PDAF_local_type

This page documents the function PDAF_local_type of PDAF, which are introduced with PDAF 3.0.

The function is an alternative to the routine PDAF_get_local_type. Here the value is the return value of the function, while for PDAF_get_local_type the return value is an argument of the routine.

The function returns the information on the localization type of the selectd filter. With this one can distinguish filter using domain localization (LESTKF, LETKF, LSEIK, LNETF), covariance localization (LEnKF), or covariance localization with observation handling like domain localization (ENSRF/EAKF).

The function can be called in init_dim_obs_OBSTYPE, of each observation module to control whether PDAFomi_set_localize_covar is called to initialize covariance localization.

The interface is the following:

  INTEGER FUNCTION PDAF_local_type()

without arguments. The return value is

• (0) no localization; global filter
• (1) domain localization (LESTKF, LETKF, LNETF, LSEIK)
• (2) covariance localization (LEnKF)
• (3) covariance localization. but observation handling like domain localization (ENSRF/EAKF)

The return value can be directly used, e.g. as

  IF (PDAF_local_type() > 0) THEN
    CALL PDAFomi_set_localize_covar(...)

Notes:

• The function can also be used as an alternative to PDAF_localfilter in assimilate_pdaf.