To compile:

1) create symlink to Makefile.conf for your platform (zeus, jet or wcoss). For example, on zeus
   ln -fs Makefile.conf.zeus Makefile.conf

2) make sure the relevant modules are loaded on zeus, i.e.

   module load intel
   module load netcdf
   module load mpt 

3) To compile global_enkf (for GFS model), edit Makefile.conf and make sure the lines

  FFLAGS_F90    = -DGFS
  EXE_FILE = global_enkf

  are uncommented, and 

  #FFLAGS_F90    = -DWRF
  #EXE_FILE = regional_enkf

  are commented out.

4) To compile regional enkf (for WRF model), edit Makefile.conf and make sure the lines

  FFLAGS_F90    = -DWRF
  EXE_FILE = wrf_enkf

  are uncommented, and 

  #FFLAGS_F90    = -DGFS
  #EXE_FILE = global_enkf

  are commented out.

5) To compile enkf for NMMB model, edit Makefile.conf and make sure the lines

  FFLAGS_F90    = -DNMMB
  EXE_FILE = nmmb_enkf

  are uncommented, and 

  #FFLAGS_F90    = -DGFS
  #EXE_FILE = global_enkf

  are commented out.

6) make clean; make

Some import namelist variables:

use_gfs_nemsio (logical):  Use nemsio instead of spectral files for GFS (default .false.)
regional (logical): replaces old variable 'wrf_regional'.  Use regional model instead of GFS or NMMB. Default .false.
nmmb (logical): Use nmmb model (either global or regional). Default .false. 
arw (logical): Use wrf-arw model if regional=.true.  Default .false.
nmm (logibal):  Use nmm core (HWRF) if regional=.true.  Default .true.

See the comments in params.f90 for other namelist variable definitions.
