Constraints on wave drag parameterization schemes for simulating the quasi-biennial oscillation. Part I: gravity wave forcing

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Campbell, Lucy J. ; Shepherd, Theodore G. (2005)
  • Publisher: American Meteorological Society
  • Related identifiers: doi: 10.1175/JAS3616.1
  • Subject:
    arxiv: Physics::Atmospheric and Oceanic Physics | Astrophysics::Earth and Planetary Astrophysics | Physics::Space Physics | Astrophysics::Solar and Stellar Astrophysics

Parameterization schemes for the drag due to atmospheric gravity waves are discussed and compared in the context of a simple one-dimensional model of the quasi-biennial oscillation (QBO). A number of fundamental issues are examined in detail, with the goal of providing a better understanding of the mechanism by which gravity wave drag can produce an equatorial zonal wind oscillation. The gravity wave–driven QBOs are compared with those obtained from a parameterization of equatorial planetary waves. In all gravity wave cases, it is seen that the inclusion of vertical diffusion is crucial for the descent of the shear zones and the development of the QBO. An important difference between the schemes for the two types of waves is that in the case of equatorial planetary waves, vertical diffusion is needed only at the lowest levels, while for the gravity wave drag schemes it must be included at all levels. The question of whether there is downward propagation of influence in the simulated QBOs is addressed. In the gravity wave drag schemes, the evolution of the wind at a given level depends on the wind above, as well as on the wind below. This is in contrast to the parameterization for the equatorial planetary waves in which there is downward propagation of phase only. The stability of a zero-wind initial state is examined, and it is determined that a small perturbation to such a state will amplify with time to the extent that a zonal wind oscillation is permitted.
  • References (27)
    27 references, page 1 of 3

    Alexander, M. J., and T. J. Dunkerton, 1999: A spectral parameterization of mean-flow forcing due to breaking gravity waves. J. Atmos. Sci., 56, 4167-4182.

    Andrews, D. G., J. R. Holton, and C. B. Leovy, 1987: Middle Atmosphere Dynamics. Academic Press, 489 pp.

    Baldwin, M. P., and Coauthors, 2001: The quasi-biennial oscillation. Rev. Geophys., 39, 179-229.

    Booker, J. R., and F. P. Bretherton, 1967: The critical level for gravity waves in a shear flow. J. Fluid Mech., 27, 513-539.

    Campbell, L. J., and T. G. Shepherd, 2005: Constraints on wave drag parameterization schemes for simulating the quasibiennial oscillation. Part II: Combined effects of gravity waves and equatorial planetary waves. J. Atmos. Sci., 62, 4196-4205.

    Dunkerton, T. J., 1981a: Wave transience in a compressible atmosphere. Part I: Transient internal wave, mean-flow interaction. J. Atmos. Sci., 38, 281-297.

    --, 1981b: Wave transience in a compressible atmosphere. Part II: Transient equatorial waves in the quasi-biennial oscillation. J. Atmos. Sci., 38, 298-307.

    --, 1982: Wave transience in a compressible atmosphere. Part III: The saturation of internal gravity waves in the mesosphere. J. Atmos. Sci., 39, 1042-1051.

    --, 1991: Nonlinear propagation of zonal winds in an atmosphere with Newtonian cooling and equatorial wavedriving. J. Atmos. Sci., 48, 236-263.

    --, 1997: The role of gravity waves in the quasi-biennial oscillation. J. Geophys. Res., 102, 26 053-26 076.

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