• transform the T159 spherical harmonics grids to other spherical harmonic grids, reduced and regular gaussian grids and uniform latitude-longitude grids.
• interpolate the reduced and regular N80 grids to other regular gaussian grids and uniform latitude-longitude grids.
• interpolate the uniform 2.5^o latitude-longitude grids to other uniform latitude-longitude grids and regular gaussian grids.

These FORTRAN programs are available here. The programs use the ECMWF's EMOSLIB/GRIBEX software library. The ECMWF library is distributed under the same condition as the ERA-40 data. Please review the conditions. Improved software is under development. Before this software is made available, all users should be aware of the following:

• The library has been loaded on several local NCAR computers. For more information, click here.

• The library package has 2 parts. The GRIBEX portion primarily decodes GRIB records. The EMOSLIB portion performs spectral grtid transformations and interpolations for the grid-point data.

• The current library version is 000263 (as of 11/2004). Tests have revealed problems with the spectral transformations to gaussian grids for scalar quantities and the transformation of the divergence and vorticity to U and V wind components on ANY grid. More information on the wind problem can be found here

• Our analysis indicates that library version 000260 is a better compromise. This version appears to be performing the transformations of specrtal scalar fields correctly. However, this version also DOES NOT correctly transform the divergence and vorticity to U and V. At this time, we do not have an ECMWF library which accurately computes the U and V wind components. We have prototype methods to overcome this problem. These use the NCAR Spherepack library in combination with the EMOSLIB library. Please contact Joey Comeaux if you need the U and V.