• Alexeev, V. A., , P. L. Langen, , and J. R. Bates, 2005: Polar amplification of surface warming on an aquaplanet in ‘‘ghost forcing’’ experiments without sea ice feedbacks. Climate Dyn., 24, 655666.

    • Search Google Scholar
    • Export Citation
  • Cai, M., , and J. Lu, 2007: Dynamical greenhouse-plus feedback and polar warming amplification. Part II: Meridional and vertical asymmetries of the global warming. Climate Dyn., 29, 375391.

    • Search Google Scholar
    • Export Citation
  • Cubasch, U., and Coauthors, 2001: Projections of future climate change. Climate Change 2001: The Scientific Basis, J. T. Houghton et al., Eds., Cambridge University Press, 525–582.

  • Curry, R., , and C. Mauritzen, 2005: Dilution of the northern North Atlantic Ocean in recent decades. Science, 308, 17721774.

  • Curry, R., , B. Dickson, , and I. Yashayaev, 2003: A change in the freshwater balance of the Atlantic Ocean over the past four decades. Nature, 426, 826829.

    • Search Google Scholar
    • Export Citation
  • Dai, A., , I. Y. Fung, , and A. D. Del Genio, 1997: Surface observed global land precipitation variations during 1900–88. J. Climate, 10, 29432962.

    • Search Google Scholar
    • Export Citation
  • Fedorov, A. V., , R. Pacanowski, , S. G. Philander, , and G. Boccaletti, 2004: The effect of salinity on the wind-driven circulation and the thermal structure of the upper ocean. J. Phys. Oceanogr., 34, 19491966.

    • Search Google Scholar
    • Export Citation
  • Fedorov, A. V., , M. Barreiro, , G. Boccaletti, , R. Pacanowski, , and S. G. Philander, 2007: The freshening of surface waters in high latitudes: Effects on the thermohaline and wind-driven circulations. J. Phys. Oceanogr., 37, 896907.

    • Search Google Scholar
    • Export Citation
  • Fu, Q., , C. M. Johanson, , J. M. Wallace, , and T. Reichler, 2006: Enhanced mid-latitude troposphere warming in satellite measurements. Science, 312, 11791179.

    • Search Google Scholar
    • Export Citation
  • Hall, A., , and S. Manabe, 1999: The role of water vapor feedback in unperturbed climate variability and global warming. J. Climate, 12, 23272346.

    • Search Google Scholar
    • Export Citation
  • Held, I. M., , and B. J. Soden, 2006: Robust responses of the hydrologic cycle to global warming. J. Climate, 19, 56865699.

  • Huang, B., , and V. M. Mehta, 2005: Response of the Pacific and Atlantic Oceans to interannual variations in net atmospheric freshwater. J. Geophys. Res., 110, C08008, doi:10.1029/2004JC002830.

    • Search Google Scholar
    • Export Citation
  • Huang, B., , V. M. Mehta, , and N. Schneider, 2005: Oceanic response to idealized net atmospheric freshwater in the Pacific at the decadal time scale. J. Phys. Oceanogr., 35, 24672486.

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

  • Liu, Z., 1999: Forced planetary wave response in a thermocline gyre. J. Phys. Oceanogr., 29, 10361055.

  • Liu, Z., , J. Kutzbach, , and L. Wu, 2000: Modeling climatic shift of El Niño variability in the Holocene. Geophys. Res. Lett., 27, 22652268.

    • 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., , G. A. Vecchi, , and T. Reichler, 2007: Expansion of the Hadley cell under global warming. Geophys. Res. Lett., 34, L06805, doi:10.1029/2006GL028443.

    • Search Google Scholar
    • Export Citation
  • Lukas, G., , and F. Santiago-Mandujano, 2008: Interannual to interdecadal salinity variations observed near Hawaii: Local and remote forcing by surface freshwater fluxes. Oceanography, 21, 4655.

    • Search Google Scholar
    • Export Citation
  • Ma, H., , and L. Wu, 2011: Global teleconnections in response to freshening over the Antarctic ocean. J. Climate, 24, 10711088.

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

    • Search Google Scholar
    • Export Citation
  • Mitas, C. M., , and A. Clement, 2006: Recent behavior of the Hadley cell and tropical thermodynamics in climate models and reanalyses. Geophys. Res. Lett., 33, L01810, doi:10.1029/2005GL024406.

    • Search Google Scholar
    • Export Citation
  • Quan, X., , H. F. Diaz, , and M. P. Hoerling, 2004: Changes in the tropical Hadley cell since 1950. The Hadley Circulation: Past, Present, and Future, H. F. Diaz and R. S. Bradley, Eds., Advances in Global Change Research, Vol. 21, Springer, 85–120.

  • Seager, R., , and N. Naik, 2010: Thermodynamic and dynamic mechanisms for large-scale changes in the hydrological cycle in response to global warming. J. Climate, 23, 46514668.

    • Search Google Scholar
    • Export Citation
  • Seidel, D. J., , and R. J. Randel, 2007: Recent widening of the tropical belt: Evidence from tropopause observations. J. Geophys. Res., 112, D20113, doi:10.1029/2007JD008861.

    • Search Google Scholar
    • Export Citation
  • Soden, B. J., 2000: Enlightening water vapor. Nature, 406, 247248.

  • Soden, B. J., , R. T. Wetherald, , G. L. Stenchikov, , and A. Robock, 2002: Global cooling after the eruption of Mount Pinatubo: A test of climate feedback by water vapor. Science, 296, 727730.

    • Search Google Scholar
    • Export Citation
  • Soden, B. J., , D. L. Jackson, , V. Ramaswamy, , M. D. Schwarzkopf, , and X. Huang, 2005: The radiative signature of upper tropospheric moistening. Science, 310, 841844.

    • Search Google Scholar
    • Export Citation
  • Williams, P. D., , E. Guilyardi, , R. Sutton, , J. Gregory, , and G. Madec, 2006: On the climate response of the low-latitude Pacific Ocean to changes in the global freshwater cycle. Climate Dyn., 27, 593611.

    • Search Google Scholar
    • Export Citation
  • Williams, P. D., , E. Guilyardi, , R. Sutton, , J. Gregory, , and G. Madec, 2007: A new feedback on climate change from the hydrological cycle. Geophys. Res. Lett., 34, L08706, doi:10.1029/2007GL029275.

    • Search Google Scholar
    • Export Citation
  • Wong, A. P. S., , N. L. Bindoff, , and J. A. Church, 1999: Large-scale freshening of intermediate waters in the Pacific and Indian Oceans. Nature, 400, 440443.

    • 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
  • Xie, S.-P., , C. Deser, , G. A. Vecchi, , J. Ma, , H. Teng, , and A. T. Wittenberg, 2010: Global warming pattern formation: Sea surface temperature and rainfall. J. Climate, 23, 966986.

    • Search Google Scholar
    • Export Citation
  • Zhang, L., , L. Wu, , and J. Zhang, 2011a: Coupled ocean–atmosphere responses to recent freshwater flux changes over the Kuroshio–Oyashio Extension region. J. Climate, 24, 15071524.

    • Search Google Scholar
    • Export Citation
  • Zhang, L., , L. Wu, , and J. Zhang, 2011b: Simulated response to recent freshwater flux change over the Gulf Stream and its extension: Coupled ocean–atmosphere adjustment and Atlantic–Pacific teleconnection. J. Climate, 24, 39713988.

    • Search Google Scholar
    • Export Citation
  • Zhong, Y., , and Z. Liu, 2009: On the mechanism of Pacific multidecadal climate variability in CCSM3: The role of the subpolar North Pacific Ocean. J. Phys. Oceanogr., 39, 20522076.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 21 21 9
PDF Downloads 12 12 4

Can Oceanic Freshwater Flux Amplify Global Warming?

View More View Less
  • 1 Physical Oceanography Laboratory, Ocean University of China, Qingdao, China
© Get Permissions
Restricted access

Abstract

The roles of freshwater flux (defined as evaporation minus precipitation) changes in global warming are studied using simulations of a climate model in which the freshwater flux changes are suppressed in the presence of a doubling of CO2 concentration. The model simulations demonstrate that the warm climate leads to an acceleration of the global water cycle, which causes freshening in the high latitudes and salinification in the subtropics and midlatitudes. It is found that the freshwater flux changes tend to amplify rather than suppress global warming. Over the global scale, this amplification is largely associated with high-latitude freshening in a warm climate, which leads to a shoaling of the mixed layer depth, a weakening of the vertical mixing, and thus a trapping of CO2-induced warming in the surface ocean. The latitudinal distribution of SST changes due to the effects of freshwater flux changes in a warm climate is complicated, involving anomalous advection induced by both salinity and wind stress changes. In addition, atmospheric feedbacks associated with global warming also amplify the SST warming.

Corresponding author address: Dr. Lixin Wu, Physical Oceanography Laboratory, Ocean University of China, 5 Yushan Road, Qingdao 266003, China. E-mail: lxwu@ouc.edu.cn

Abstract

The roles of freshwater flux (defined as evaporation minus precipitation) changes in global warming are studied using simulations of a climate model in which the freshwater flux changes are suppressed in the presence of a doubling of CO2 concentration. The model simulations demonstrate that the warm climate leads to an acceleration of the global water cycle, which causes freshening in the high latitudes and salinification in the subtropics and midlatitudes. It is found that the freshwater flux changes tend to amplify rather than suppress global warming. Over the global scale, this amplification is largely associated with high-latitude freshening in a warm climate, which leads to a shoaling of the mixed layer depth, a weakening of the vertical mixing, and thus a trapping of CO2-induced warming in the surface ocean. The latitudinal distribution of SST changes due to the effects of freshwater flux changes in a warm climate is complicated, involving anomalous advection induced by both salinity and wind stress changes. In addition, atmospheric feedbacks associated with global warming also amplify the SST warming.

Corresponding author address: Dr. Lixin Wu, Physical Oceanography Laboratory, Ocean University of China, 5 Yushan Road, Qingdao 266003, China. E-mail: lxwu@ouc.edu.cn
Save