MODULE DEFAULT_obs_def_mod¶

Overview¶

DEFAULT_obs_def.F90 is a template used by the program preprocess to create obs_def_mod.f90.
To read more detailed instructions on how to add new observation types, see the documentation for
MODULE obs_def_mod. obs_def_*_mod.f90 files are specified as input to the preprocess program by namelist,
and a new obs_def_mod.f90 file is generated which contains all the selected observation types.
Information from zero or more special obs_def modules, such as obs_def_1d_state_mod.f90 or
obs_def_reanalyis_bufr_mod.f90, (also documented in this directory) are incorporated into the
DEFAULT_obs_def_mod.F90 template by preprocess. If no special obs_def files are included in the preprocess
namelist, a minimal obs_def_mod.f90 is created which can only support identity forward observation operators. Any
identity observations on the obs_seq.out file will be assimilated, regardless of the obs types specified in
assimilate_these_obs_types.
The documentation below describes the special formatting that is included in the DEFAULT_obs_def_mod.F90 in order
to guide the preprocess program.

Up to seven sections of code are inserted into DEFAULT_obs_def_mod.F90 from each of the special obs_def_*_mod.f90 files. The insertion point for each section is denoted by a special comment line that must be included verbatim in DEFAULT_obs_def_mod.F90. These special comment lines and their significance are:

! DART PREPROCESS MODULE CODE INSERTED HERE Some special observation definition modules (see for instance obs_def_1d_state_mod.f90) contain code for evaluating forward observation operators, reading or writing special information about an observation definition to an obs sequence file, or for interactive definition of an observation. The entire module code section is inserted here, so the resulting output file will be completely self-contained. Fortran 90 allows multiple modules to be defined in a single source file, and subsequent module code can use previously defined modules, so this statement must preceed the rest of the other comment lines.
! DART PREPROCESS USE FOR OBS_QTY_MOD INSERTED HERE The quantities available to DART are defined by passing quantity files from DART/assimilation_code/modules/observations to preprocess. Unique integer values for each quantity are assigned by preprocess and the use statements for these entries are inserted here.
! DART PREPROCESS USE OF SPECIAL OBS_DEF MODULE INSERTED HERE Some special observation definition modules (see for instance obs_def_1d_state_mod.f90) contain code for evaluating forward observation operators, reading or writing special information about an observation definition to an obs sequence file, or for interactive definition of an observation. The use statements for these routines from the special observation definition modules are inserted here.
! DART PREPROCESS GET_EXPECTED_OBS_FROM_DEF INSERTED HERE Special observation definition modules must contain case statement code saying what to do to evaluate a forward observation operator for each observation type that they define. This code is inserted here.
! DART PREPROCESS READ_OBS_DEF INSERTED HERE Special observation definition modules must contain case statement code saying what to do to read any additional information required for each observation type that they define from an observation sequence file. This code is inserted here.
! DART PREPROCESS WRITE_OBS_DEF INSERTED HERE Special observation definition modules must contain case statement code saying what to do to write any additional information required for each observation type that they define to an observation sequence file. This code is inserted here.
! DART PREPROCESS INTERACTIVE_OBS_DEF INSERTED HERE Special observation definition modules must contain case statement code saying what to do to interactively create any additional information required for each observation type that they define. This code is inserted here.