PDAF3_put_state_3dvar

This page documents the routine PDAF3_put_state_3dvar of PDAF. The routine is part of the advanced PDAF3 interface that was introduced with PDAF V3.0.

The routine is typically called in assimilate_pdaf or directly in the model code.

The general aspects of the filter specific routines PDAF3_put_state_* are described on the page Modification of the model code for the ensemble integration and its sub-page on inserting the analysis step.

The routine is used for the offline mode of PDAF. It can also be used in the 'flexible' parallelization implementation variant of the data assimilation system, but starting with PDAF-3 we recommend to use PDAF3_assimilate_3dvar, which is also used with the 'fully-parallel' implementation variant.

The interface for using the parameterized 3D-Var is:

  SUBROUTINE PDAF3_put_state_3dvar(U_collect_state, &
                                 U_init_dim_obs_pdafomi, U_obs_op_pdafomi, &
                                 U_cvt, U_cvt_adj, U_obs_op_lin_pdafomi, obs_op_adj_pdafomi, &
                                 U_prepoststep, outflag)

with the following arguments:

• U_collect_state:
  The name of the user-supplied routine that initializes a state vector from the array holding the ensemble of model states from the model fields. This is basically the inverse operation to U_distribute_state used in PDAF_get_state and also here.
• 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_cvt: The name of the user-supplied routine that applies the control-vector transformation (square-root of the B-matrix) on some control vector to obtain a state vector.
• U_cvt_adj: The name of the user-supplied routine that applies the adjoint control-vector transformation (with square-root of the B-matrix) on some state vector to obtain the control vector.
• 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_obs_op_lin_pdafomi: The name of the user-supplied routine that acts as the linearized observation operator on some state vector. This routine is part of an OMI observation module.
• `U_obs_op_adj_pdafomi]: The name of the user-supplied routine that acts as the adjoint observation operator on some state vector. 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. * status:
  The integer status flag. It is zero, if the routine is exited without errors. 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 [ImplementAnalysis_3DVar implementing the analysis step of 3D-Var with OMI].