anchor.diff:    ! Main input files
     character(30) :: initUfile, initVfile, initHfile, initEtaFile
     character(30) :: zonalWindFile, meridionalWindFile
  +  
  +  ! External pressure solver variables
  +  ! except for the logical switch, none of these are used
  +  ! unless the external solver is used.
  +  logical :: useExternalSolver
  +  integer :: nProcX, nProcY
  +
  +  integer :: mpi_comm
  +
  +  integer*8 :: parcsr_A
  +  integer*8 :: A
  +  integer*8 :: b
  +  integer*8 :: x
  +  integer*8 :: par_b
  +  integer*8 :: par_x
  +  integer*8 :: solver
  +  integer*8 :: precond
   
     ! Set default values here
   
  
positive.code:   read(unit=8, nml=GRID)
    read(unit=8, nml=INITIAL_CONDITONS)
    read(unit=8, nml=EXTERNAL_FORCING)
    close(unit=8)
  
    allocate(h(0:nx+1, 0:ny+1, layers))
    allocate(u(0:nx+1, 0:ny+1, layers))
  
negative.code: 
    namelist /EXTERNAL_FORCING/ zonalWindFile, meridionalWindFile, &
        DumpWind, wind_mag_time_series_file
  
    namelist /PRESSURE_SOLVER/ useExternalSolver, nProcX, nProcY
  
    open(unit=8, file="parameters.in", status='OLD', recl=80)
    read(unit=8, nml=NUMERICS)
  