Coupling/IO fields (transient variables)

Each coupling/IO field possibly received or provided by the component model from/to its external environment (another model or a disk file) through prism_get or prism_put call has to be described in the component PMIOD by one element `transient' with the following attributes and sub-elements:

• attribute 'local_name': the field name (which must match 2$^{nd}$ argument in the corresponding PSMILe call prism_def_var , see section 5.4.1);

• attribute `long_name': gives a general description of the variable;

• element `transient_standard_name': the standard variable names following the CF convention (if it exist). This uniquely identifies the nature of the coupling/IO field.

  In case of bundles, one element giving a generic name (e.g. temperature) plus one element per bundle species giving a specific name for the species (e.g sea_water_temperature, air_temperature, snow_temperature) need to be specified.

• element `physics': a description of the coupling/IO field physical constraints:
  • attribute `transient_type': the coupling/IO field physical type (either `single' or `bundle')

  • element `physical_units': the coupling/IO field units

  • element `valid_min': its physically acceptable minimum value

  • element `valid_max': its physically acceptable maximum value

  • element `nbr_bundles': for bundle variables, the number of bundles.

• element `numeric', whose attribute `datatype' provides the coupling/IO field numeric type: either
  xs:real, xs:double, or xs:integer

• element `intent', which describes if the coupling/IO field may be exported or imported, or both. The sub-elements of `intent' are:
  • element `output': if the coupling field can be exported through PSMILe prism_put call (see section 5.6.1), this element shall contain:
    • element `minimal_period', which is the period at which the prism_put is called in the code (to define this period the developer may specify a number of seconds, minutes, hours, days, months, and/or years, with respectively the sub-elements `nbr_secs', `nbr_mins', `nbr_hours', `nbr_days', `nbr_months', `nbr_years').
    • element `source_transformation': the transformation that needs to be performed on the output coupling/IO field in the source component PSMILe ; if needed, this element contains only the element `source_local_transformation' which in turn contains only the element `scattering': the `scattering' should be specified as true by the developer in the PMIOD and should not be changed by the user in the SMIOC. It is performed on an output coupling/IO field below the prism_put by the source PSMILe . It is required when grid information transfered to the PSMILe includes the masked points and when the array transfered to the prism_put API is a vector gathering only the non-masked points. Note that this complex structure is used here to specify scattering to be coherent with the `source_transformation' structure of the SMIOC file (see 6.5)

  • element `input': if the coupling/IO field can be imported through a prism_get call (see section 5.6.2 ), this element shall contain:
    • element `minimal_period', which is the period at which the prism_get is called in the code (to define this period the developer may specify a number of seconds, minutes, hours, days, months, and/or years, with respectively the sub-elements `nbr_secs', `nbr_mins', `nbr_hours', `nbr_days', `nbr_months', `nbr_years').
    • element `target_transformation': the transformation that needs to be performed on the input coupling/IO field in the target component PSMILe ; if needed, this element contains only the element `target_local_transformation' which in turn contains only the element `gathering': the `gathering' should be specified as true by the developer in the PMIOD and should not be changed by the user in the SMIOC. It is performed on an input coupling/IO field below the prism_get by the target PSMILe . It is required when the grid information transfered to the PSMILe covers the whole grid (masked points included), and when the array transfered through prism_get API is a vector gathering only the non-masked points. Note that this complex structure is used here to specify gathering to be coherent with the `target_transformation' structure of the SMIOC file (see 6.5)