4.2.1.1. Namelist NAM_PGD_GRID

This namelist defines the grid type, either specified or from an existing surface file

Fortran name Fortran type default value
CGRID string of 10 characters "CONF PROJ "
YINIFILE string of 28 characters none
YINIFILETYPE string of 6 characters none
NOVMX integer 1

  • CGRID: type of grid and projection . It is used only if a file is not prescribed (see below). The different grid possibilities are:
    • "GAUSS " : this grid is a gaussian grid (global grid, that may be stretched, rotated, ...). Gaussian grids are not available in the open-source Surfex code.
    • "CONF PROJ " : this grid is a regular grid (in meters in x and y perpendicular directions) on conformal projection plan (Mercator, Lambert or polar stereographic).
    • "CARTESIAN " : this grid is a regular grid (in meters in x and y perpendicular directions), with no reference to real geographical coordinates.
    • "LONLAT REG" : this grid is defined as a regular latitude - longitude grid.
    • "LONLATVAL " : this grid is defined as a not regular latitude - longitude grid (all points and mesh sizes are defined).
    • "LONLAT ROT" : rotated lonlat (from Hirlam).
    • "IGN " : this grid type contains all IGN (French National Geographical Institute) possible Lambert projections
    • "NONE " : this grid is not regular. Only the number of points and the size of each grid mesh is prescribed. There is no positioning of each point compared to any other.
  • YINIFILE: name of the file used to define the grid. It is possible to define the grid as a subgrid of a previously created file. This is currently possible only for files that have a "CONF PROJ " or "CARTESIAN " grid type. The exact definition of the subgrid grid chosen is prescribed in a namelist (described below), depending on the type of grid available in the file chosen. The use of a file has priority on the CGRID type.
  • YINIFILETYPE: type of the YINIFILE file, if the latter is provided. YFILETYPE must be given. The following values are currently usable:
    • "MESONH" : the file type is a MESONH file.
    • "LFI"/"ASCII" : the file type is a PREP LFI or ASCII file.
  • NOVMX : number of points that can overlap each other in the user grid, for the calculation of physiographic fields.