Gaussian grid

File:NCEP T62 gaussian grid.png

NCEP T62 Gaussian grid points

A Gaussian grid is used in the earth sciences as a gridded horizontal coordinate system for scientific modeling on a sphere (i.e., the approximate shape of the Earth). The grid is rectangular, with a set number of orthogonal coordinates (usually latitude and longitude).

The gridpoints along the longitudes are equally spaced, while they are unequally spaced along the latitudes, where they are defined by their Gaussian quadrature. There are no grid points at the poles.

In a regular Gaussian grid, the number of gridpoints along the longitudes is constant, usually double the number along the latitudes.

In a reduced (or thinned) Gaussian grid, the number of gridpoints in the rows decreases towards the poles, which keeps the gridpoint separation approximately constant across the sphere.

Examples of Gaussian grids

• CCCma global climate models of climate change
  • 96×48
  • 128×64
• European Centre for Medium-Range Weather Forecasts [1]
  • N48 – 192×96
  • N80 – 320×160
  • N128 – 512×256
  • N160 – 640×320
  • N200 – 800×400
  • N256 – 1024×512
  • N400 – 1600×800
  • N512 – 2048×1024
  • N640 – 2560×1280

See also

• Global climate model
• Spectral method
• Spherical harmonics

References

• NCAR Command Language documentation
• W.M. Washington and C.L. Parkinson, 2005. An Introduction to Three-Dimensional Climate Modeling. Sausalito, CA, University Science Books. 368 pp.ru:Гауссовская сетка