• Alexander, M. A., , I. Blade, , M. Newman, , J. R. Lanzante, , N.-C. Lau, , and J. D. Scott, 2002: The atmospheric bridge: The influence of ENSO teleconnections on air–sea interaction over the global oceans. J. Climate, 15, 22052231.

    • Search Google Scholar
    • Export Citation
  • Barnett, T., , D. W. Pierce, , M. Latif, , D. Dommenget, , and R. Saravana, 1999: Interdecadal interactions between the tropics and the midlatitudes in the Pacific basin. Geophys. Res. Lett., 26, 615618.

    • Search Google Scholar
    • Export Citation
  • Bryden, H. L., , H. R. Longworth, , and S. A. Cunningham, 2005: Slowing of the Atlantic meridional overturning circulation at 25°N. Nature, 438, 655657.

    • Search Google Scholar
    • Export Citation
  • Cane, M. A., , A. C. Clement, , A. Kaplan, , Y. Kushnir, , D. Pozdnyakov, , R. Seager, , S. E. Zebiak, , and R. Murtugudde, 1997: Twentieth-century sea surface temperature trends. Science, 275, 957960.

    • Search Google Scholar
    • Export Citation
  • Chang, P., and Coauthors, 2008: Oceanic link between abrupt changes in the North Atlantic Ocean and the African monsoon. Nat. Geosci., 1, 444448.

    • Search Google Scholar
    • Export Citation
  • Clement, A. C., , R. Seager, , M. A. Cane, , and S. E. Zebiak, 1996: An ocean dynamic thermostat. J. Climate, 9, 21902196.

  • Curry, R. G., , M. S. McCartney, , and T. M. Joyce, 1998: Oceanic transport of subpolar climate signals to mid-depth subtropical waters. Nature, 391, 575577.

    • Search Google Scholar
    • Export Citation
  • Enfield, D. B., , and D. A. Mayer, 1997: Tropical Atlantic sea surface temperature variability and its relation to El Niño–Southern Oscillation. J. Geophys. Res., 102, 929945.

    • Search Google Scholar
    • Export Citation
  • Feistel, R., 2005: Numerical implementation and oceanographic application of the Gibbs thermodynamic potential of seawater. Ocean Sci., 1, 916.

    • Search Google Scholar
    • Export Citation
  • Fratantoni, D. M., , W. E. Johns, , T. L. Townsend, , and H. E. Hurlburt, 2000: Low-latitude circulation and mass transport pathways in a model of tropical Atlantic Ocean. J. Phys. Oceanogr., 30, 19441966.

    • Search Google Scholar
    • Export Citation
  • Gu, D., , and S. G. H. Philander, 1997: Interdecadal climate fluctuations that depend on exchanges between the tropics and extratropics. Science, 275, 805807.

    • Search Google Scholar
    • Export Citation
  • Hazeleger, W., , and S. Drijfhout, 2006: Subtropical cells and meridional overturning circulation pathways in the tropical Atlantic. J. Geophys. Res., 111, C03013, doi:10.1029/2005JC002942.

    • Search Google Scholar
    • Export Citation
  • Hoerling, M. P., , J. W. Hurrell, , and T. Xu, 2001: Tropical origins for recent North Atlantic climate change. Science, 292, 9092.

  • Jacob, R. L., 1997: Low frequency variability in a simulated atmosphere–ocean system. Ph.D. thesis, University of Wisconsin—Madison, 155 pp.

  • Kawase, M., 1987: Establishment of deep ocean circulation driven by deep-water production. J. Phys. Oceanogr., 17, 22972317.

  • Kleeman, R., , J. P. McCreary, , and B. A. Klinger, 1999: A mechanism for generating ENSO decadal variability. Geophys. Res. Lett., 26, 17431746.

    • Search Google Scholar
    • Export Citation
  • Lau, N.-C., 1997: Interactions between global SST anomalies and the midlatitude atmospheric circulation. Bull. Amer. Meteor. Soc., 78, 2133.

    • Search Google Scholar
    • Export Citation
  • Liu, Z., , and H. Yang, 2003: Extratropical control of tropical climate, the atmospheric bridge and oceanic tunnel. Geophys. Res. Lett., 30, 1230, doi:10.1029/2002GL016492.

    • Search Google Scholar
    • Export Citation
  • Liu, Z., , S. Vavrus, , F. He, , N. Wen, , and Y. Zhong, 2005: Rethinking tropical ocean response to global warming: The enhanced equatorial warming. J. Climate, 18, 46844700.

    • Search Google Scholar
    • Export Citation
  • Lu, J., , R. J. Greatbatch, , and K. A. Peterson, 2004: Trend in Northern Hemisphere winter atmospheric circulation during the last half of the twentieth century. J. Climate, 17, 37453760.

    • Search Google Scholar
    • Export Citation
  • Lysne, J., , P. Chang, , and B. Giese, 1997: Impact of the extratropical Pacific on equatorial variability. Geophys. Res. Lett., 24, 25892592.

    • Search Google Scholar
    • Export Citation
  • Manabe, S., , and R. J. Stouffer, 1995: Simulation of abrupt climate change induced by freshwater input to the North Atlantic Ocean. Nature, 378, 165167.

    • Search Google Scholar
    • Export Citation
  • Matei, D., , N. Keenlyside, , M. Latif, , and J. Jungclaus, 2008: Subtropical forcing of tropical Pacific climate and decadal ENSO modulation. J. Climate, 21, 46914709.

    • Search Google Scholar
    • Export Citation
  • McCreary, J., , and P. Lu, 1994: On the interaction between the subtropical and the equatorial oceans: The subtropical cell. J. Phys. Oceanogr., 24, 466497.

    • Search Google Scholar
    • Export Citation
  • McPhaden, M. J., , and D. X. Zhang, 2002: Slowdown of the meridional overturning circulation in the upper Pacific Ocean. Nature, 415, 603608.

    • Search Google Scholar
    • Export Citation
  • Mignot, J., , A. Ganopolski, , and A. Levermann, 2007: Atlantic subsurface temperatures: Response to a shutdown of the overturning circulation and consequences for its recovery. J. Climate, 20, 48844898.

    • Search Google Scholar
    • Export Citation
  • Nonaka, M., , S.-P. Xie, , and J. P. McCreary, 2002: Decadal variations in the subtropical cells and equatorial Pacific SST. Geophys. Res. Lett., 29, 1116, doi:10.1029/2001GL013717.

    • Search Google Scholar
    • Export Citation
  • Pierce, D. W., , T. P. Barnett, , and M. Latif, 2000: Connections between the Pacific Ocean tropics and midlatitudes on decadal timescales. J. Climate, 13, 11731194.

    • Search Google Scholar
    • Export Citation
  • Rodgers, K., , M. A. Cane, , N. Naik, , and D. Schrag, 1999: The role of the Indonesian throughflow in equatorial Pacific thermocline ventilation. J. Geophys. Res., 104, 20 55120 570.

    • Search Google Scholar
    • Export Citation
  • Schneider, E. K., , R. S. Lindzen, , and B. P. Kirtman, 1997: A tropical influence on global climate. J. Atmos. Sci., 54, 13491358.

  • Stocker, T. F., , and D. G. Wright, 1991: Rapid transitions of the ocean’s deep circulation induced by changes in the surface water fluxes. Nature, 351, 729732.

    • Search Google Scholar
    • Export Citation
  • Stouffer, R. J., , and S. Manabe, 2003: Equilibrium response of thermohaline circulation to large changes in atmospheric CO2 concentration. Climate Dyn., 20, 759773.

    • Search Google Scholar
    • Export Citation
  • Sutton, R. T., , and D. L. R. Hodson, 2007: Climate response to basin-scale warming and cooling of the North Atlantic Ocean. J. Climate, 20, 891907.

    • Search Google Scholar
    • Export Citation
  • Wang, C., 2002: Atmospheric circulation cells associated with the El Niño–Southern Oscillation. J. Climate, 15, 399419.

  • Wang, C., , S. Dong, , and E. Munoz, 2010a: Seawater density variations in the North Atlantic and the Atlantic meridional overturning circulation. Climate Dyn., 34, 953968, doi:10.1007/s00382-009-0560-5.

    • Search Google Scholar
    • Export Citation
  • Wang, C., , S.-K. Lee, , and C. R. Mechoso, 2010b: Interhemispheric influence of the Atlantic warm pool on the southeastern Pacific. J. Climate, 23, 404418.

    • Search Google Scholar
    • Export Citation
  • Wu, L., , Z. Liu, , R. Gallimore, , R. Jacob, , D. Lee, , and Y. Zhong, 2003: Pacific decadal variability: The tropical Pacific mode and the North Pacific mode. J. Climate, 16, 11011120.

    • Search Google Scholar
    • Export Citation
  • Yang, H., , and Z. Liu, 2005: Tropical-extratropical climate interaction as revealed in idealized coupled climate model experiments. Climate Dyn., 24, 863879.

    • Search Google Scholar
    • Export Citation
  • Yang, H., , and L. Wang, 2008: Estimating the nonlinear response of tropical ocean to extratropical forcing in a coupled climate model. Geophys. Res. Lett., 35, L15705, doi:10.1029/2008GL034256.

    • Search Google Scholar
    • Export Citation
  • Yang, H., , and Q. Zhang, 2008: Anatomizing the ocean role in ENSO changes under global warming. J. Climate, 21, 65396555.

  • Yang, H., , H. Jiang, , and B. Tan, 2005: Asymmetric impact of the North and South Pacific on the equator in a coupled climate model. Geophys. Res. Lett., 32, L05604, doi:10.1029/2004GL021925.

    • Search Google Scholar
    • Export Citation
  • Yin, F. Y., , and E. S. Sarachik, 1995: Interdecadal thermohaline oscillations in a sector ocean general circulation model: Advective and convective processes. J. Phys. Oceanogr., 25, 24652484.

    • Search Google Scholar
    • Export Citation
  • Yu, L., , and M. M. Rienecker, 1999: Mechanisms for the Indian Ocean warming during 1997-1998 El Niño. Geophys. Res. Lett., 26, 735738.

    • Search Google Scholar
    • Export Citation
  • Yu, Y., , and D.-Z. Sun, 2009: Response of ENSO and the mean state of the tropical Pacific to extratropical cooling and warming: A study using the IAP coupled model. J. Climate, 22, 59025917.

    • Search Google Scholar
    • Export Citation
  • Zhang, D. X., , M. J. McPhaden, , and W. E. Johns, 2003: Observational evidence for flow between the subtropical and tropical Atlantic: The Atlantic subtropical cells. J. Phys. Oceanogr., 33, 17831797.

    • Search Google Scholar
    • Export Citation
  • Zhang, D. X., , R. Msadek, , M. J. McPhaden, , and T. Delworth, 2011: Multidecadal variability of the North Brazil Current and its connection to the Atlantic meridional overturning circulation. J. Geophys. Res., in press, doi:10.1029/2010JC006812.

    • Search Google Scholar
    • Export Citation
  • Zhang, R., , and T. Delworth, 2006: Impact of Atlantic multidecadal oscillations on India/Sahel rainfall and Atlantic hurricanes. Geophys. Res. Lett., 33, L17712, doi:10.1029/2006GL026267.

    • Search Google Scholar
    • Export Citation
  • Zhang, X., , J. Sheng, , and A. Shabbar, 1998: Modes of interannual and interdecadal variability of Pacific SST. J. Climate, 11, 25562569.

    • Search Google Scholar
    • Export Citation
  • Zhang, Y., , J. M. Wallace, , and N. Iwasaka, 1996: Is climate variability over the North Pacific a linear response to ENSO? J. Climate, 9, 14681478.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 16 16 1
PDF Downloads 8 8 1

Tropical Oceanic Response to Extratropical Thermal Forcing in a Coupled Climate Model: A Comparison between the Atlantic and Pacific Oceans

View More View Less
  • 1 Laboratory for Climate and Ocean-Atmosphere Studies, and Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing, China
© Get Permissions
Restricted access

Abstract

The tropical oceanic response to the extratropical thermal forcing is quantitatively estimated in a coupled climate model. This work focuses on comparison of the responses between the tropical Atlantic and Pacific. Under the same extratropical forcing, the tropical sea surface temperature responses are comparable. However, the responses in the tropical subsurface in the two oceans are distinct. The tropical subsurface response in the Atlantic can be twice of that in the Pacific. The maximum subsurface temperature change in the tropical Pacific occurs in the eastern lower thermocline, while that in the tropical Atlantic occurs in the west and well below the lower thermocline. The different responses in the tropical Atlantic and Pacific are closely related to the different changes in the meridional overturning circulations. The Pacific shallow overturning circulation, or the subtropical cell, tends to slow down (speed up) in response to the extratropical warming (cooling) forcing. The changes in the upwelling in the eastern equatorial Pacific as well as the shallow subduction from the extratropical southern Pacific along the eastern boundary are accountable for the eastern Pacific temperature change. The Atlantic overturning circulation consists of the shallow subtropical cell and the deep thermohaline circulation. A weakened thermohaline circulation will result in a strengthened northern subtropical cell, in which the change in the lower branch, or the low-latitude North Brazil Current, can cause strong response below the western tropical thermocline. Here the coastal Kelvin wave along the western boundary on the intermediate isopycnal level also plays an important role in the equatorward conveying of the climate anomalies in the mid-to-high-latitude Atlantic, particularly during the initial stage of the extratropical forcing.

Department of Atmospheric and Oceanic Sciences Contribution Number 010.

Corresponding author address: Haijun Yang, Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, 209 Chengfu Rd., Beijing 100871, China. E-mail: hjyang@pku.edu.cn

Abstract

The tropical oceanic response to the extratropical thermal forcing is quantitatively estimated in a coupled climate model. This work focuses on comparison of the responses between the tropical Atlantic and Pacific. Under the same extratropical forcing, the tropical sea surface temperature responses are comparable. However, the responses in the tropical subsurface in the two oceans are distinct. The tropical subsurface response in the Atlantic can be twice of that in the Pacific. The maximum subsurface temperature change in the tropical Pacific occurs in the eastern lower thermocline, while that in the tropical Atlantic occurs in the west and well below the lower thermocline. The different responses in the tropical Atlantic and Pacific are closely related to the different changes in the meridional overturning circulations. The Pacific shallow overturning circulation, or the subtropical cell, tends to slow down (speed up) in response to the extratropical warming (cooling) forcing. The changes in the upwelling in the eastern equatorial Pacific as well as the shallow subduction from the extratropical southern Pacific along the eastern boundary are accountable for the eastern Pacific temperature change. The Atlantic overturning circulation consists of the shallow subtropical cell and the deep thermohaline circulation. A weakened thermohaline circulation will result in a strengthened northern subtropical cell, in which the change in the lower branch, or the low-latitude North Brazil Current, can cause strong response below the western tropical thermocline. Here the coastal Kelvin wave along the western boundary on the intermediate isopycnal level also plays an important role in the equatorward conveying of the climate anomalies in the mid-to-high-latitude Atlantic, particularly during the initial stage of the extratropical forcing.

Department of Atmospheric and Oceanic Sciences Contribution Number 010.

Corresponding author address: Haijun Yang, Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, 209 Chengfu Rd., Beijing 100871, China. E-mail: hjyang@pku.edu.cn
Save