• Blockley, S. P. E., and Coauthors, 2012: Synchronisation of palaeoenvironmental records over the last 60,000 years, and an extended INTIMATE event stratigraphy to 48,000 b2k. Quat. Sci. Rev.,36, 2–10, doi:10.1016/j.quascirev.2011.09.017.

  • Broccoli, A. J., , K. A. Dahl, , and R. J. Stouffer, 2006: Response of the ITCZ to Northern Hemisphere cooling. Geophys. Res. Lett., 33, L01702, doi:10.1029/2005GL024546.

    • Search Google Scholar
    • Export Citation
  • Broecker, W. S., 2006: Abrupt climate change revisited. Global Planet. Change,54 (3–4), 211–215, doi:10.1016/j.gloplacha.2006.06.019.

  • Cess, R. D., and Coauthors, 1996: Cloud feedback in atmospheric general circulation models: An update. J. Geophys. Res., 101 (D8), 12 79112 794.

    • Search Google Scholar
    • Export Citation
  • Chiang, J. C. H., , and C. M. Bitz, 2005: Influence of high latitude ice cover on the marine intertropical convergence zone. Climate Dyn., 25, 477496.

    • Search Google Scholar
    • Export Citation
  • Chiang, J. C. H., , and K. M. Cuffey, cited 2008: A simpler interpretation for high-resolution Greenland ice core data. [Available online at http://www.sciencemag.org/content/321/5889/680/reply.]

  • Chiang, J. C. H., , and A. R. Friedman, 2012: Extratropical cooling, interhemispheric thermal gradients, and tropical climate change. Annu. Rev. Earth Planet. Sci., 40, 383412, doi:10.1146/annurev-earth-042711-105545.

    • Search Google Scholar
    • Export Citation
  • Collins, W. D., and Coauthors, 2004: Description of the NCAR Community Atmosphere Model (CAM3). National Center for Atmospheric Research Tech. Note NCAR/TN-464+STR, 226 pp.

  • Collins, W. D., and Coauthors, 2006: The formulation and atmospheric simulation of the Community Atmosphere Model version 3 (CAM3). J. Climate, 19, 21442161.

    • Search Google Scholar
    • Export Citation
  • Cvijanovic, I., , and J. C. H. Chiang, 2013: Global energy budget changes to high latitude North Atlantic cooling and the tropical ITCZ response. Climate Dyn., 40, 14351452, doi:10.1007/s00382-012-1482-1.

    • Search Google Scholar
    • Export Citation
  • Dubois, N., , M. Kienast, , S. S. Kienast, , C. Normandeau, , S. E. Calvert, , T. D. Herbert, , and A. C. Mix, 2011: Millennial scale variations in hydrography and biogeochemistry in the eastern equatorial Pacific over the last 100 kyr. Quat. Sci. Rev., 30, 210223.

    • Search Google Scholar
    • Export Citation
  • Frierson, D. M. W., , and Y.-T. Hwang, 2012: Extratropical influence on ITCZ shifts in slab ocean simulations of global warming. J. Climate, 25, 720733.

    • Search Google Scholar
    • Export Citation
  • Hansen, J., , A. Lacis, , D. Rind, , G. Russell, , P. Stone, , I. Fung, , R. Ruedy, , and J. Lerner, 1984: Climate sensitivity: Analysis of feedback mechanisms. Climate Processes and Climate Sensitivity, Geophys. Monogr., Vol. 29, Amer. Geophys. Union, 130–163.

  • Holden, P. B., , N. R. Edwards, , E. W. Wolff, , N. J. Lang, , J. S. Singarayer, , P. J. Valdes, , and T. F. Stocker, 2010: Interhemispheric coupling, the West Antarctic Ice Sheet and warm Antarctic interglacials. Climate Past, 6, 431444.

    • Search Google Scholar
    • Export Citation
  • Hou, A. Y., , and R. S. Lindzen, 1992: The influence of concentrated heating on the Hadley circulation. J. Atmos. Sci.,49, 1233–1241.

  • Hwang, Y.-T., , and D. M. W. Frierson, 2010: Increasing atmospheric poleward energy transport with global warming. Geophys. Res. Lett., 37, L24807, doi:10.1029/2010GL045440.

    • Search Google Scholar
    • Export Citation
  • Jouzel, J., and Coauthors, 2007: Orbital and millennial Antarctic climate variability over the past 800,000 years. Science, 317, 793796, doi:10.1126/science.1141038.

    • Search Google Scholar
    • Export Citation
  • Kang, S. M., , and I. M. Held, 2012: Tropical precipitation, SSTs and the surface energy budget: A zonally symmetric perspective. Climate Dyn., 38, 19171924, doi:10.1007/s00382-011-1048-7.

    • Search Google Scholar
    • Export Citation
  • Kang, S. M., , I. M. Held, , D. M. W. Frierson, , and M. Zhao, 2008: The response of the ITCZ to extratropical thermal forcing: Idealized slab-ocean experiments with a GCM. J. Climate, 21, 35213532.

    • Search Google Scholar
    • Export Citation
  • Kang, S. M., , D. M. W. Frierson, , and I. M. Held, 2009: The tropical response to extratropical thermal forcing in an idealized GCM: The importance of radiative feedbacks and convective parameterization. J. Atmos. Sci., 66, 28122827.

    • Search Google Scholar
    • Export Citation
  • Kanner, L. C., , S. J. Burns, , H. Cheng, , and R. L. Edwards, 2012: High-latitude forcing of the South American summer monsoon. Science, 335, 570573, doi:10.1126/science.1213397.

    • Search Google Scholar
    • Export Citation
  • Knorr, G., , and G. Lohmann, 2003: Southern Ocean origin for the resumption of Atlantic thermohaline circulation during deglaciation. Nature,424, 532–536.

  • Koutavas, A., , and J. P. Sachs, 2008: Northern timing of deglaciation in the eastern equatorial Pacific from alkenone paleothermometry. Paleoceanography, 23, PA4205, doi:10.1029/2008PA001593.

    • Search Google Scholar
    • Export Citation
  • Langen, P. L., , R. G. Graversen, , and T. Mauritsen, 2012: Separation of contributions from radiative feedbacks to polar amplification on an aquaplanet. J. Climate, 25, 30103024.

    • Search Google Scholar
    • Export Citation
  • Lea, D. W., , D. K. Pak, , L. C. Peterson, , and K. A. Hughen, 2003: Synchronicity of tropical and high-latitude Atlantic temperatures over the last glacial termination. Science, 301, 13611364.

    • Search Google Scholar
    • Export Citation
  • Lee, S., , and H. K. Kim, 2003: The dynamical relationship between subtropical and eddy-driven jets. J. Atmos. Sci., 60, 14901503.

  • Lee, S.-Y., , J. C. H. Chiang, , K. Matsumoto, , and K. S. Tokos, 2011: Southern Ocean wind response to North Atlantic cooling and the rise in atmospheric CO2: Modeling perspective and paleoceanographic implications. Paleoceanography, 26, PA1214, doi:10.1029/2010PA002004.

    • Search Google Scholar
    • Export Citation
  • Lindzen, R. S., , and S. Nigam, 1987: On the role of sea-surface temperature gradients in forcing low level winds and convergence in the tropics. J. Atmos. Sci., 44, 24402458.

    • Search Google Scholar
    • Export Citation
  • Lindzen, R. S., , and A. Y. Hou, 1988: Hadley circulations for zonally averaged heating centered off the equator. J. Atmos. Sci., 45, 24162427.

    • Search Google Scholar
    • Export Citation
  • Mahajan, S., , R. Saravanan, , and P. Chang, 2011: The role of the wind–evaporation–sea surface temperature (WES) feedback as a thermodynamic pathway for the equatorward propagation of high-latitude sea ice-induced cold anomalies. J. Climate, 24, 13501361.

    • Search Google Scholar
    • Export Citation
  • Mashiotta, T. A., , D. W. Lea, , and H. J. Spero, 1999: Glacial–interglacial changes in Subantarctic sea surface temperature and δ18O-water using foraminiferal Mg. Earth Planet. Sci. Lett., 170, 417432.

    • Search Google Scholar
    • Export Citation
  • McManus, J. F., , R. F. Anderson, , W. S. Broecker, , M. Q. Fleisher, , and S. M. Higgins, 1998: Radiometrically determined fluxes in the sub-polar North Atlantic during the last 140,000 years. Earth Planet. Sci. Lett., 135, 2943.

    • Search Google Scholar
    • Export Citation
  • McManus, J. F., , R. Francois, , J. M. Gherardi, , L. D. Keigwin, , and S. Brown-Leger, 2004: Collapse and rapid resumption of Atlantic meridional circulation linked to deglacial climate changes. Nature, 428, 834837.

    • Search Google Scholar
    • Export Citation
  • Montoya, M., , and A. Levermann, 2008: Surface wind-stress threshold for glacial Atlantic overturning. Geophys. Res. Lett., 35, L03608, doi:10.1029/2007GL032560.

    • Search Google Scholar
    • Export Citation
  • Okumura, Y., , S.-P. Xie, , A. Numaguti, , and Y. Tanimoto, 2001: Tropical Atlantic air-sea interaction and its influence on the NAO. Geophys. Res. Lett., 28, 15071510.

    • Search Google Scholar
    • Export Citation
  • Otto-Bliesner, B. L., , and E. C. Brady, 2010: The sensitivity of the climate response to the magnitude and location of freshwater forcing: Last Glacial Maximum experiments. Quat. Sci. Rev., 29, 5673.

    • Search Google Scholar
    • Export Citation
  • Pedro, J. B., , T. D. van Ommen, , S. O. Rasmussen, , V. I. Morgan, , J. Chappellaz, , A. D. Moy, , V. Masson-Delmotte, , and M. Delmotte, 2011: The last deglaciation: Timing the bipolar seesaw. Climate Past, 7, 671683, doi:10.5194/cp-7-671-2011.

    • Search Google Scholar
    • Export Citation
  • Peterson, L. C., , G. H. Haug, , K. A. Hughen, , and U. Röhl, 2000: Rapid changes in the hydrologic cycle of the tropical Atlantic during the last glacial. Science, 290, 19471951, doi:10.1126/science.290.5498.1947.

    • Search Google Scholar
    • Export Citation
  • Rohling, E. J., , Q. S. Liu, , A. P. Roberts, , J. D. Stanford, , S. O. Rasmussen, , P. L. Langen, , and M. Siddall, 2009: Controls on the East Asian monsoon during the last glacial cycle, based on comparison between Hulu Cave and polar ice-core records. Quat. Sci. Rev., 28, 32943302, doi:10.1016/j.quascirev.2009.09.007.

    • Search Google Scholar
    • Export Citation
  • Shell, K. M., , J. T. Kiehl, , and C. A. Shields, 2008: Using the radiative kernel technique to calculate climate feedbacks in NCAR’s Community Atmospheric Model. J. Climate, 21, 22692282.

    • Search Google Scholar
    • Export Citation
  • Shemesh, A., , D. Hodell, , X. Crosta, , S. Kanfoush, , C. Charles, , and T. Guilderson, 2002: Sequence of events during the last deglaciation in Southern Ocean sediments and Antarctic ice cores. Paleoceanography, 17, 1056, doi:10.1029/2000PA000599.

    • Search Google Scholar
    • Export Citation
  • Soden, B. J., , I. M. Held, , R. Colman, , K. M. Shell, , J. T. Kiehl, , and C. A. Shields, 2008: Quantifying climate feedbacks using radiative kernels. J. Climate, 21, 35043520.

    • Search Google Scholar
    • Export Citation
  • Steffensen, J. P., and Coauthors, 2008: High-resolution Greenland ice core data show abrupt climate change happens in few years. Science, 321, 680684.

    • Search Google Scholar
    • Export Citation
  • Stocker, T. F., , and S. J. Johnsen, 2003: A minimum thermodynamic model for the bipolar seesaw. Paleoceangraphy, 18, 1087, doi:10.1029/2003PA000920.

    • Search Google Scholar
    • Export Citation
  • Stouffer, R. J., and Coauthors, 2006: Investigating the causes of the response of the thermohaline circulation to past and future climate changes. J. Climate, 19, 13651387.

    • Search Google Scholar
    • Export Citation
  • Stouffer, R. J., , D. Seidov, , and B. J. Haupt, 2007: Climate response to external sources of freshwater: North Atlantic versus the Southern Ocean. J. Climate, 20, 436448.

    • Search Google Scholar
    • Export Citation
  • Svensson, A., , P. E. Biscaye, , and F. E. Grousset, 2000: Characterization of late glacial continental dust in the Greenland Ice Core Project ice core. J. Geophys. Res., 105 (D4), 46374656.

    • Search Google Scholar
    • Export Citation
  • Terray, L., , and C. Cassou, 2002: Tropical Atlantic sea surface temperature forcing of quasi-decadal climate variability over the North Atlantic–European region. J. Climate, 15, 31703187.

    • Search Google Scholar
    • Export Citation
  • Timmermann, A., and Coauthors, 2010: Towards a quantitative understanding of millennial-scale Antarctic warming events. Quat. Sci. Rev., 29, 7485.

    • Search Google Scholar
    • Export Citation
  • Wang, Y. J., , H. Cheng, , R. L. Edwards, , Z. S. 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, 23452348, doi:10.1126/science.1064618.

    • Search Google Scholar
    • Export Citation
  • Wang, Y. J., and Coauthors, 2008: Millennial- and orbital-scale changes in the East Asian monsoon over the past 224,000 years. Nature, 451, 10901093.

    • Search Google Scholar
    • Export Citation
  • Weaver, A. J., , O. A. Saenko, , P. U. Clark, , and J. X. Mitrovica, 2003: Meltwater pulse 1a from Antarctica as a trigger for the Bølling-Allerød warm interval. Science, 209, 17091713.

    • Search Google Scholar
    • Export Citation
  • Webster, P. J., 2004: The elementary Hadley circulation. The Hadley Circulation: Present, Past, and Future, H. F. Diaz and R. S. Bradley, Eds., Springer, 9–60. [Available online at http://link.springer.com/chapter/10.1007%2F978-1-4020-2944-8_1.]

  • Yoshimori, M., , and A. J. Broccoli, 2008: Equilibrium response of an atmosphere–mixed layer ocean model to different radiative forcing agents: Global and zonal mean response. J. Climate, 21, 43994423.

    • Search Google Scholar
    • Export Citation
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Southward Intertropical Convergence Zone Shifts and Implications for an Atmospheric Bipolar Seesaw

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  • 1 Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark, and Carnegie Institution for Science, Department of Global Ecology, Stanford University, Stanford, California
  • | 2 Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, and Danish Climate Centre, Danish Meteorological Institute, Copenhagen, Denmark
  • | 3 Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
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Abstract

In this study, southward intertropical convergence zone (ITCZ) shifts are investigated in three different scenarios: Northern Hemispheric cooling, Southern Hemispheric warming, and a bipolar seesaw-like forcing that combines the latter two. The experiments demonstrate the mutual effects that northern- and southern-high-latitude forcings exert on tropical precipitation, suggesting a time-scale-dependent dominance of northern versus southern forcings. In accordance with this, two-phase tropical precipitation shifts are suggested, involving a fast component dominated by the high-northern-latitude forcing and a slower component due to the southern-high-latitude forcing. The results may thus be useful for the future understanding and interpretation of high-resolution tropical paleoprecipitation proxies and their relation to high-latitude records (e.g., ice core data). The experiments also show that Southern Ocean warming has a global impact, affecting both the tropics and northern extratropics, as seen in a southward ITCZ shift and mid- and high-latitude North Atlantic surface temperature and wind changes. In terms of dynamical considerations, the tropical circulation response to high-latitude forcing is found to be nonlinear: the atmospheric heat transport and Hadley cell anomalies differ significantly (in magnitude) when comparing the warming and cooling experiments. These are related to different interhemispheric temperature gradients that are altered mainly by nonlinearities in water vapor response. Decomposition of the top-of-the-atmosphere flux response into atmospheric feedback effects shows the dominance of water vapor and cloud feedbacks in the tropics, with the longwave cloud feedback effect governing the overall cloud response.

Corresponding author address: Ivana Cvijanovic, Centre for Ice and Climate, Juliane Maries Vej 30, 2100 Copenhagen, Denmark. E-mail: ivanacv@nbi.ku.dk

Abstract

In this study, southward intertropical convergence zone (ITCZ) shifts are investigated in three different scenarios: Northern Hemispheric cooling, Southern Hemispheric warming, and a bipolar seesaw-like forcing that combines the latter two. The experiments demonstrate the mutual effects that northern- and southern-high-latitude forcings exert on tropical precipitation, suggesting a time-scale-dependent dominance of northern versus southern forcings. In accordance with this, two-phase tropical precipitation shifts are suggested, involving a fast component dominated by the high-northern-latitude forcing and a slower component due to the southern-high-latitude forcing. The results may thus be useful for the future understanding and interpretation of high-resolution tropical paleoprecipitation proxies and their relation to high-latitude records (e.g., ice core data). The experiments also show that Southern Ocean warming has a global impact, affecting both the tropics and northern extratropics, as seen in a southward ITCZ shift and mid- and high-latitude North Atlantic surface temperature and wind changes. In terms of dynamical considerations, the tropical circulation response to high-latitude forcing is found to be nonlinear: the atmospheric heat transport and Hadley cell anomalies differ significantly (in magnitude) when comparing the warming and cooling experiments. These are related to different interhemispheric temperature gradients that are altered mainly by nonlinearities in water vapor response. Decomposition of the top-of-the-atmosphere flux response into atmospheric feedback effects shows the dominance of water vapor and cloud feedbacks in the tropics, with the longwave cloud feedback effect governing the overall cloud response.

Corresponding author address: Ivana Cvijanovic, Centre for Ice and Climate, Juliane Maries Vej 30, 2100 Copenhagen, Denmark. E-mail: ivanacv@nbi.ku.dk
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