Southwest Atlantic water mass evolution during the last deglaciation
The rise in atmospheric CO2 during Heinrich Stadial 1 (HS1; 14.5–17.5 kyr B.P.) may have been driven by the release of carbon from the abyssal ocean. Model simulations suggest that wind‐driven upwelling in the Southern Ocean can liberate 13C‐depleted carbon from the abyss, causing atmospheric CO2 to...
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Wiley Periodicals, Inc.
2015
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Online Access: | http://hdl.handle.net/2027.42/111970 https://doi.org/10.1002/2014PA002657 |
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ftumdeepblue:oai:deepblue.lib.umich.edu:2027.42/111970 |
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openpolar |
institution |
Open Polar |
collection |
University of Michigan: Deep Blue |
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unknown |
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stable isotopes South Atlantic deglaciation carbon dioxide Atmospheric and Oceanic Sciences Science |
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stable isotopes South Atlantic deglaciation carbon dioxide Atmospheric and Oceanic Sciences Science Lund, D. C. Tessin, A. C. Hoffman, J. L. Schmittner, A. Southwest Atlantic water mass evolution during the last deglaciation |
topic_facet |
stable isotopes South Atlantic deglaciation carbon dioxide Atmospheric and Oceanic Sciences Science |
description |
The rise in atmospheric CO2 during Heinrich Stadial 1 (HS1; 14.5–17.5 kyr B.P.) may have been driven by the release of carbon from the abyssal ocean. Model simulations suggest that wind‐driven upwelling in the Southern Ocean can liberate 13C‐depleted carbon from the abyss, causing atmospheric CO2 to increase and the δ13C of CO2 to decrease. One prediction of the Southern Ocean hypothesis is that water mass tracers in the deep South Atlantic should register a circulation response early in the deglaciation. Here we test this idea using a depth transect of 12 cores from the Brazil Margin. We show that records below 2300 m remained 13C‐depleted until 15 kyr B.P. or later, indicating that the abyssal South Atlantic was an unlikely source of light carbon to the atmosphere during HS1. Benthic δ18O results are consistent with abyssal South Atlantic isolation until 15 kyr B.P., in contrast to shallower sites. The depth dependent timing of the δ18O signal suggests that correcting δ18O for ice volume is problematic on glacial terminations. New data from 2700 to 3000 m show that the deep SW Atlantic was isotopically distinct from the abyss during HS1. As a result, we find that mid‐depth δ13C minima were most likely driven by an abrupt drop in δ13C of northern component water. Low δ13C at the Brazil Margin also coincided with an ~80‰ decrease in Δ14C. Our results are consistent with a weakening of the Atlantic meridional overturning circulation and point toward a northern hemisphere trigger for the initial rise in atmospheric CO2 during HS1.Key PointsDeep SW Atlantic was unlikely source of light carbon to atmosphere during HS1Mid‐depth isotopic anomalies due to change in northern component waterNorthern component water had robust influence in South Atlantic during HS1 Peer Reviewed http://deepblue.lib.umich.edu/bitstream/2027.42/111970/1/palo20190.pdf |
format |
Article in Journal/Newspaper |
author |
Lund, D. C. Tessin, A. C. Hoffman, J. L. Schmittner, A. |
author_facet |
Lund, D. C. Tessin, A. C. Hoffman, J. L. Schmittner, A. |
author_sort |
Lund, D. C. |
title |
Southwest Atlantic water mass evolution during the last deglaciation |
title_short |
Southwest Atlantic water mass evolution during the last deglaciation |
title_full |
Southwest Atlantic water mass evolution during the last deglaciation |
title_fullStr |
Southwest Atlantic water mass evolution during the last deglaciation |
title_full_unstemmed |
Southwest Atlantic water mass evolution during the last deglaciation |
title_sort |
southwest atlantic water mass evolution during the last deglaciation |
publisher |
Wiley Periodicals, Inc. |
publishDate |
2015 |
url |
http://hdl.handle.net/2027.42/111970 https://doi.org/10.1002/2014PA002657 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
Lund, D. C.; Tessin, A. C.; Hoffman, J. L.; Schmittner, A. (2015). "Southwest Atlantic water mass evolution during the last deglaciation." Paleoceanography 30(5): 477-494. 0883-8305 1944-9186 http://hdl.handle.net/2027.42/111970 doi:10.1002/2014PA002657 Paleoceanography Sigman, D. M., and E. A. Boyle ( 2000 ), Glacial/interglacial variations in atmospheric carbon dioxide, Nature, 407 ( 6806 ), 859 – 869. Schlitzer, R. ( 2000 ), Ellectronic atlas of WOCE hydrographic and tracer data now available, Eos Trans. AGU, 81 ( 5 ), 45 – 45, doi:10.1029/00EO00028. Schmitt, J., et al. ( 2012 ), Carbon isotope constraints on the deglacial CO 2 rise from ice cores, Science, 336 ( 6082 ), 711 – 714. Schmittner, A., and D. C. Lund ( 2015 ), Early deglacial Atlantic overturning decline and its role in atmospheric CO2 rise inferred from carbon isotopes (δ13C), Clim. Past, 1, 135 – 152, doi:10.5194/cp-11-135-2015. Shakun, J. D., P. U. Clark, F. He, S. A. Marcott, A. C. Mix, Z. Y. Liu, B. Otto‐Bliesner, A. Schmittner, and E. Bard ( 2012 ), Global warming preceded by increasing carbon dioxide concentrations during the last deglaciation, Nature, 484 ( 7392 ), 49 – 54. Slowey, N. C., and W. B. Curry ( 1995 ), Glacial‐interglacial differences in circulation and carbon cycling within the upper western North‐Atlantic, Paleoceanography, 10, 715 – 732, doi:10.1029/95PA01166. Sortor, R. N., and D. C. Lund ( 2011 ), No evidence for a deglacial intermediate water Delta C‐14 anomaly in the SW Atlantic, Earth Planet. Sci. Lett., 310 ( 1–2 ), 65 – 72. Southon, J., A. L. Noronha, H. Cheng, R. L. Edwards, and Y. J. Wang ( 2012 ), A high‐resolution record of atmospheric C‐14 based on Hulu Cave speleothem H82, Quat. Sci. Rev., 33, 32 – 41. Spero, H. J., and D. W. Lea ( 2002 ), The cause of carbon isotope minimum events on glacial terminations, Science, 296 ( 5567 ), 522 – 525. Stern, J. V., and L. E. Lisiecki ( 2013 ), North Atlantic circulation and reservoir age changes over the past 41,000 years, Geophys. Res. Lett., 40, 3693 – 3697, doi:10.1002/grl.50679. Stuiver, M., and H. G. Ostlund ( 1980 ), Geosecs Atlantic radiocarbon, Radiocarbon, 22, 1 – 24. Tessin, A. C., and D. C. Lund ( 2013 ), Isotopically depleted carbon in the mid‐depth South Atlantic during the last deglaciation, Paleoceanography, 28, 296 – 306, doi:10.1002/palo.20026. Thompson, W. G., and S. L. Goldstein ( 2006 ), A radiometric calibration of the SPECMAP timescale, Quat. Sci. Rev., 25 ( 23–24 ), 3207 – 3215. Thornalley, D. J. R., I. N. McCave, and H. Elderfield ( 2010 ), Freshwater input and abrupt deglacial climate change in the North Atlantic, Paleoceanography, 25, PA1201, doi:10.1029/2009PA001772. Thornalley, D. J. R., S. Barker, W. S. Broecker, H. Elderfield, and I. N. McCave ( 2011 ), The deglacial evolution of North Atlantic deep convection, Science, 331, 202 – 205. Tschumi, T., F. Joos, M. Gehlen, and C. Heinze ( 2011 ), Deep ocean ventilation, carbon isotopes, marine sedimentation and the deglacial CO 2 rise, Clim. Past, 7 ( 3 ), 771 – 800. Veres, D., et al. ( 2012 ), The Antarctic ice core chronology (AICC2012): An optimized multi‐parameter and multi‐site dating approach for the last 120 thousand years, Clim. Past Discuss., 8, 6011 – 6049. Waelbroeck, C., L. C. Skinner, L. Labeyrie, J. C. Duplessy, E. Michel, N. V. Riveiros, J. M. Gherardi, and F. Dewilde ( 2011 ), The timing of deglacial circulation changes in the Atlantic, Paleoceanography, 26, PA3213, doi:10.1029/2010PA002007. Yu, J. M., W. S. Broecker, H. Elderfield, Z. D. Jin, J. McManus, and F. Zhang ( 2010 ), Loss of carbon from the deep sea since the Last Glacial Maximum, Science, 330 ( 6007 ), 1084 – 1087. Zahn, R., and A. Stuber ( 2002 ), Suborbital intermediate water variability inferred from paired benthic foraminiferal Cd/Ca and delta C‐13 in the tropical West Atlantic and linking with North Atlantic climates, Earth Planet. Sci. Lett., 200 ( 1–2 ), 191 – 205. Zahn, R., J. Schonfeld, H. R. Kudrass, M. H. Park, H. Erlenkeuser, and P. Grootes ( 1997 ), Thermohaline instability in the North Atlantic during meltwater events: Stable isotope and ice‐rafted detritus records from core SO75‐26KL, Portuguese margin, Paleoceanography, 12, 696 – 710, doi:10.1029/97PA00581. Adkins, J. F., K. McIntyre, and D. P. Schrag ( 2002 ), The salinity, temperature, and delta O‐18 of the glacial deep ocean, Science, 298 ( 5599 ), 1769 – 1773. Anderson, R. F., S. Ali, L. I. Bradtmiller, S. H. H. Nielsen, M. Q. Fleisher, B. E. Anderson, and L. H. Burckle ( 2009 ), Wind‐driven upwelling in the Southern Ocean and the deglacial rise in atmospheric CO2, Science, 323 ( 5920 ), 1443 – 1448. Angulo, R. J., M. C. de Souza, P. J. Reimer, and S. K. Sasaoka ( 2005 ), Reservoir effect of the southern and southeastern Brazilian coast, Radiocarbon, 47 ( 1 ), 67 – 73. Broecker, W. S. ( 1982 ), Ocean chemistry during glacial time, Geochim. Cosmochim. Acta, 46 ( 10 ), 1689 – 1705. Burke, A., and L. F. Robinson ( 2012 ), The Southern Ocean's role in carbon exchange during the last deglaciation, Science, 335 ( 6068 ), 557 – 561. Clark, P. U., A. S. Dyke, J. D. Shakun, A. E. Carlson, J. Clark, B. Wohlfarth, J. X. Mitrovica, S. W. Hostetler, and A. M. McCabe ( 2009 ), The Last Glacial Maximum, Science, 325 ( 5941 ), 710 – 714. Cleroux, C., P. Demenocal, and T. Guilderson ( 2011 ), Deglacial radiocarbon history of tropical Atlantic thermocline waters: Absence of CO 2 reservoir purging signal, Quat. Sci. Rev., 30 ( 15–16 ), 1875 – 1882. Curry, W. B., and D. W. Oppo ( 2005 ), Glacial water mass geometry and the distribution of delta C‐13 of Sigma CO 2 in the western Atlantic Ocean, Paleoceanography, 20, PA1017, doi:10.1029/2004PA001021. Curry, W. B., J. C. Duplessy, L. D. Labeyrie, and N. J. Shackleton ( 1988 ), Changes in the distribution of d13C of deep water CO 2 between the last glaciation and Holocene, Paleoceanography, 3, 317 – 341, doi:10.1029/PA003i003p00317. Cutler, K. B., R. L. Edwards, F. W. Taylor, H. Cheng, J. Adkins, C. D. Gallup, P. M. Cutler, G. S. Burr, and A. L. Bloom ( 2003 ), Rapid sea‐level fall and deep‐ocean temperature change since the last interglacial period, Earth Planet. Sci. Lett., 206 ( 3–4 ), 253 – 271. Dokken, T. M., and E. Jansen ( 1999 ), Rapid changes in the mechanism of ocean convection during the last glacial period, Nature, 401 ( 6752 ), 458 – 461. Duplessy, J. C., N. J. Shackleton, R. G. Fairbanks, L. Labeyrie, D. Oppo, and N. Kallel ( 1988 ), Deep water source variations during the last climatic cycle and their impact on the global deep water circulation, Paleoceanography, 3, 343 – 360. Elderfield, H., J. Yu, P. Anand, T. Kiefer, and B. Nyland ( 2006 ), Calibrations for benthic foraminiferal Mg/Ca paleothermometry and the carbonate ion hypothesis, Earth Planet. Sci. Lett., 250 ( 3–4 ), 633 – 649. Gebhardt, H., M. Sarnthein, P. M. Grootes, T. Kiefer, H. Kuehn, F. Schmieder, and U. Rohl ( 2008 ), Paleonutrient and productivity records from the subarctic North Pacific for Pleistocene glacial terminations I to V, Paleoceanography, 23, PA4212, doi:10.1029/2007PA001513. Gherardi, J. M., L. Labeyrie, S. Nave, R. Francois, J. F. McManus, and E. Cortijo ( 2009 ), Glacial‐interglacial circulation changes inferred from Pa‐231/Th‐230 sedimentary record in the North Atlantic region, Paleoceanography, 24, PA2204, doi:10.1029/2008PA001696. Herguera, J. C., T. Herbert, M. Kashgarian, and C. Charles ( 2010 ), Intermediate and deep water mass distribution in the Pacific during the Last Glacial Maximum inferred from oxygen and carbon stable isotopes, Quat. Sci. Rev., 29 ( 9–10 ), 1228 – 1245. Hoffman, J. L., and D. C. Lund ( 2012 ), Refining the stable isotope budget for Antarctic Bottom Water: New foraminiferal data from the abyssal southwest Atlantic, Paleoceanography, 27, PA1213, doi:10.1029/2011PA002216. Kallel, N., L. D. Labeyrie, A. Juilletleclerc, and J. C. Duplessy ( 1988 ), A deep hydrological front between intermediate and deep‐water masses in the glacial Indian Ocean, Nature, 333 ( 6174 ), 651 – 655. Keigwin, L. D., and E. A. Boyle ( 2008 ), Did North Atlantic overturning halt 17,000 years ago?, Paleoceanography, 23, PA1101, doi:10.1029/2007PA001500. Key, R. M., A. Kozyr, C. L. Sabine, K. Lee, R. Wanninkhof, J. L. Bullister, R. A. Feely, F. J. Millero, C. Mordy, and T. H. Peng ( 2004 ), A global ocean carbon climatology: Results from Global Data Analysis Project (GLODAP), Global Biogeochem. Cycles, 18, GB4031, doi:10.1029/2004GB002247. Lippold, J., J. Grutzner, D. Winter, Y. Lahaye, A. Mangini, and M. Christl ( 2009 ), Does sedimentary Pa‐231/Th‐230 from the Bermuda Rise monitor past Atlantic Meridional Overturning Circulation?, Geophys. Res. Lett., 36, L12601, doi:10.1029/2009GL038068. Lund, D. C., J. F. Adkins, and R. Ferrari ( 2011a ), Abyssal Atlantic circulation during the Last Glacial Maximum: Constraining the ratio between transport and vertical mixing, Paleoceanography, 26, PA1213, doi:10.1029/2010PA001938. Lund, D. C., A. C. Mix, and J. Southon ( 2011b ), Increased ventilation age of the deep northeast Pacific Ocean during the last deglaciation, Nat. Geosci., 4, 771 – 774. |
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ftumdeepblue:oai:deepblue.lib.umich.edu:2027.42/111970 2023-08-20T04:09:56+02:00 Southwest Atlantic water mass evolution during the last deglaciation Lund, D. C. Tessin, A. C. Hoffman, J. L. Schmittner, A. 2015-05 application/pdf http://hdl.handle.net/2027.42/111970 https://doi.org/10.1002/2014PA002657 unknown Wiley Periodicals, Inc. Lund, D. C.; Tessin, A. C.; Hoffman, J. L.; Schmittner, A. (2015). "Southwest Atlantic water mass evolution during the last deglaciation." Paleoceanography 30(5): 477-494. 0883-8305 1944-9186 http://hdl.handle.net/2027.42/111970 doi:10.1002/2014PA002657 Paleoceanography Sigman, D. M., and E. A. Boyle ( 2000 ), Glacial/interglacial variations in atmospheric carbon dioxide, Nature, 407 ( 6806 ), 859 – 869. Schlitzer, R. ( 2000 ), Ellectronic atlas of WOCE hydrographic and tracer data now available, Eos Trans. AGU, 81 ( 5 ), 45 – 45, doi:10.1029/00EO00028. Schmitt, J., et al. ( 2012 ), Carbon isotope constraints on the deglacial CO 2 rise from ice cores, Science, 336 ( 6082 ), 711 – 714. Schmittner, A., and D. C. Lund ( 2015 ), Early deglacial Atlantic overturning decline and its role in atmospheric CO2 rise inferred from carbon isotopes (δ13C), Clim. Past, 1, 135 – 152, doi:10.5194/cp-11-135-2015. Shakun, J. D., P. U. Clark, F. He, S. A. Marcott, A. C. Mix, Z. Y. Liu, B. Otto‐Bliesner, A. Schmittner, and E. Bard ( 2012 ), Global warming preceded by increasing carbon dioxide concentrations during the last deglaciation, Nature, 484 ( 7392 ), 49 – 54. Slowey, N. C., and W. B. Curry ( 1995 ), Glacial‐interglacial differences in circulation and carbon cycling within the upper western North‐Atlantic, Paleoceanography, 10, 715 – 732, doi:10.1029/95PA01166. Sortor, R. N., and D. C. Lund ( 2011 ), No evidence for a deglacial intermediate water Delta C‐14 anomaly in the SW Atlantic, Earth Planet. Sci. Lett., 310 ( 1–2 ), 65 – 72. Southon, J., A. L. Noronha, H. Cheng, R. L. Edwards, and Y. J. Wang ( 2012 ), A high‐resolution record of atmospheric C‐14 based on Hulu Cave speleothem H82, Quat. Sci. Rev., 33, 32 – 41. Spero, H. J., and D. W. Lea ( 2002 ), The cause of carbon isotope minimum events on glacial terminations, Science, 296 ( 5567 ), 522 – 525. Stern, J. V., and L. E. Lisiecki ( 2013 ), North Atlantic circulation and reservoir age changes over the past 41,000 years, Geophys. Res. Lett., 40, 3693 – 3697, doi:10.1002/grl.50679. Stuiver, M., and H. G. Ostlund ( 1980 ), Geosecs Atlantic radiocarbon, Radiocarbon, 22, 1 – 24. Tessin, A. C., and D. C. Lund ( 2013 ), Isotopically depleted carbon in the mid‐depth South Atlantic during the last deglaciation, Paleoceanography, 28, 296 – 306, doi:10.1002/palo.20026. Thompson, W. G., and S. L. Goldstein ( 2006 ), A radiometric calibration of the SPECMAP timescale, Quat. Sci. Rev., 25 ( 23–24 ), 3207 – 3215. Thornalley, D. J. R., I. N. McCave, and H. Elderfield ( 2010 ), Freshwater input and abrupt deglacial climate change in the North Atlantic, Paleoceanography, 25, PA1201, doi:10.1029/2009PA001772. Thornalley, D. J. R., S. Barker, W. S. Broecker, H. Elderfield, and I. N. McCave ( 2011 ), The deglacial evolution of North Atlantic deep convection, Science, 331, 202 – 205. Tschumi, T., F. Joos, M. Gehlen, and C. Heinze ( 2011 ), Deep ocean ventilation, carbon isotopes, marine sedimentation and the deglacial CO 2 rise, Clim. Past, 7 ( 3 ), 771 – 800. Veres, D., et al. ( 2012 ), The Antarctic ice core chronology (AICC2012): An optimized multi‐parameter and multi‐site dating approach for the last 120 thousand years, Clim. Past Discuss., 8, 6011 – 6049. Waelbroeck, C., L. C. Skinner, L. Labeyrie, J. C. Duplessy, E. Michel, N. V. Riveiros, J. M. Gherardi, and F. Dewilde ( 2011 ), The timing of deglacial circulation changes in the Atlantic, Paleoceanography, 26, PA3213, doi:10.1029/2010PA002007. Yu, J. M., W. S. Broecker, H. Elderfield, Z. D. Jin, J. McManus, and F. Zhang ( 2010 ), Loss of carbon from the deep sea since the Last Glacial Maximum, Science, 330 ( 6007 ), 1084 – 1087. Zahn, R., and A. Stuber ( 2002 ), Suborbital intermediate water variability inferred from paired benthic foraminiferal Cd/Ca and delta C‐13 in the tropical West Atlantic and linking with North Atlantic climates, Earth Planet. Sci. Lett., 200 ( 1–2 ), 191 – 205. Zahn, R., J. Schonfeld, H. R. Kudrass, M. H. Park, H. Erlenkeuser, and P. Grootes ( 1997 ), Thermohaline instability in the North Atlantic during meltwater events: Stable isotope and ice‐rafted detritus records from core SO75‐26KL, Portuguese margin, Paleoceanography, 12, 696 – 710, doi:10.1029/97PA00581. Adkins, J. F., K. McIntyre, and D. P. Schrag ( 2002 ), The salinity, temperature, and delta O‐18 of the glacial deep ocean, Science, 298 ( 5599 ), 1769 – 1773. Anderson, R. F., S. Ali, L. I. Bradtmiller, S. H. H. Nielsen, M. Q. Fleisher, B. E. Anderson, and L. H. Burckle ( 2009 ), Wind‐driven upwelling in the Southern Ocean and the deglacial rise in atmospheric CO2, Science, 323 ( 5920 ), 1443 – 1448. Angulo, R. J., M. C. de Souza, P. J. Reimer, and S. K. Sasaoka ( 2005 ), Reservoir effect of the southern and southeastern Brazilian coast, Radiocarbon, 47 ( 1 ), 67 – 73. Broecker, W. S. ( 1982 ), Ocean chemistry during glacial time, Geochim. Cosmochim. Acta, 46 ( 10 ), 1689 – 1705. Burke, A., and L. F. Robinson ( 2012 ), The Southern Ocean's role in carbon exchange during the last deglaciation, Science, 335 ( 6068 ), 557 – 561. Clark, P. U., A. S. Dyke, J. D. Shakun, A. E. Carlson, J. Clark, B. Wohlfarth, J. X. Mitrovica, S. W. Hostetler, and A. M. McCabe ( 2009 ), The Last Glacial Maximum, Science, 325 ( 5941 ), 710 – 714. Cleroux, C., P. Demenocal, and T. Guilderson ( 2011 ), Deglacial radiocarbon history of tropical Atlantic thermocline waters: Absence of CO 2 reservoir purging signal, Quat. Sci. Rev., 30 ( 15–16 ), 1875 – 1882. Curry, W. B., and D. W. Oppo ( 2005 ), Glacial water mass geometry and the distribution of delta C‐13 of Sigma CO 2 in the western Atlantic Ocean, Paleoceanography, 20, PA1017, doi:10.1029/2004PA001021. Curry, W. B., J. C. Duplessy, L. D. Labeyrie, and N. J. Shackleton ( 1988 ), Changes in the distribution of d13C of deep water CO 2 between the last glaciation and Holocene, Paleoceanography, 3, 317 – 341, doi:10.1029/PA003i003p00317. Cutler, K. B., R. L. Edwards, F. W. Taylor, H. Cheng, J. Adkins, C. D. Gallup, P. M. Cutler, G. S. Burr, and A. L. Bloom ( 2003 ), Rapid sea‐level fall and deep‐ocean temperature change since the last interglacial period, Earth Planet. Sci. Lett., 206 ( 3–4 ), 253 – 271. Dokken, T. M., and E. Jansen ( 1999 ), Rapid changes in the mechanism of ocean convection during the last glacial period, Nature, 401 ( 6752 ), 458 – 461. Duplessy, J. C., N. J. Shackleton, R. G. Fairbanks, L. Labeyrie, D. Oppo, and N. Kallel ( 1988 ), Deep water source variations during the last climatic cycle and their impact on the global deep water circulation, Paleoceanography, 3, 343 – 360. Elderfield, H., J. Yu, P. Anand, T. Kiefer, and B. Nyland ( 2006 ), Calibrations for benthic foraminiferal Mg/Ca paleothermometry and the carbonate ion hypothesis, Earth Planet. Sci. Lett., 250 ( 3–4 ), 633 – 649. Gebhardt, H., M. Sarnthein, P. M. Grootes, T. Kiefer, H. Kuehn, F. Schmieder, and U. Rohl ( 2008 ), Paleonutrient and productivity records from the subarctic North Pacific for Pleistocene glacial terminations I to V, Paleoceanography, 23, PA4212, doi:10.1029/2007PA001513. Gherardi, J. M., L. Labeyrie, S. Nave, R. Francois, J. F. McManus, and E. Cortijo ( 2009 ), Glacial‐interglacial circulation changes inferred from Pa‐231/Th‐230 sedimentary record in the North Atlantic region, Paleoceanography, 24, PA2204, doi:10.1029/2008PA001696. Herguera, J. C., T. Herbert, M. Kashgarian, and C. Charles ( 2010 ), Intermediate and deep water mass distribution in the Pacific during the Last Glacial Maximum inferred from oxygen and carbon stable isotopes, Quat. Sci. Rev., 29 ( 9–10 ), 1228 – 1245. Hoffman, J. L., and D. C. Lund ( 2012 ), Refining the stable isotope budget for Antarctic Bottom Water: New foraminiferal data from the abyssal southwest Atlantic, Paleoceanography, 27, PA1213, doi:10.1029/2011PA002216. Kallel, N., L. D. Labeyrie, A. Juilletleclerc, and J. C. Duplessy ( 1988 ), A deep hydrological front between intermediate and deep‐water masses in the glacial Indian Ocean, Nature, 333 ( 6174 ), 651 – 655. Keigwin, L. D., and E. A. Boyle ( 2008 ), Did North Atlantic overturning halt 17,000 years ago?, Paleoceanography, 23, PA1101, doi:10.1029/2007PA001500. Key, R. M., A. Kozyr, C. L. Sabine, K. Lee, R. Wanninkhof, J. L. Bullister, R. A. Feely, F. J. Millero, C. Mordy, and T. H. Peng ( 2004 ), A global ocean carbon climatology: Results from Global Data Analysis Project (GLODAP), Global Biogeochem. Cycles, 18, GB4031, doi:10.1029/2004GB002247. Lippold, J., J. Grutzner, D. Winter, Y. Lahaye, A. Mangini, and M. Christl ( 2009 ), Does sedimentary Pa‐231/Th‐230 from the Bermuda Rise monitor past Atlantic Meridional Overturning Circulation?, Geophys. Res. Lett., 36, L12601, doi:10.1029/2009GL038068. Lund, D. C., J. F. Adkins, and R. Ferrari ( 2011a ), Abyssal Atlantic circulation during the Last Glacial Maximum: Constraining the ratio between transport and vertical mixing, Paleoceanography, 26, PA1213, doi:10.1029/2010PA001938. Lund, D. C., A. C. Mix, and J. Southon ( 2011b ), Increased ventilation age of the deep northeast Pacific Ocean during the last deglaciation, Nat. Geosci., 4, 771 – 774. IndexNoFollow stable isotopes South Atlantic deglaciation carbon dioxide Atmospheric and Oceanic Sciences Science Article 2015 ftumdeepblue https://doi.org/10.1002/2014PA00265710.1029/00EO0002810.5194/cp-11-135-201510.1029/95PA0116610.1002/grl.5067910.1002/palo.2002610.1029/2009PA00177210.1029/2010PA00200710.1029/97PA0058110.1029/2004PA00102110.1029/PA003i003p0031710.1029/2007PA00151310.1029/ 2023-07-31T20:52:55Z The rise in atmospheric CO2 during Heinrich Stadial 1 (HS1; 14.5–17.5 kyr B.P.) may have been driven by the release of carbon from the abyssal ocean. Model simulations suggest that wind‐driven upwelling in the Southern Ocean can liberate 13C‐depleted carbon from the abyss, causing atmospheric CO2 to increase and the δ13C of CO2 to decrease. One prediction of the Southern Ocean hypothesis is that water mass tracers in the deep South Atlantic should register a circulation response early in the deglaciation. Here we test this idea using a depth transect of 12 cores from the Brazil Margin. We show that records below 2300 m remained 13C‐depleted until 15 kyr B.P. or later, indicating that the abyssal South Atlantic was an unlikely source of light carbon to the atmosphere during HS1. Benthic δ18O results are consistent with abyssal South Atlantic isolation until 15 kyr B.P., in contrast to shallower sites. The depth dependent timing of the δ18O signal suggests that correcting δ18O for ice volume is problematic on glacial terminations. New data from 2700 to 3000 m show that the deep SW Atlantic was isotopically distinct from the abyss during HS1. As a result, we find that mid‐depth δ13C minima were most likely driven by an abrupt drop in δ13C of northern component water. Low δ13C at the Brazil Margin also coincided with an ~80‰ decrease in Δ14C. Our results are consistent with a weakening of the Atlantic meridional overturning circulation and point toward a northern hemisphere trigger for the initial rise in atmospheric CO2 during HS1.Key PointsDeep SW Atlantic was unlikely source of light carbon to atmosphere during HS1Mid‐depth isotopic anomalies due to change in northern component waterNorthern component water had robust influence in South Atlantic during HS1 Peer Reviewed http://deepblue.lib.umich.edu/bitstream/2027.42/111970/1/palo20190.pdf Article in Journal/Newspaper Southern Ocean University of Michigan: Deep Blue Southern Ocean Paleoceanography 30 5 477 494 |