Editorial Type:
Article
Article Type:
Research Article

How Stationary Eddies Shape Changes in the Hydrological Cycle: Zonally Asymmetric Experiments in an Idealized GCM

Robert C. Wills California Institute of Technology, Pasadena, California, and ETH Zürich, Zurich, Switzerland

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Tapio Schneider California Institute of Technology, Pasadena, California, and ETH Zürich, Zurich, Switzerland

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Print Publication:
01 May 2016
DOI:
https://doi.org/10.1175/JCLI-D-15-0781.1
Page(s):
3161–3179
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Abstract

Stationary and low-frequency Rossby waves are the primary drivers of extratropical weather variations on monthly and longer time scales. They take the form of persistent highs and lows, which, for example, shape subtropical dry zones and guide extratropical storms. More generally, stationary-eddy circulations, including zonally anomalous tropical overturning circulations, set up large zonal variations in net precipitation (precipitation minus evaporation, P − E). This paper investigates the response of stationary eddies and the zonally asymmetric hydrological cycle to global warming in an idealized GCM, simulating a wide range of climates by varying longwave absorption. The stationary eddies are forced by two idealized zonal asymmetries: a midlatitude Gaussian mountain and an equatorial ocean heat source. Associated with changes in stationary eddies are changes in the zonal variation of the hydrological cycle. Particularly in the subtropics, these simulations show a nearly constant or decreasing amplitude of the zonally anomalous hydrological cycle in climates warmer than modern despite the wet gets wetter, dry gets drier effect associated with increasing atmospheric moisture content. An approximation for zonally anomalous P − E, based on zonal-mean surface specific humidity and stationary-eddy vertical motion, disentangles the roles of thermodynamic and dynamic changes. The approximation shows that changes in the zonally asymmetric hydrological cycle are predominantly controlled by changes in lower-tropospheric vertical motion in stationary eddies.

Publisher’s Note: This article was revised on 22 April 2016 to fix a production error that degraded the quality of Figs. 2, 3, 4, 6, 7, 8, 9, and 11, and to correct typesetting errors for variables containing an overbar and asterisk.

Corresponding author address: Robert C. Wills, Geological Institute, ETH Zurich, Sonneggstrasse 5, 8092 Zurich, Switzerland. E-mail: robert.wills@erdw.ethz.ch

Abstract

Stationary and low-frequency Rossby waves are the primary drivers of extratropical weather variations on monthly and longer time scales. They take the form of persistent highs and lows, which, for example, shape subtropical dry zones and guide extratropical storms. More generally, stationary-eddy circulations, including zonally anomalous tropical overturning circulations, set up large zonal variations in net precipitation (precipitation minus evaporation, P − E). This paper investigates the response of stationary eddies and the zonally asymmetric hydrological cycle to global warming in an idealized GCM, simulating a wide range of climates by varying longwave absorption. The stationary eddies are forced by two idealized zonal asymmetries: a midlatitude Gaussian mountain and an equatorial ocean heat source. Associated with changes in stationary eddies are changes in the zonal variation of the hydrological cycle. Particularly in the subtropics, these simulations show a nearly constant or decreasing amplitude of the zonally anomalous hydrological cycle in climates warmer than modern despite the wet gets wetter, dry gets drier effect associated with increasing atmospheric moisture content. An approximation for zonally anomalous P − E, based on zonal-mean surface specific humidity and stationary-eddy vertical motion, disentangles the roles of thermodynamic and dynamic changes. The approximation shows that changes in the zonally asymmetric hydrological cycle are predominantly controlled by changes in lower-tropospheric vertical motion in stationary eddies.

Publisher’s Note: This article was revised on 22 April 2016 to fix a production error that degraded the quality of Figs. 2, 3, 4, 6, 7, 8, 9, and 11, and to correct typesetting errors for variables containing an overbar and asterisk.

Corresponding author address: Robert C. Wills, Geological Institute, ETH Zurich, Sonneggstrasse 5, 8092 Zurich, Switzerland. E-mail: robert.wills@erdw.ethz.ch
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  • Betts, A. K., 1998: Climate-convection feedbacks: Some further issues. Climatic Change, 39, 35–38, doi:10.1023/A:1005323805826.

  • Boer, G. J., 1982: Diagnostic equations in isobaric coordinates. Mon. Wea. Rev., 110, 1801–1820, doi:10.1175/1520-0493(1982)110<1801:DEIIC>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Bony, S., G. Bellon, D. Klocke, S. Sherwood, S. Fermepin, and S. Denvil, 2013: Robust direct effect of carbon dioxide on tropical circulation and regional precipitation. Nat. Geosci., 6, 447–451, doi:10.1038/ngeo1799.

    • Search Google Scholar
    • Export Citation

  • Bordoni, S., 2007: On the role of eddies in monsoonal circulations: Observations and theory. Ph.D. thesis, University of California, Los Angeles, 195 pp.

  • Bordoni, S., and T. Schneider, 2008: Monsoons as eddy-mediated regime transitions of the tropical overturning circulation. Nat. Geosci., 1, 515–519, doi:10.1038/ngeo248.

    • Search Google Scholar
    • Export Citation

  • Brandefelt, J., and H. Körnich, 2008: Northern Hemisphere stationary waves in future climate projections. J. Climate, 21, 6341–6353, doi:10.1175/2008JCLI2373.1.

    • Search Google Scholar
    • Export Citation

  • Broccoli, A., and S. Manabe, 1992: The effects of orography on midlatitude Northern Hemisphere dry climates. J. Climate, 5, 1181–1201, doi:10.1175/1520-0442(1992)005<1181:TEOOOM>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Byrne, M. P., and P. A. O’Gorman, 2013: Link between land-ocean warming contrast and surface relative humidities in simulations with coupled climate models. Geophys. Res. Lett., 40, 5223–5227, doi:10.1002/grl.50971.

    • Search Google Scholar
    • Export Citation

  • Byrne, M. P., and P. A. O’Gorman, 2015: The response of precipitation minus evapotranspiration to climate warming: Why the “wet-get-wetter, dry-get-drier” scaling does not hold over land. J. Climate, 28, 8078–8092, doi:10.1175/JCLI-D-15-0369.1.

    • Search Google Scholar
    • Export Citation

  • Chadwick, R., I. Boutle, and G. Martin, 2013: Spatial patterns of precipitation change in CMIP5: Why the rich do not get richer in the tropics. J. Climate, 26, 3803–3822, doi:10.1175/JCLI-D-12-00543.1.

    • Search Google Scholar
    • Export Citation

  • Chen, J., and S. Bordoni, 2014: Orographic effects of the Tibetan Plateau on the East Asian summer monsoon: An energetic perspective. J. Climate, 27, 3052–3072, doi:10.1175/JCLI-D-13-00479.1.

    • Search Google Scholar
    • Export Citation

  • Chou, C., and J. D. Neelin, 2004: Mechanisms of global warming impacts on regional tropical precipitation. J. Climate, 17, 2688–2701, doi:10.1175/1520-0442(2004)017<2688:MOGWIO>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Frierson, D. M., 2007: The dynamics of idealized convection schemes and their effect on the zonally averaged tropical circulation. J. Atmos. Sci., 64, 1959–1976, doi:10.1175/JAS3935.1.

    • Search Google Scholar
    • Export Citation

  • Frierson, D. M., I. M. Held, and P. Zurita-Gotor, 2006: A gray-radiation aquaplanet moist GCM. Part I: Static stability and eddy scale. J. Atmos. Sci., 63, 2548–2566, doi:10.1175/JAS3753.1.

    • Search Google Scholar
    • Export Citation

  • Greve, P., B. Orlowsky, B. Mueller, J. Sheffield, M. Reichstein, and S. I. Seneviratne, 2014: Global assessment of trends in wetting and drying over land. Nat. Geosci., 7, 716–721, doi:10.1038/ngeo2247.

    • Search Google Scholar
    • Export Citation

  • Held, I. M., 1983: Stationary and quasi-stationary eddies in the extratropical troposphere: Theory. Large-Scale Dynamical Processes in the Atmosphere, B. Hoskins, Ed., Academic Press, 127–168.

  • Held, I. M., and M. Ting, 1990: Orographic versus thermal forcing of stationary waves: The importance of the mean low-level wind. J. Atmos. Sci., 47, 495–500, doi:10.1175/1520-0469(1990)047<0495:OVTFOS>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Held, I. M., and B. J. Soden, 2000: Water vapor feedback and global warming. Annu. Rev. Energy Environ., 25, 441–475, doi:10.1146/annurev.energy.25.1.441.

    • 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, 5686–5699, doi:10.1175/JCLI3990.1.

    • Search Google Scholar
    • Export Citation

  • Held, I. M., M. Ting, and H. Wang, 2002: Northern winter stationary waves: Theory and modeling. J. Climate, 15, 2125–2144, doi:10.1175/1520-0442(2002)015<2125:NWSWTA>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Hoskins, B. J., and D. J. Karoly, 1981: The steady linear response of a spherical atmosphere to thermal and orographic forcing. J. Atmos. Sci., 38, 1179–1196, doi:10.1175/1520-0469(1981)038<1179:TSLROA>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Knutson, T. R., and S. Manabe, 1995: Time-mean response over the tropical Pacific to increased CO2 in a coupled ocean–atmosphere model. J. Climate, 8, 2181–2199, doi:10.1175/1520-0442(1995)008<2181:TMROTT>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Levine, X. J., and T. Schneider, 2011: Response of the Hadley circulation to climate change in an aquaplanet GCM coupled to a simple representation of ocean heat transport. J. Atmos. Sci., 68, 769–783, doi:10.1175/2010JAS3553.1.

    • Search Google Scholar
    • Export Citation

  • Ma, J., S.-P. Xie, and Y. Kosaka, 2012: Mechanisms for tropical tropospheric circulation change in response to global warming. J. Climate, 25, 2979–2994, doi:10.1175/JCLI-D-11-00048.1.

    • Search Google Scholar
    • Export Citation

  • Merlis, T. M., and T. Schneider, 2011: Changes in zonal surface temperature gradients and Walker circulations in a wide range of climates. J. Climate, 24, 4757–4768, doi:10.1175/2011JCLI4042.1.

    • Search Google Scholar
    • Export Citation

  • Mitchell, J. F., C. Wilson, and W. Cunnington, 1987: On CO2 climate sensitivity and model dependence of results. Quart. J. Roy. Meteor. Soc., 113, 293–322, doi:10.1256/smsqj.47516.

    • Search Google Scholar
    • Export Citation

  • Molnar, P., W. R. Boos, and D. S. Battisti, 2010: Orographic controls on climate and paleoclimate of Asia: Thermal and mechanical roles for the Tibetan Plateau. Annu. Rev. Earth Planet. Sci., 38, 77–102, doi:10.1146/annurev-earth-040809-152456.

    • Search Google Scholar
    • Export Citation

  • Newman, M., G. N. Kiladis, K. M. Weickmann, F. M. Ralph, and P. D. Sardeshmukh, 2012: Relative contributions of synoptic and low-frequency eddies to time-mean atmospheric moisture transport, including the role of atmospheric rivers. J. Climate, 25, 7341–7361, doi:10.1175/JCLI-D-11-00665.1.

    • Search Google Scholar
    • Export Citation

  • O’Gorman, P. A., and T. Schneider, 2008: The hydrological cycle over a wide range of climates simulated with an idealized GCM. J. Climate, 21, 3815–3832, doi:10.1175/2007JCLI2065.1.

    • Search Google Scholar
    • Export Citation

  • Rodwell, M. J., and B. J. Hoskins, 1996: Monsoons and the dynamics of deserts. Quart. J. Roy. Meteor. Soc., 122, 1385–1404, doi:10.1002/qj.49712253408.

    • Search Google Scholar
    • Export Citation

  • Rodwell, M. J., and B. J. Hoskins, 2001: Subtropical anticyclones and summer monsoons. J. Climate, 14, 3192–3211, doi:10.1175/1520-0442(2001)014<3192:SAASM>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Sardeshmukh, P. D., and B. J. Hoskins, 1988: The generation of global rotational flow by steady idealized tropical divergence. J. Atmos. Sci., 45, 1228–1251, doi:10.1175/1520-0469(1988)045<1228:TGOGRF>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Schneider, T., P. A. O’Gorman, and X. J. Levine, 2010: Water vapor and the dynamics of climate changes. Rev. Geophys., 48, RG3001, doi:10.1029/2009RG000302.

    • Search Google Scholar
    • Export Citation

  • Seager, R., and Coauthors, 2007: Model projections of an imminent transition to a more arid climate in southwestern North America. Science, 316, 1181–1184, doi:10.1126/science.1139601.

    • Search Google Scholar
    • Export Citation

  • Seager, R., N. Naik, and G. A. Vecchi, 2010: Thermodynamic and dynamic mechanisms for large-scale changes in the hydrological cycle in response to global warming. J. Climate, 23, 4651–4668, doi:10.1175/2010JCLI3655.1.

    • Search Google Scholar
    • Export Citation

  • Seager, R., H. Liu, N. Henderson, I. Simpson, C. Kelley, T. Shaw, Y. Kushnir, and M. Ting, 2014a: Causes of increasing aridification of the Mediterranean region in response to rising greenhouse gases. J. Climate, 27, 4655–4676, doi:10.1175/JCLI-D-13-00446.1.

    • Search Google Scholar
    • Export Citation

  • Seager, R., and Coauthors, 2014b: Dynamical and thermodynamical causes of large-scale changes in the hydrological cycle over North America in response to global warming. J. Climate, 27, 7921–7948, doi:10.1175/JCLI-D-14-00153.1.

    • Search Google Scholar
    • Export Citation

  • Shaw, T. A., 2014: On the role of planetary-scale waves in the abrupt seasonal transition of the Northern Hemisphere general circulation. J. Atmos. Sci., 71, 1724–1746, doi:10.1175/JAS-D-13-0137.1.

    • Search Google Scholar
    • Export Citation

  • Shi, X., and D. R. Durran, 2014: The response of orographic precipitation over idealized midlatitude mountains due to global increases in CO2. J. Climate, 27, 3938–3956, doi:10.1175/JCLI-D-13-00460.1.

    • Search Google Scholar
    • Export Citation

  • Simpson, I. R., T. A. Shaw, and R. Seager, 2014: A diagnosis of the seasonally and longitudinally varying midlatitude circulation response to global warming. J. Atmos. Sci., 71, 2489–2515, doi:10.1175/JAS-D-13-0325.1.

    • Search Google Scholar
    • Export Citation

  • Simpson, I. R., R. Seager, M. Ting, and T. A. Shaw, 2016: Causes of change in Northern Hemisphere winter meridional winds and regional hydroclimate. Nat. Climate Change, 6, 65–70, doi:10.1038/nclimate2783.

    • Search Google Scholar
    • Export Citation

  • Stephenson, D. B., and I. M. Held, 1993: GCM response of northern winter stationary waves and storm tracks to increasing amounts of carbon dioxide. J. Climate, 6, 1859–1870, doi:10.1175/1520-0442(1993)006<1859:GRONWS>2.0.CO;2.

    • Search Google Scholar
    • Export Citation

  • Takahashi, K., and D. S. Battisti, 2007: Processes controlling the mean tropical Pacific precipitation pattern. Part II: The SPCZ and the southeast Pacific dry zone. J. Climate, 20, 5696–5706, doi:10.1175/2007JCLI1656.1.

    • Search Google Scholar
    • Export Citation

  • Vecchi, G. A., and B. J. Soden, 2007: Global warming and the weakening of the tropical circulation. J. Climate, 20, 4316–4340, doi:10.1175/JCLI4258.1.

    • 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, 73–76, doi:10.1038/nature04744.

    • Search Google Scholar
    • Export Citation

  • Voigt, A., and T. A. Shaw, 2015: Circulation response to warming shaped by radiative changes of clouds and water vapour. Nat. Geosci., 8, 102–106, doi:10.1038/ngeo2345.

    • Search Google Scholar
    • Export Citation

  • Wills, R. C., 2016: Stationary eddies and zonal variations of the global hydrological cycle in a changing climate. Ph.D. thesis, California Institute of Technology, 177 pp.

  • Wills, R. C., and T. Schneider, 2015: Stationary eddies and the zonal asymmetry of net precipitation and ocean freshwater forcing. J. Climate, 28, 5115–5133, doi:10.1175/JCLI-D-14-00573.1.

    • Search Google Scholar
    • Export Citation

  • Wu, Y., M. Ting, R. Seager, H.-P. Huang, and M. A. Cane, 2011: Changes in storm tracks and energy transports in a warmer climate simulated by the GFDL CM2.1 model. Climate Dyn., 37, 53–72, doi:10.1007/s00382-010-0776-4.

    • 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, 966–986, doi:10.1175/2009JCLI3329.1.

    • Search Google Scholar
    • Export Citation
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