Planetary and Gravity Waves in a Polar Basin

Andrew J. Willmott Newcastle University, Newcastle upon Tyne, United Kingdom

Search for other papers by Andrew J. Willmott in
Current site
Google Scholar
PubMed
Close
and
Estanislao Gavilan Pascual-Ahuir Newcastle University, Newcastle upon Tyne, United Kingdom

Search for other papers by Estanislao Gavilan Pascual-Ahuir in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

The eigenfrequencies of freely propagating barotropic, divergent, planetary waves and gravity waves in a spherical polar cap are presented using an approximation in which full spherical geometry is retained in the derivation of the wave amplitude equation. Subsequently, the colatitude angle in the coefficients of the wave amplitude equation is fixed, thereby allowing the eigenvalue problem to be solved using analytical methods. The planetary wave frequencies are compared with published results that adopt the polar-plane approximation to solve the equivalent free-wave problem. Low-order planetary wave frequencies calculated in this study agree well with the polar-plane approximation results. The sensitivity of the wave frequencies to the choice of the fixed colatitude in the coefficients of the wave amplitude equation is discussed.

© 2017 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Andrew J. Willmott, andrew.willmott@newcastle.ac.uk

Abstract

The eigenfrequencies of freely propagating barotropic, divergent, planetary waves and gravity waves in a spherical polar cap are presented using an approximation in which full spherical geometry is retained in the derivation of the wave amplitude equation. Subsequently, the colatitude angle in the coefficients of the wave amplitude equation is fixed, thereby allowing the eigenvalue problem to be solved using analytical methods. The planetary wave frequencies are compared with published results that adopt the polar-plane approximation to solve the equivalent free-wave problem. Low-order planetary wave frequencies calculated in this study agree well with the polar-plane approximation results. The sensitivity of the wave frequencies to the choice of the fixed colatitude in the coefficients of the wave amplitude equation is discussed.

© 2017 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Andrew J. Willmott, andrew.willmott@newcastle.ac.uk
Save
  • Abramowitz, M., and I. A. Stegun, Eds., 1965: Handbook of Mathematical Functions. Dover Publications, 1046 pp.

  • Bridger, A. F. C., and D. E. Stevens, 1980: Long atmospheric waves and the polar-plane approximation to the Earth’s spherical geometry. J. Atmos. Sci., 37, 534544, doi:10.1175/1520-0469(1980)037<0534:LAWATP>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Harlander, U., 2005: A high-latitude quasi-geostrophic delta plane model derived from spherical geometry. Tellus, 57A, 4354, doi:10.3402/tellusa.v57i1.14601.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Haurwitz, B., 1975: Long circumpolar atmospheric waves. Arch. Meteor. Geophys. Bioklimatol., 24A, 118, doi:10.1007/BF02247554.

  • Imawaki, S., and K. Takano, 1974: Planetary flow in a circular basin. Deep-Sea Res. Oceanogr. Abstr., 21, 6976, doi:10.1016/0011-7471(74)90020-5.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Kitauchi, H., and M. Ikeda, 2009: An analytic solution of steady Stokes flow on a rotating polar cap. Fluid Dyn. Res., 41, 045505, doi:10.1088/0169-5983/41/4/045505.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • LeBlond, P. H., 1964: Planetary waves in a symmetrical polar basin. Tellus, 16, 503512, doi:10.3402/tellusa.v16i4.8989.

  • Longuet-Higgins, M. S., 1968: The eigenfunctions of Laplace’s tidal equations over a sphere. Philos. Trans. Roy. Soc. London, A262, 511607, doi:10.1098/rsta.1968.0003.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Paldor, N., 2015: Shallow Water Waves on the Rotating Earth. Springer, 77 pp.

    • Crossref
    • Export Citation
  • Paldor, N., Y. De-Leon, and O. Shamir, 2013: Planetary (Rossby) waves and inertia–gravity (Poincaré) waves in a barotropic ocean over a sphere. J. Fluid Mech., 726, 123136, doi:10.1017/jfm.2013.219.

    • Crossref
    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 242 60 7
PDF Downloads 95 29 3