SURGERY : to determine a gaussian reduced grid (1999)

This procedure "surgery" is determining the number of longitudes for each latitude of a gaussian reduced grid, defined by :

• the number of latitudes NDGL,
• the maximum number of longitudes NDLON,
• the truncation NSMAX.

The job is split in 2 parts :

• first part is the computation of the Legendre polynomials onto a file (done by Arpege/128 bits)
• second part is the computation of the reduced grid, after reading the Legendre polynomials file (done by a specific program, adapted from the subroutine surgri.F)

How to use it :

• 1/ Copy the following file on VPP : mrpm602/rgrid/surgery and set your favourite values for NDGL, NDLON, NSMAX (Beware : set the nominal truncation, not twice its value : the procedure is doing by itself the multiplication by 2 !) Remark : this procedure works for quadratic grids ; if you are using non-quadratic grid, you should set for NSMAX the equivalent truncation you would have for a quadratic grid.
• 2/ Submit the script
• 3/ Enjoy the result on the *.o* file
• 4/ ALWAYS congratulate or damn the builder at email adress ryad.elkhatib@meteo.fr

More about it ?

Then explore the directory mrpm602/rgrid on VPP, everything is public !