Documentation on the differences between ECMWF and NCEP version
---------------------------------------------------------------

1. Changes were made in the following files

   programs to read in the data
     - gridcheck.f
     - readwind.f
   coordinate transformation
     - verttransform.f
   convection scheme
     - convmix.f
     - calcmatrix.f
   boundary layer parameterization
     - richardson.f
     - obukhov.f
     - pbl_profile.f
     - calcpar.f
   PV calculation
     - calcpv.f
   includefiles
     - includecom
     - includepar

2. The NCEP GFS data are given on pressure levels. Those pressure levels
   that lie below topography are not used, i.e. only those
   levels that have a pressure lower than that at the surface are
   used for the coordinate transformation to FLEXPART z-levels

3. Note that in the ECMWF version convection is calculated
   on the original ECMWF etz-levels. In the NCEP GFS version convection
   is calculated on the FLEXPART z-levels

4. So far no NCEP GFS nested data are available. The current NCEP GFS
   FLEXPART version cannot be operated with nested data.
   To operate the NCEP GFS version with nested data,
   the following files must be adjusted
      - gridcheck_nests.f
      - readwind_nests.f
      - verttransform_nests.f
      - convmix.f
      - calcpar_nests.f
      - calcpv_nests.f
      

