.: Acquisition of the neodymium isotopic composition of the North Atlantic Deep Water, Geochem. Geophy. Geosy., 6, Q12008, doi:10.1029/2005GC000956, 2005a.
Lacan, F. and Jeandel, C.: Neodymium isotopes as a new tool for quantifying exchange fluxes at the continent – ocean interface, Earth Planet. Sc. Lett., 232, 245–257, 2005b.
Lévy, M., Aumont, O., Kremeur, A. S., Memery, L., and Ethé, C.: NEMO reference manual, tracer component: NEMO-TOP, Preliminary version, Note du Pole de modélisation, Institut Pierre-Simon Laplace (IPSL), 28, 2006.
Lynch-Stieglitz, J., Curry, W. B. and Slowey, N.: Weaker Gulf Stream in the Florida straits during the last glacial maximum, Nature, 402, 644–648, 1999.
Lynch-Stieglitz, J., Curry, W. B., Oppo, D. W., Ninneman, U. S., Charles, C. D., and Munson, J.: Meridional overturning circulation in the South Atlantic at the last glacial maximum, Geochem. Geophy. Geosy., 7, Q10N03, doi:10.1029/2005GC001226, 2006.
Lynch-Stieglitz, J., Adkins, J. F., Curry, W. B., Dokken, T., Hall, I. R., Herguera, J. C., Hirschi, J. J. M., Ivanova, E. V., Kissel, C., Marchal, O., Marchitto, T. M., McCave, I. N., McManus, J. F., Mulitza, S., Ninnemann, U., Peeters, F., Yu, E. F., and Zahn, R.: Atlantic meridional overturning circulation during the Last Glacial Maximum, Science, 316, 66–69, 2007.
Madec, G.: NEMO reference manual, ocean dynamics component: NEMO-OPA. Preliminary version, Note du Pole de modélisation, Institut Pierre-Simon Laplace (IPSL), 27, 2006.
Marchal, O., Francois, R., Stocker, F., and Fortunat, J.: Ocean thermohaline circulation and sedimentary $^231$Pa/$^230$Th ratio, Paleoceanography, 15, 625–641, 2000.
Marchitto, T. M. and Broecker, W. S.: Deep water mass geometry in the glacial Atlantic Ocean: A review of constraints from the paleonutrient proxy Cd/Ca, Geochem. Geophy. Geosy., 7, Q12003, doi:10.1029/2006GC001323, 2006.
Marti, O., Braconnot, P., Bellier, J., Benshila, R., Bony, S., Brockmann, P., Cadule, P., Caubel, A., Denvil, S., Dufresne, J.-L., Fairhead, L., Filiberti, M.-A., Foujols, M.-A., Fichefet, T., Friedlingstein, P., Goosse, H., Grandpeix, J.-Y., Hourdin, F., Krinner, G., Lévy, C., Madec, G., Musat, I., de Noblet, N., Polcher, J., and Talandier, C.: The new IPSL climate system model: IPSL-CM4, Note du Pôle de Modélisation 26, 2006.
McManus, J. F., Francois, R., Gherardi, J.-M., Keigwin, L. D., and Brown-Leger, S.: Collapse and rapid resumption of Atlantic meridional circulation linked to deglacial climate changes, Nature, 428, 834–837, 2004.
Oppo, D. and Fairbanks, R. G.: Variability in the Deep and Intermediate Water Circulation of the Atlantic Ocean During the Past 25,000 Years: Northern Hemisphere Modulation of the Southern Ocean, Earth Planet. Sc. Lett., 86, 1–15, 1987.
Oppo, D. and Rosenthal, Y.: Cd/Ca changes in a deep Cape Basin core over the past 730 000 years: Response of circumpolar deepwater variability to northern hemisphere ice sheet melting?, Paleoceanography, 9, 661–676, 1994.
Peltier, W. R.: Global glacial isostasy and the surface of the ice-age earth: The ICE-5G (VM2) Model and GRACE, Annu. Rev. Earth Pl. Sc., 32, 111–149, 2004.
Piepgras, D. J. and Wasserburg, G. J.: Neodymium isotopic variations in seawater, Earth Planet. Sc. Lett., 50, 128–138, 1980.
Piepgras, D. J. and Wasserburg, G. J.: Isotopic composition of neodymium in waters from the Drake Passage, Science, 217, 207–217, 1982.
Piepgras, D. J. and Wasserburg, G. J.: Influence of the Mediterranean outflow on the isotopic composition of neodymium in waters of the North Atlantic, J. Geophys. Res., 88, 5997–6006, 1983.
Piepgras, D. J. and Wasserburg, G. J.: Rare earth element transport in the western North Atlantic inferred from isotopic observations, Geochim. Cosmochim. Ac., 51, 1257–1271, 1987.
Piotrowski, A. M., Goldstein, S. L., Hemming, S. R., and Fairbanks, R. G.: Intensification and variability of ocean thermohaline circulation through the last deglaciation, Earth Planet. Sc. Lett., 225, 205–220, 2004.
Rahmstorf, S.: Ocean circulation and climate during the past 120 000 years, Nature, 419, 207–214, 2002.
Reynolds, B. C., Sherlock, S. C., Kelley, S. P., and Burton, K. W.: Radiogenic isotope records of Quaternary glaciations: Changes in the erosional source and weathering processes, Geology, 32, 861–864, 2004.
Rutberg, R. L., Hemming, S. R., and Goldstein, S. L.: Reduced North Atlantic deep Water flux to the glacial Southern Ocean inferred from neodymium isotope ratios, Nature, 405, 935–938, 2000.
Spivack, A. J. and Wasserburg, G. J.: Neodymium isotopic composition of the Mediterranean outflow and the eastern North Atlantic, Geochim. Cosmochim. Ac.; Vol/Issue: 52:12, Pages: 2767–2773, 1988.
Swingedouw, D., Braconnot, P., Delecluse, P., Guilyardi, E., and Marti, O.: The impact of global freshwater forcing on the thermohaline circulation: adjustment of North Atlantic convection sites in a CGCM, Clim. Dynam., 28, 291–305, 2007.
Tachikawa, K., Athias, V., and Jeandel, C.: Neodymium budget in the ocean and paleoceanographic implications, J. Geophys. Res., 108(C8), 3254, 2003.
Valcke, S.: OASIS3 User Guide (prism_2–5), PRISM Support Initiative Report, 3, 64, 2006.
Van De Flierdt, T., Frank, M., Lee, D. C., Halliday, A. N., Reynolds, B. C., and Hein, J. R.: New constraints on the sources and behavior of neodymium and hafnium in seawater from Pacific Ocean ferromanganese crusts, Geochim. Cosmochim. Ac., 68, 3827–3843, 2004.
van de Flierdt, T., Robinson, L. F., Adkins, J. F., Hemming, S. R., and Goldstein, S. L.: Temporal stability of the neodymium isotope signature of the Holocene to glacial North Atlantic, Paleoceanography, 21, PA4102, doi:10.1029/2006PA001294, 2006.
Vance, D. and Burton, K.: Neodymium isotopes in planktonic foraminifera: A record of the response of continental weathering and ocean circulation rates to climate change, Earth Planet. Sc. Lett., 173, 365–379, 1999.
von Blanckenburg, F.: Perspectives: Paleoceanography – Tracing past ocean circulation?, Science, 286, 1862–1863, 1999.
Yu, E.-F., Francois, R., and Bacon, M.: Similar rates of modern and last-glacial ocean thermohaline circulation inferred from radiochemical data, Nature, 379, 679–680, 1996.