• Arakawa, O., and A. Kitoh, 2004: Comparison of local precipitation–SST relationship between the observation and a reanalysis dataset. Geophys. Res. Lett., 31 , L12206. doi:10.1029/2004GL020283.

    • Search Google Scholar
    • Export Citation
  • Ashok, K., Z. Guan, and T. Yamagata, 2001: Impact of the Indian Ocean dipole on the relationship between the Indian monsoon rainfall and ENSO. Geophys. Res. Lett., 28 , 44994502.

    • Search Google Scholar
    • Export Citation
  • Ashok, K., Z. Guan, and T. Yamagata, 2003: Influence of the Indian Ocean dipole on the Australian winter rainfall. Geophys. Res. Lett., 30 , 1821. doi:10.1029/2003GL017926.

    • Search Google Scholar
    • Export Citation
  • Cai, W., P. H. Whetton, and D. J. Karoly, 2003: The response of the Antarctic Oscillation to increasing and stabilized atmospheric CO2. J. Climate, 16 , 15251538.

    • Search Google Scholar
    • Export Citation
  • Cai, W., T. Cowan, and A. Sullivan, 2009: Recent unprecedented skewness towards positive Indian Ocean dipole occurrences and its impact on Australian rainfall. Geophys. Res. Lett., 36 , L11705. doi:10.1029/2009GL037604.

    • Search Google Scholar
    • Export Citation
  • 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
  • Drosdowsky, W., and L. E. Chambers, 2001: Near-global sea surface temperature anomalies as predictors of Australian seasonal rainfall. J. Climate, 14 , 16771687.

    • Search Google Scholar
    • Export Citation
  • Du, Y., and S. Xie, 2008: Role of atmospheric adjustments in the tropical Indian Ocean warming during the 20th century in climate models. Geophys. Res. Lett., 35 , L08712. doi:10.1029/2008GL033631.

    • Search Google Scholar
    • Export Citation
  • Efron, B., 1982: The Jackknife, the Bootstrap, and Other Resampling Plans. Society for Industrial and Applied Mathematics, 92 pp.

  • England, M. H., C. C. Ummenhofer, and A. Santoso, 2006: Interannual rainfall extremes over southwest Western Australia linked to Indian Ocean climate variability. J. Climate, 19 , 19481969.

    • Search Google Scholar
    • Export Citation
  • Giannini, A., R. Saravanan, and P. Chang, 2003: Oceanic forcing of Sahel rainfall on interannual to interdecadal time scales. Science, 302 , 10271030.

    • Search Google Scholar
    • Export Citation
  • Gillett, N. P., and D. W. J. Thompson, 2003: Simulation of recent Southern Hemisphere climate change. Science, 302 , 273275.

  • Hack, J. J., J. M. Caron, S. G. Yeager, K. W. Oleson, M. M. Holland, J. E. Truesdale, and P. J. Rasch, 2006: Simulation of the global hydrological cycle in the CCSM Community Atmosphere Model Version 3 (CAM3): Mean features. J. Climate, 19 , 21992221.

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

  • Hoerling, M. P., and A. Kumar, 2003: The perfect ocean for drought. Science, 299 , 691694.

  • Hoerling, M. P., J. W. Hurrell, T. Xu, G. T. Bates, and A. S. Phillips, 2004: Twentieth century North Atlantic climate change. Part II: Understanding the effect of Indian Ocean warming. Climate Dyn., 23 , 391405.

    • Search Google Scholar
    • Export Citation
  • Kiktev, D., D. M. H. Sexton, L. Alexander, and C. K. Folland, 2003: Comparison of modeled and observed trends in indices of daily climate extremes. J. Climate, 16 , 35603571.

    • Search Google Scholar
    • Export Citation
  • Kumar, A., F. Yang, L. Goddard, and S. Schubert, 2004: Differing trends in the tropical surface temperatures and precipitation over land and oceans. J. Climate, 17 , 653664.

    • Search Google Scholar
    • Export Citation
  • Lavery, B., G. Joung, and N. Nicholls, 1997: An extended high-quality historical rainfall dataset for Australia. Aust. Meteor. Mag., 46 , 2738.

    • Search Google Scholar
    • Export Citation
  • Marshall, G. J., 2003: Trends in the southern annular mode from observations and reanalyses. J. Climate, 16 , 41344143.

  • Meneghini, B., I. Simmonds, and I. N. Smith, 2006: Association between Australian rainfall and the southern annular mode. Int. J. Climatol., 27 , 109121.

    • Search Google Scholar
    • Export Citation
  • Nicholls, N., 1989: Sea surface temperature and Australian winter rainfall. J. Climate, 2 , 965973.

  • Nicholls, N., 2006: Detecting and attributing Australian climate change: A review. Aust. Meteor. Mag., 55 , 199211.

  • Nicholls, N., 2008: Recent trends in the seasonal and temporal behaviour of the El Niño–Southern Oscillation. Geophys. Res. Lett., 35 , L19703. doi:10.1029/2008GL034499.

    • Search Google Scholar
    • Export Citation
  • Quartly, G. D., E. A. Kyte, M. A. Srokosz, and M. N. Tsimplis, 2007: An intercomparison of global oceanic precipitation climatologies. J. Geophys. Res., 112 , D10121. doi:10.1029/2006JD007810.

    • Search Google Scholar
    • Export Citation
  • Rayner, N. A., D. E. Parker, E. B. Horton, C. K. Folland, L. V. Alexander, D. P. Rowell, E. C. Kent, and A. Kaplan, 2003: Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century. J. Geophys. Res., 108 , 4407. doi:10.1029/2002JD002670.

    • Search Google Scholar
    • Export Citation
  • Rotstayn, L. D., and Coauthors, 2007: Have Australian rainfall and cloudiness increased due to the remote effects of Asian anthropogenic aerosols? J. Geophys. Res., 112 , D09202. doi:10.1029/2006JD007712.

    • Search Google Scholar
    • Export Citation
  • Saji, N. H., and T. Yamagata, 2003: Possible impacts of Indian Ocean dipole mode events on global climate. Climate Res., 25 , 151169.

  • Saji, N. H., B. N. Goswami, P. N. Vinayachandran, and T. Yamagata, 1999: A dipole mode in the tropical Indian Ocean. Nature, 401 , 360363.

    • Search Google Scholar
    • Export Citation
  • Sen Gupta, A., and M. H. England, 2006: Coupled ocean–atmosphere–ice response to variations in the southern annular mode. J. Climate, 19 , 44574486.

    • Search Google Scholar
    • Export Citation
  • Shi, G., W. Cai, T. Cowan, J. Ribbe, L. Rotstayn, and M. Dix, 2008a: Variability and trend of northwest Australia rainfall: Observations and coupled climate modeling. J. Climate, 21 , 29382959.

    • Search Google Scholar
    • Export Citation
  • Shi, G., J. Ribbe, W. Cai, and T. Cowan, 2008b: An interpretation of Australian rainfall projections. Geophys. Res. Lett., 35 , L02702. doi:10.1029/2007GL032436.

    • Search Google Scholar
    • Export Citation
  • Smith, I., 2004: An assessment of recent trends in Australian rainfall. Aust. Meteor. Mag., 53 , 163173.

  • Taschetto, A. S., and M. H. England, 2008: Estimating ensemble size requirements of AGCM simulations. Meteor. Atmos. Phys., 100 , 2336.

    • Search Google Scholar
    • Export Citation
  • Taschetto, A. S., and M. H. England, 2009: An analysis of late twentieth century trends in Australian rainfall. Int. J. Climatol., 29 , 791807.

    • Search Google Scholar
    • Export Citation
  • Thompson, D. W. J., and J. M. Wallace, 2000: Annular modes in the extratropical circulation. Part I: Month-to-month variability. J. Climate, 13 , 10001016.

    • Search Google Scholar
    • Export Citation
  • Thompson, D. W. J., S. Lee, and M. P. Baldwin, 2003: Atmospheric processes governing the Northern Hemisphere annular mode/North Atlantic Oscillation. The North Atlantic Oscillation: Climatic Significance and Environmental Impact, Geophys. Monogr., Vol. 134, Amer. Geophys. Union, 81–112.

    • Search Google Scholar
    • Export Citation
  • Ummenhofer, C. C., A. Sen Gupta, M. J. Pook, and M. H. England, 2008: Anomalous rainfall over southwest Western Australia forced by Indian Ocean sea surface temperatures. J. Climate, 21 , 51135134.

    • Search Google Scholar
    • Export Citation
  • Ummenhofer, C. C., A. Sen Gupta, A. S. Taschetto, and M. H. England, 2009: Modulation of Australian precipitation by meridional gradients in east Indian Ocean sea surface temperature. J. Climate, 22 , 55975610.

    • Search Google Scholar
    • Export Citation
  • Vecchi, G. A., B. J. Soden, A. T. Wittenberg, I. M. Held, A. Leetmaa, and M. J. Harrison, 2006: Weakening of tropical Pacific atmospheric circulation due to anthropogenic forcing. Nature, 441 , 7376.

    • Search Google Scholar
    • Export Citation
  • Washington, R., and A. Preston, 2006: Extreme wet years over southern Africa: Role of Indian Ocean sea surface temperatures. J. Geophys. Res., 111 , D15104. doi:10.1029/2005JD006724.

    • Search Google Scholar
    • Export Citation
  • Watterson, I. G., 2001: Wind-induced rainfall and surface temperature anomalies in the Australian region. J. Climate, 14 , 19011922.

  • Yu, L., X. Jin, and R. Weller, 2007: Annual, seasonal, and interannual variability of air–sea heat fluxes in the Indian Ocean. J. Climate, 20 , 31903209.

    • Search Google Scholar
    • Export Citation
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Global and Regional Climate Response to Late Twentieth-Century Warming over the Indian Ocean

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  • 1 Climate Change Research Centre, University of New South Wales, Kensington, New South Wales, Australia
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Abstract

The global and regional climate response to a warming of the Indian Ocean is examined in an ensemble of atmospheric general circulation model experiments. The most marked changes occur over the Indian Ocean, where the increase in tropical SST is found to drive enhanced convection throughout the troposphere. In the extratropics, the warming Indian Ocean is found to induce a significant trend toward the positive phase of the northern annular mode and also to enhance the Southern Hemisphere storm track over Indian Ocean longitudes as a result of stronger meridional temperature gradients. Convective outflow in the upper levels over the warming Indian Ocean leads to a trend in subsidence over the Indian and Asian monsoon regions extending southeastward to Indonesia, the eastern Pacific, and northern Australia. Regional changes in Australia reveal that this anomalous zone of subsidence induces a drying trend in the northern regions of the continent. The long-term rainfall trend is exacerbated over northeastern Australia by the anomalous anticyclonic circulation, which leads to an offshore trend in near-surface winds. The confluence of these two factors leads to a drying signal over northeastern Australia, which is detectable during austral autumn. The rapid, late twentieth-century warming of the Indian Ocean may have contributed to a component of the observed drying trend over northeastern Australia in this season via modifications to the vertical structure of the tropical wind field.

Corresponding author address: Andréa S. Taschetto, Climate Change Research Centre, University of New South Wales, Kensington, NSW 2052, Australia. Email: a.taschetto@unsw.edu.au

Abstract

The global and regional climate response to a warming of the Indian Ocean is examined in an ensemble of atmospheric general circulation model experiments. The most marked changes occur over the Indian Ocean, where the increase in tropical SST is found to drive enhanced convection throughout the troposphere. In the extratropics, the warming Indian Ocean is found to induce a significant trend toward the positive phase of the northern annular mode and also to enhance the Southern Hemisphere storm track over Indian Ocean longitudes as a result of stronger meridional temperature gradients. Convective outflow in the upper levels over the warming Indian Ocean leads to a trend in subsidence over the Indian and Asian monsoon regions extending southeastward to Indonesia, the eastern Pacific, and northern Australia. Regional changes in Australia reveal that this anomalous zone of subsidence induces a drying trend in the northern regions of the continent. The long-term rainfall trend is exacerbated over northeastern Australia by the anomalous anticyclonic circulation, which leads to an offshore trend in near-surface winds. The confluence of these two factors leads to a drying signal over northeastern Australia, which is detectable during austral autumn. The rapid, late twentieth-century warming of the Indian Ocean may have contributed to a component of the observed drying trend over northeastern Australia in this season via modifications to the vertical structure of the tropical wind field.

Corresponding author address: Andréa S. Taschetto, Climate Change Research Centre, University of New South Wales, Kensington, NSW 2052, Australia. Email: a.taschetto@unsw.edu.au

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