Comparative Analysis of Conformal Mappings Used in Limited-Area Models of Numerical Weather Prediction

Andrei Bourchtein Department of Mathematics, Pelotas State University, Pelotas, Brazil

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Ludmila Bourchtein Department of Mathematics, Pelotas State University, Pelotas, Brazil

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Abstract

Conformal separable projections from a sphere onto a plane are introduced to generalize the concept of conformal stereographic, conic, and cylindrical projections. The concept of equivalence of projections is used for partition of all considered projections into equivalence classes. The variation coefficient is defined as the ratio between maximum and minimum mesh sizes of numerical grids. The problem of minimization of this coefficient inside each equivalence class is studied. The obtained variation coefficients from all classes are compared and the principal relation among stereographic, cylindrical, and conic projections is established. The stereographic conformal projection is indicated as that which generates the “best” numerical grids for numerical weather prediction limited-area models.

Corresponding author address: Dr. Andrei Bourchtein, Rua Anchieta 4715 bloco K, Ap. 304, 96020-250 Pelotas, Brazil. Email: burstein@terra.com.br

Abstract

Conformal separable projections from a sphere onto a plane are introduced to generalize the concept of conformal stereographic, conic, and cylindrical projections. The concept of equivalence of projections is used for partition of all considered projections into equivalence classes. The variation coefficient is defined as the ratio between maximum and minimum mesh sizes of numerical grids. The problem of minimization of this coefficient inside each equivalence class is studied. The obtained variation coefficients from all classes are compared and the principal relation among stereographic, cylindrical, and conic projections is established. The stereographic conformal projection is indicated as that which generates the “best” numerical grids for numerical weather prediction limited-area models.

Corresponding author address: Dr. Andrei Bourchtein, Rua Anchieta 4715 bloco K, Ap. 304, 96020-250 Pelotas, Brazil. Email: burstein@terra.com.br

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  • Bates, J. R., S. Moorthi, and R. W. Higgins, 1993: A global multilevel atmospheric model using a vector semi-Lagrangian finite-difference scheme. Part I: Adiabatic formulation. Mon. Wea. Rev., 121 , 244263.

    • Search Google Scholar
    • Export Citation
  • Côté, J., S. Gravel, A. Methot, A. Patoine, M. Roch, and A. Staniforth, 1998: The operational CMC–MRB global environmental multiscale (GEM) model. Part I: Design considerations and formulation. Mon. Wea. Rev., 126 , 13731395.

    • Search Google Scholar
    • Export Citation
  • Durran, D. R., 1999: Numerical Methods for Wave Equations in Geophysical Fluid Dynamics. Springer-Verlag, 465 pp.

  • Glahn, H. R., 1988: Characteristics of map projections and implications for AWIPS-90. TDL Office Note 88-5, National Weather Service, NOAA, 45 pp.

    • Search Google Scholar
    • Export Citation
  • Glahn, H. R., 1990: The equivalency of the tangent and secant Lambert conformal map projections. Mon. Wea. Rev., 118 , 27812783.

  • McDonald, A., and J. R. Bates, 1989: Semi-Lagrangian integration of a gridpoint shallow water model on the sphere. Mon. Wea. Rev., 117 , 130137.

    • Search Google Scholar
    • Export Citation
  • McDonald, A., and J. E. Haugen, 1992: A two time-level, three-dimensional semi-Lagrangian, semi-implicit, limited-area, grid-point model of the primitive equations. Mon. Wea. Rev., 120 , 26032621.

    • Search Google Scholar
    • Export Citation
  • Mesinger, F., and A. Arakawa, 1976: Numerical methods used in atmospheric models. GARP Publication Series, Vol. 1, No. 17, WMO-ICSU, 64 pp.

    • Search Google Scholar
    • Export Citation
  • Mesinger, F., S. Nickovic, D. Gavrilov, and D. G. Deaven, 1988: The step-mountain coordinate: Model description and performance for cases of Alpine lee cyclogenesis and for a case of Appalachian redevelopment. Mon. Wea. Rev., 116 , 14931507.

    • Search Google Scholar
    • Export Citation
  • Pearson II, F., 1990: Map Projections: Theory and Applications. CRC Press, 371 pp.

  • Pudykiewicz, J., R. Benoit, and A. Staniforth, 1985: Preliminary results from a partial LRTAP model based on an existing meteorological forecast model. Atmos.–Ocean, 23 , 267303.

    • Search Google Scholar
    • Export Citation
  • Snyder, J. P., 1993: Flattening the Earth: Two Thousand Years of Map Projections. University of Chicago Press, 365 pp.

  • Staniforth, A., 1997: Regional modeling: A theoretical discussion. Meteor. Atmos. Phys., 63 , 1529.

  • Staniforth, A., and J. Côté, 1991: Semi-Lagrangian integration schemes for atmospheric models—A review. Mon. Wea. Rev., 119 , 22062223.

    • Search Google Scholar
    • Export Citation
  • Thompson, J. F., Z. U. A. Warsi, and C. W. Mastin, 1985: Numerical Grid Generation. North-Holland, 483 pp.

  • Williamson, D. L., 1979: Difference approximations for numerical weather prediction over a sphere. GARP Publication Series, Vol. 2, No. 17, WMO-ICSU, 487 pp.

    • Search Google Scholar
    • Export Citation
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