SPAWNING

The SPAWNING program performs horizontal interpolation from one Meso-NH file (file 1) to another (file 2). The grid of file 2 must be entirely contained within the grid of file 1. While file 2 can be used directly for a model run, its surface fields especially orography are smoothed. However, the model can still be run with both files using grid nesting, as an iterative procedure ensures the nesting condition for orography is met. The domain of file 2 can be defined in two ways:

  • By specifying the parameters in the namelist NAM_GRID2_SPA.

  • By using the domain of another Meso-NH file with a grid that is coherent with the input file. For example, this could be a PGD file generated by PREP_PGD, where the domain is derived from file 1 and uses the same specifications as those in NAM_GRID2_SPA.

Warning

  • When you want to force Meso-NH by Meso-NH you cannot create an independent grid at that time, the horizontal grids must be consistent.

  • Vertical grid can be changed when you force Meso-NH by an other Meso-NH simulation, without grid nesting.

SPAWNING program and its corresponding namelist and function

Executable

Namelist

Function

SPAWNING

SPAWN1.nam

Horizontal interpolations from a Meso-NH file into another Meso-NH file, with a finer resolution and smaller domain.

The following namelists can be used in the SPAWN1.nam file :

NAM_BLANKn

NAM_BLANKn content

Fortran name

Fortran type

Default value

XDUMMY1

REAL

0.0

XDUMMY2

REAL

0.0

XDUMMY3

REAL

0.0

XDUMMY4

REAL

0.0

XDUMMY5

REAL

0.0

XDUMMY6

REAL

0.0

XDUMMY7

REAL

0.0

XDUMMY8

REAL

0.0

NDUMMY1

INTEGER

0

NDUMMY2

INTEGER

0

NDUMMY3

INTEGER

0

NDUMMY4

INTEGER

0

NDUMMY5

INTEGER

0

NDUMMY6

INTEGER

0

NDUMMY7

INTEGER

0

NDUMMY8

INTEGER

0

LDUMMY1

LOGICAL

TRUE

LDUMMY2

LOGICAL

TRUE

LDUMMY3

LOGICAL

TRUE

LDUMMY4

LOGICAL

TRUE

LDUMMY5

LOGICAL

TRUE

LDUMMY6

LOGICAL

TRUE

LDUMMY7

LOGICAL

TRUE

LDUMMY8

LOGICAL

TRUE

CDUMMY1

CHARACTER(LEN=80)

CDUMMY2

CHARACTER(LEN=80)

CDUMMY3

CHARACTER(LEN=80)

CDUMMY4

CHARACTER(LEN=80)

CDUMMY5

CHARACTER(LEN=80)

CDUMMY6

CHARACTER(LEN=80)

CDUMMY7

CHARACTER(LEN=80)

CDUMMY8

CHARACTER(LEN=80)

Eight dummy variables and arrays (real, integer, logical, and character of length 80) are defined for testing and debugging. They are read through the namelist but are not used by any Meso-NH routine. If a developer wants to temporarily add a parameter to a subroutine, they can include a USE MODD_BLANK_n statement in that subroutine. This allows them to access and modify these variables via the namelist input.

NAM_GRID2_SPA

NAM_GRID2_SPA content

Fortran name

Fortran type

Default value

IXOR

INTEGER

1

IYOR

INTEGER

1

IXSIZE

INTEGER

file 1 domain

IYSIZE

INTEGER

file 1 domain

IDXRATIO

INTEGER

1

IDYRATIO

INTEGER

1

GBAL_ONLY

INTEGER

.FALSE.

  • IXOR : first point I index, according to the file 1 grid, left to and out of the new physical domain.

  • IYOR : first point J index, according to the file 1 grid, under and out of the new physical domain.

  • IXSIZE : number of grid points in I direction, according to file 1 grid, recovered by the new domain. It must be equal to \(2^m \times 3^n \times 5^p\) with \((m,n,p) \ge 0\)

  • IYSIZE : number of grid points in J direction, according to file 1 grid, recovered by the new domain. It must be equal to \(2^m \times 3^n \times 5^p\) with \((m,n,p) \ge 0\)

  • IDXRATIO : resolution factor in I direction between the file 1 grid and the new grid. It must be equal to \(2^m \times 3^n \times 5^p\) with \((m,n,p) \ge 0\)

  • IDYRATIO : resolution factor in J direction between the file 1 grid and the new grid. It must be equal to \(2^m \times 3^n \times 5^p\) with \((m,n,p) \ge 0\)

  • GBAL_ONLY : flag to enforce anelastic constraint only. The spawned file have the same characteristics as the CINIFILE one.

NAM_LUNIT2_SPA

NAM_LUNIT2_SPA content

Fortran name

Fortran type

Default value

CINIFILE

CHARACTER(LEN=128)

‘INIFILE’

CINIFILEPGD

CHARACTER(LEN=128)

YDOMAIN

CHARACTER(LEN=128)

YSPAFILE

CHARACTER(LEN=128)

YSPANBR

CHARACTER(LEN=2)

‘00’

YDADINIFILE

CHARACTER(LEN=128)

YDADSPAFILE

CHARACTER(LEN=128)

YSONFILE

CHARACTER(LEN=128)

  • CINIFILE : name of the initial Meso-NH file of model 1 (parent domain) which will be used to spawn model 2.

  • CINIFILEPGD : name of the PGD associated to the initial Meso-NH file 1 CINIFILE (father domain).

  • YDOMAIN : name of the file which defines the domain for model 2. If a domain file is provided for YDOMAIN, then all the information of namelist NAM_GRID2_SPA will be ignored.

  • YSPAFILE : optional name of the spawned Meso-NH file 2 (output file). If the user does not specify this name, or if YSPAFILE = CINIFILE, the code builds the spawned Meso-NH file name as:

    • YSPAFILE = CINIFILE.spaYSPANBR

    • YSPAFILE = CINIFILE.sprYSPANBR if YSONFILE is provided.

  • YSPANBR : NumBeR which will be added to CINIFILE to generate the Meso-NH file name of the SPAwned file (string of 2 characters)

  • YDADINIFILE : if GBAL_ONLY=.TRUE. : name of the CINIFILE dad.

  • YDADSPAFILE : if GBAL_ONLY=.TRUE. : name of the YSPAFILE dad.

Note

Program will check that YDADINIFILE and YDADSPAFILE have the same characteristics, before replacing the dad name of YSPAFILE by YDADSPAFILE instead of YDADINIFILE. YDADSPAFILE must exist before running the spawning job.

  • YSONFILE : optional name of a spawned Meso-NH file (input file). It must have the same resolution as the spawned Meso-NH file 2 (output file). The fields of YSONFILE will be used at points included in the domain defined by YDOMAIN or NAM_GRID2_SPA, instead of interpolated fields of CINIFILE. This allows to keep finest information when defining a new finest domain to follow atmospheric system.

NAM_SPAWN_SURF

NAM_SPAWN_SURF content

Fortran name

Fortran type

Default value

LSPAWN_SURF

LOGICAL

.TRUE.

  • LSPAWN_SURF : flag to perform or not the interpolation of all the surface fields (both physiographic and prognostic fields).

    • .TRUE. : the interpolations are made

    • .FALSE. : the interpolations are not made and therefore no surface field will be present in the output spawned file.