Gauss2lats

Estimates the latitudes of a Gaussian grid.

Description

Spectral atmospheric models provide data on a Gaussian grid that has regular longitude spacing but irregular latitude spacing. Gauss2lats provides the latitudes for such data. This information is needed, for example, when making a contour map.

The function determines the Gaussian latitudes by finding the roots of the ordinary Legendre polynomial of degree NLAT using Newton's iteration method. The only input required is the number of latitude lines in the Gaussian grid. The outputs are Gaussian latitudes, latitude spacing, and cosine of latitude.

• MATLAB release: MATLAB 6.1 (R12.1)
• Other requirements: The code has been tested and runs satisfactorily on an IBM PC and G4 Mac. Compares to within 13 decimal places of results from a Cray J90.