PDAF3_assim_offline_local_nondiagR

This page documents the routine PDAF3_assim_offline_local_nondiagR. The routine is part of the advanced PDAF3 interface that was introduced with PDAF V3.0.

The routine is used to execute the analysis step of the local ensemble filters LESTKF, LETKF and LSEIK for the case of a non-diagonal observation error covariance matrix. The routine is used for the offline coupled mode of PDAF, which is described on the page: Implementation Guide for Offline Coupling.

The interface for the routine contains names for routines that operate on the local analysis domains (marked by the suffix _l).

The interface when using one of the local filters (PDAF_localfilter()=1) is:

  SUBROUTINE PDAF3_assim_offline_local_nondiagR(U_init_dim_obs_pdafomi, U_obs_op_pdafomi, &
             U_init_n_domains, U_init_dim_l, U_init_dim_obs_l_pdafomi, U_prodRinvA_l_pdafomi, &
             U_prepoststep, status)

with the following arguments:

• U_init_dim_obs_pdafomi:
  The name of the user-supplied routine that initializes the observation information and provides the size of observation vector. This routine is part of an OMI observation module.
• U_obs_op_pdafomi:
  The name of the user-supplied routine that acts as the observation operator on some state vector. This routine is part of an OMI observation module.
• U_init_n_domains:
  The name of the user-supplied routine that provides the number of local analysis domains
• U_init_dim_l:
  The name of the user-supplied routine that provides the state dimension for a local analysis domain
• U_init_dim_obs_l_pdafomi:
  The name of the user-supplied routine that initializes the size of the observation vector for a local analysis domain. This routine is part of an OMI observation module.
• U_prodRinvA_l_pdafomi:
  The name of the user-supplied routine that computes the product of the inverse of the observation error covariance matrix with some matrix provided to the routine by PDAF. This routine is part of an OMI observation module.
• U_prepoststep:
  The name of the user-supplied pre/poststep routine as in PDAF_get_state
• status:
  The integer status flag. It is zero, if the routine is exited without errors.

Notes:

• The order of the routine names does not show the order in which these routines are executed. See the section on the order of the execution on the page on implementing the analysis step of the local filter algorithms.
• The difference to the routine PDAF3_assim_offline_local used for diagonal R-matrices is only in the additonal argument U_prodRinvA_l_pdafomi.
• The filter LNETF uses the separate routine PDAFlocalomi_assim_offline_lnetf_nondiagR.
• The filter LKNETF uses the separate routine PDAFlocalomi_assim_offline_lknetf_nondiagR
• It is recommended that the value of status_pdaf is checked in the program after the routine is executed. Only if its value is 0 the initialization was successful.

The user-supplied call-back routines are described on the page on implementing the analysis step of the local filters.