The Gradient Genesis of Stratospheric Trace Species in the Subtropics and around the Polar Vortex

Kazuyuki Miyazaki Frontier Research Center for Global Change, Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan

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Toshiki Iwasaki Department of Geophysics, Graduate School of Science, Tohoku University, Sendai, Japan

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Abstract

Mechanisms that control the formation and decay of meridional gradients in stratospheric trace species in the subtropics and around the polar vortex are investigated using a gradient genesis equation that uses mass-weighted isentropic zonal means. Application of this method to global nitrous oxide (N2O) data output from a global chemical transport model shows that mean vertical transport increases the meridional tracer gradient from the subtropics to midlatitudes through the shearing deformation, particularly related to overturning of the Brewer–Dobson circulation. Mean meridional transport advects the subtropical tracer gradient toward midlatitudes, while the eddy stairstep effect, steepening at the edge of the well-mixed region because of a meridional gradient in the diffusion coefficient, increases the tracer gradient in the subtropics and around the polar vortex. Mechanisms controlling the evolution of the tracer gradients in the subtropics differ between spring and autumn. The autumnal subtropical tracer gradient maximum is generated mainly from shearing deformation of the mean vertical transport, but less from mean and eddy meridional fluxes. In spring, the eddy stairstep effect also contributes to the generation of the subtropical tracer gradient maximum. Strong divergence forces stretching deformation that causes the springtime subtropical tracer gradient to decay. The gradient genesis mechanism around the Antarctic polar vortex is significantly different from that in the subtropics. Development of the tracer gradient around the Antarctic polar vortex is mostly controlled by mean meridional stretching motion in the middle stratosphere. Vertical advection and eddy smoothing effects flatten the tracer gradient as the polar vortex decays.

Corresponding author address: Kazuyuki Miyazaki, Frontier Research Center for Global Change, Japan Agency for Marine-Earth Science and Technology, 3173-25 Showa-machi, Kanazawa-ku Yokohama, Kanagawa 236-0001, Japan. Email: kmiyazaki@jamstec.go.jp

Abstract

Mechanisms that control the formation and decay of meridional gradients in stratospheric trace species in the subtropics and around the polar vortex are investigated using a gradient genesis equation that uses mass-weighted isentropic zonal means. Application of this method to global nitrous oxide (N2O) data output from a global chemical transport model shows that mean vertical transport increases the meridional tracer gradient from the subtropics to midlatitudes through the shearing deformation, particularly related to overturning of the Brewer–Dobson circulation. Mean meridional transport advects the subtropical tracer gradient toward midlatitudes, while the eddy stairstep effect, steepening at the edge of the well-mixed region because of a meridional gradient in the diffusion coefficient, increases the tracer gradient in the subtropics and around the polar vortex. Mechanisms controlling the evolution of the tracer gradients in the subtropics differ between spring and autumn. The autumnal subtropical tracer gradient maximum is generated mainly from shearing deformation of the mean vertical transport, but less from mean and eddy meridional fluxes. In spring, the eddy stairstep effect also contributes to the generation of the subtropical tracer gradient maximum. Strong divergence forces stretching deformation that causes the springtime subtropical tracer gradient to decay. The gradient genesis mechanism around the Antarctic polar vortex is significantly different from that in the subtropics. Development of the tracer gradient around the Antarctic polar vortex is mostly controlled by mean meridional stretching motion in the middle stratosphere. Vertical advection and eddy smoothing effects flatten the tracer gradient as the polar vortex decays.

Corresponding author address: Kazuyuki Miyazaki, Frontier Research Center for Global Change, Japan Agency for Marine-Earth Science and Technology, 3173-25 Showa-machi, Kanazawa-ku Yokohama, Kanagawa 236-0001, Japan. Email: kmiyazaki@jamstec.go.jp

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  • Allen, D. R., and N. Nakamura, 2001: A seasonal climatology of effective diffusivity in the stratosphere. J. Geophys. Res., 106 , 79177936.

    • Search Google Scholar
    • Export Citation
  • Andrews, A. E., and Coauthors, 2001: Empirical age spectra for the midlatitude lower stratosphere from in situ observations of CO2: Quantitative evidence for a subtropical “barrier” to horizontal transport. J. Geophys. Res., 106 , 1025710274.

    • Search Google Scholar
    • Export Citation
  • Boering, K. A., B. C. Daube, S. C. Wofsy, M. Loewenstein, J. R. Podolske, and E. R. Keim, 1994: Tracer-tracer relationships and lower stratospheric dynamics: CO2 and N2O correlations during SPADE. Geophys. Res. Lett., 21 , 25672570.

    • Search Google Scholar
    • Export Citation
  • Boering, K. A., S. C. Wofsy, B. C. Daube, H. R. Schneider, M. Loewenstein, J. R. Podolske, and T. J. Conway, 1996: Stratospheric mean ages and transport rates from observations of carbon dioxide and nitrous oxide. Science, 274 , 13401343.

    • Search Google Scholar
    • Export Citation
  • Bowman, K. P., 1996: Rossby wave phase speeds and mixing barriers in the stratosphere. Part I: Observations. J. Atmos. Sci., 53 , 905916.

    • Search Google Scholar
    • Export Citation
  • Eluszkiewicz, J., R. S. Hemler, J. D. Mahlman, L. Bruhwiler, and L. L. Takacs, 2000: Sensitivity of age-of-air calculations to the choice of advection scheme. J. Atmos. Sci., 57 , 31853201.

    • Search Google Scholar
    • Export Citation
  • Gray, L. J., 2000: A model study of the influence of the quasi-biennial oscillation on trace gas distributions in the middle and upper stratosphere. J. Geophys. Res., 105 , 45394552.

    • Search Google Scholar
    • Export Citation
  • Gray, L. J., and J. M. Russell, 1999: Interannual variability of trace gases in the subtropical winter stratosphere. J. Atmos. Sci., 56 , 977993.

    • Search Google Scholar
    • Export Citation
  • Hall, T. M., and R. A. Plumb, 1994: Age as a diagnostic of stratospheric transport. J. Geophys. Res., 99 , 10591070.

  • Hasebe, F., 1983: Interannual variations of global total ozone revealed from Nimbus 4 BUV and ground-based observations. J. Geophys. Res., 88 , 68196834.

    • Search Google Scholar
    • Export Citation
  • Haynes, P., and E. Shuckburgh, 2000: Effective diffusivity as a diagnostic of atmospheric transport. 1. Stratosphere. J. Geophys. Res., 105 , 2277722794.

    • Search Google Scholar
    • Export Citation
  • Hitchman, M. H., M. McKay, and C. R. Trepte, 1994: A climatology of stratospheric aerosol. J. Geophys. Res., 99 , 2068920700.

  • Hoke, J. E., and R. A. Anthes, 1976: The initialization of numerical models by a dynamic-initialization technique. Mon. Wea. Rev., 104 , 15511556.

    • Search Google Scholar
    • Export Citation
  • Holton, J. R., 1981: An advective model for two-dimensional transport of stratospheric trace species. J. Geophys. Res., 86 , 1198911994.

    • Search Google Scholar
    • Export Citation
  • Hoskins, B. J., 1982: The mathematical theory of frontogenesis. Annu. Rev. Fluid Mech., 14 , 131151.

  • Iwasaki, T., 1989: A diagnostic formulation for wave-mean flow interactions and Lagrangian-mean circulation with a hybrid vertical coordinate of pressure and isentropes. J. Meteor. Soc. Japan, 67 , 293312.

    • Search Google Scholar
    • Export Citation
  • Jones, D. B. A., H. R. Schneider, and M. B. McElroy, 1998: Effects of the quasi-biennial oscillation on the zonally averaged transport of tracers. J. Geophys. Res., 103 , 1123511250.

    • Search Google Scholar
    • Export Citation
  • Jones, R. L., and J. A. Pyle, 1984: Observations of CH4 and N2O by the Nimbus 7 SAMS—A comparison with in situ data and two-dimensional numerical model calculations. J. Geophys. Res., 89 , 52635279.

    • Search Google Scholar
    • Export Citation
  • Jost, H-J., and Coauthors, 2002: Mixing events revealed by anomalous tracer relationships in the Arctic vortex during winter 1999/2000. J. Geophys. Res., 107 .4795, doi:10.1029/2002JD002380.

    • Search Google Scholar
    • Export Citation
  • Juckes, M. N., and M. E. McIntyre, 1987: A high-resolution one-layer model of breaking planetary waves in the stratosphere. Nature, 328 , 590596.

    • Search Google Scholar
    • Export Citation
  • Luo, M., R. J. Cicerone, J. M. Russell III, and T. Y. W. Huang, 1994: Observations of stratospheric hydrogen fluoride by halogen occultation experiment (HALOE). J. Geophys. Res., 99 , 1669116706.

    • Search Google Scholar
    • Export Citation
  • McIntyre, M. E., and T. N. Palmer, 1983: Breaking planetary waves in the stratosphere. Nature, 305 , 593600.

  • McIntyre, M. E., and T. N. Palmer, 1984: The “surf zone” in the stratosphere. J. Atmos. Terr. Phys., 46 , 825850.

  • Miyazaki, K., and T. Iwasaki, 2005: Diagnosis of meridional ozone transport based on mass-weighted isentropic zonal means. J. Atmos. Sci., 62 , 11921208.

    • Search Google Scholar
    • Export Citation
  • Miyazaki, K., T. Iwasaki, K. Shibata, and M. Deushi, 2005a: Roles of transport in the seasonal variation of the total ozone amount. J. Geophys. Res., 110 .D18309, doi:10.1029/2005JD005900.

    • Search Google Scholar
    • Export Citation
  • Miyazaki, K., T. Iwasaki, K. Shibata, M. Deushi, and T. Sekiyama, 2005b: The impact of changing meteorological variables to be assimilated into GCM on ozone simulation with MRI CTM. J. Meteor. Soc. Japan, 83 , 909918.

    • Search Google Scholar
    • Export Citation
  • Morgenstern, O., J. A. Pyle, A. M. Iwi, W. A. Norton, J. W. Elkins, D. F. Hurst, and P. A. Romashkin, 2002: Diagnosis of mixing between middle latitudes and the polar vortex from tracer-tracer correlations. J. Geophys. Res., 107 .4321, doi:10.1029/2001JD001224.

    • Search Google Scholar
    • Export Citation
  • Mote, P. W., and Coauthors, 1996: An atmospheric tape recorder: The imprint of tropical tropopause temperatures on stratospheric water vapor. J. Geophys. Res., 101 , 39894006.

    • Search Google Scholar
    • Export Citation
  • Nakamura, N., and J. Ma, 1997: Modified Lagrangian-mean diagnostics of the stratospheric polar vortices: 2. Nitrous oxide and seasonal barrier migration in the cryogenic limb array etalon spectrometer and SKYHI general circulation model. J. Geophys. Res., 102 , 2572125736.

    • Search Google Scholar
    • Export Citation
  • Neu, J. L., L. C. Sparling, and R. A. Plumb, 2003: Variability of the subtropical “edges” in the stratosphere. J. Geophys. Res., 108 .4482, doi:10.1029/2002JD002706.

    • Search Google Scholar
    • Export Citation
  • Niwano, M., and M. Shiotani, 2001: Quasi-biennial oscillation in vertical velocity inferred from trace gas data in the equatorial lower stratosphere. J. Geophys. Res., 106 , 72817290.

    • Search Google Scholar
    • Export Citation
  • Niwano, M., K. Yamazaki, and M. Shiotani, 2003: Seasonal and QBO variations of ascent rate in the tropical lower stratosphere as inferred from UARS HALOE trace gas data. J. Geophys. Res., 108 .4794, doi:10.1029/2003JD003871.

    • Search Google Scholar
    • Export Citation
  • Plumb, R. A., 2002: Stratospheric transport. J. Meteor. Soc. Japan, 80 , 793809.

  • Plumb, R. A., 2007: Tracer interrelationships in the stratosphere. Rev. Geophys., in press.

  • Plumb, R. A., and M. K. W. Ko, 1992: Interrelationships between mixing ratios of long-lived stratospheric constituents. J. Geophys. Res., 97 , 1014510156.

    • Search Google Scholar
    • Export Citation
  • Plumb, R. A., D. W. Waugh, and M. P. Chipperfield, 2000: The effects of mixing on tracer relationships in the polar vortices. J. Geophys. Res., 105 , 1004710062.

    • Search Google Scholar
    • Export Citation
  • Polvani, L. M., D. W. Waugh, and R. A. Plumb, 1995: On the subtropical edge of the stratospheric surf zone. J. Atmos. Sci., 52 , 12881309.

    • Search Google Scholar
    • Export Citation
  • Randel, W. J., J. Gille, A. E. Roche, J. Kumer, J. L. Mergenthaler, J. W. Waters, E. F. Fishbein, and W. Lahoz, 1993: Stratospheric transport from the tropics to middle latitudes by planetary wave mixing. Nature, 365 , 533535.

    • Search Google Scholar
    • Export Citation
  • Randel, W. J., B. A. Boville, J. C. Gille, P. L. Bailey, S. T. Massie, J. B. Kumer, J. L. Mergenthaler, and A. E. Roche, 1994: Simulation of stratospheric N2O in the NCAR CCM2: Comparison with CLAES data and global budget analyses. J. Atmos. Sci., 51 , 28342845.

    • Search Google Scholar
    • Export Citation
  • Randel, W. J., F. Wu, J. M. Russell III, A. Roche, and J. Waters, 1998: Seasonal cycles and QBO variations in stratospheric CH4 and H2O observed in VARS HALOE data. J. Atmos. Sci., 55 , 163185.

    • Search Google Scholar
    • Export Citation
  • Rosenlof, K. H., 1995: Seasonal cycle of the residual mean meridional circulation in the stratosphere. J. Geophys. Res., 100 , 51735192.

    • Search Google Scholar
    • Export Citation
  • Russell III, J. M., and Coauthors, 1993: The Halogen Occultation Experiment. J. Geophys. Res., 98 , 1077710797.

  • Shibata, K., H. Yoshimura, M. Ohizumi, M. Hosaka, and M. Sugi, 1999: A simulation of troposphere, stratosphere and mesosphere with an MRI/JMA 98 GCM. Pap. Meteor. Geophys., 50 , 1553.

    • Search Google Scholar
    • Export Citation
  • Shibata, K., M. Deushi, T. Sekiyama, and H. Yoshimura, 2005: Development of an MRI chemical transport model for the study of stratospheric chemistry. Pap. Meteor. Geophys., 55 , 75119.

    • Search Google Scholar
    • Export Citation
  • Shuckburgh, E., W. Norton, A. Iwi, and P. Haynes, 2001: Influence of the quasi-biennial oscillation on isentropic transport and mixing in the tropics and subtropics. J. Geophys. Res., 106 , 1432714338.

    • Search Google Scholar
    • Export Citation
  • Simmons, A. J., and J. K. Gibson, 2000: The ERA-40 project plan. ERA-40 Project Report Series 1, ECMWF, Reading, United Kingdom, 63 pp.

  • Trepte, C. R., and M. H. Hitchman, 1992: Tropical stratospheric circulation deduced from satellite aerosol data. Nature, 355 , 626628.

    • Search Google Scholar
    • Export Citation
  • Volk, C. M., and Coauthors, 1996: Quantifying transport between the tropical and mid-latitude lower stratosphere. Science, 272 , 17631768.

    • Search Google Scholar
    • Export Citation
  • Wagner, R. E., and K. P. Bowman, 2000: Wavebreaking and mixing in the Northern Hemisphere summer stratosphere. J. Geophys. Res., 105 , 2479924808.

    • Search Google Scholar
    • Export Citation
  • Waugh, D. W., 1993: Subtropical stratospheric mixing linked to disturbances in the polar vortices. Nature, 365 , 535537.

  • Waugh, D. W., 1996: Seasonal variation of isentropic transport out of the tropical stratosphere. J. Geophys. Res., 101 , 40074024.

  • Waugh, D. W., and Coauthors, 1997: Mixing of polar vortex air into middle latitudes as revealed by tracer-tracer scatterplots. J. Geophys. Res., 102 , 1311913134.

    • Search Google Scholar
    • Export Citation
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