| 1 | = PDAF3_assimilate_en3dvar_estkf = |
| 2 | |
| 3 | This page documents the routine `PDAF3_assimilate_en3dvar_estkf` of PDAF. |
| 4 | |
| 5 | The routine is typically called in `assimilate_pdaf` or directly in the model code. |
| 6 | |
| 7 | The general aspects of the filter specific routines `PDAF3_assimilate_*` are described on the page [ModifyModelforEnsembleIntegration Modification of the model code for the ensemble integration] and its sub-page on [InsertAnalysisStep inserting the analysis step]. The routine is used in both the fully-parallel and the flexible parallelization variant of the data assimilation system. |
| 8 | |
| 9 | The interface is: |
| 10 | {{{ |
| 11 | SUBROUTINE PDAF3_assimilate_en3dvar_estkf(U_collect_state, U_distribute_state, & |
| 12 | U_init_dim_obs_pdafomi, U_obs_op_pdafomi, & |
| 13 | U_cvt_ens, U_cvt_adj_ens, U_obs_op_lin_pdafomi, U_obs_op_adj_pdafomi, & |
| 14 | U_prepoststep, U_next_observation, outflag) |
| 15 | }}} |
| 16 | with the following arguments: |
| 17 | * `U_collect_state`: [[BR]]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 [ModifyModelforEnsembleIntegration#PDAF_get_state PDAF_get_state] and also here. |
| 18 | * `U_distribute_state`: [[BR]]The name of a user supplied routine that initializes the model fields from the array holding the ensemble of model state vectors. |
| 19 | * `U_init_dim_obs_pdafomi`: [[BR]]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. |
| 20 | * `U_obs_op_pdafomi`: [[BR]]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. |
| 21 | * `U_cvt_ens`: [[BR]]The name of the user-supplied routine that applies the ensemble control-vector transformation (square-root of the B-matrix) on some control vector to obtain a state vector. |
| 22 | * `U_cvt_adj_ens`: [[BR]]The name of the user-supplied routine that applies the adjoint ensemble control-vector transformation (with square-root of the B-matrix) on some state vector to obtain the control vector. |
| 23 | * `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. |
| 24 | * `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. |
| 25 | * `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. |
| 26 | * `U_prepoststep`: [[BR]]The name of the user-supplied pre/poststep routine as in `PDAF_get_state` |
| 27 | * `U_next_observation`: [[BR]]The name of the user-supplied routine that initializes the variables `nsteps`, `timenow`, and `doexit`. The same routine is also used in `PDAF_get_state`. |
| 28 | * `status`: [[BR]]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. |
| 29 | |
| 30 | The user-supplied call-back routines are described on the page on [wiki:ImplementAnalysis_3DEnVar implementing the analysis step of 3D Ensemble Var with OMI]. |
| 31 | |
| 32 | |
| 33 | |