| | 1 | = PDAF_assimilate_ensrf = |
| | 2 | |
| | 3 | This page documents the routine `PDAF_assimilate_ensrf` of PDAF. The routine is used to execute the ENSRF/EAKF filters, which was added to PDAF with version 3.0. |
| | 4 | |
| | 5 | The routine is typically called in `assimilate_pdaf` or directly in the model code. However, for newer implementations we recommend to use the generic routine [wiki:PDAF3_assimilate_local] since less user-supplied call-back routines are required with the PDAF3 interface. |
| | 6 | |
| | 7 | The general aspects of the filter specific routines `PDAF_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 the fully-parallel implementation variant of the data assimilation system and can also be used for the flexible parallelization variant. |
| | 8 | |
| | 9 | The interface for the ENSRF/EAKF is the following: |
| | 10 | {{{ |
| | 11 | SUBROUTINE PDAF_assimilate_ensrf(U_collect_state, U_distribute_state, & |
| | 12 | U_init_dim_obs, U_obs_op, U_init_obs, U_init_obsvars, & |
| | 13 | U_localize_covar_serial, & |
| | 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 the inverse operation to `U_distribute_state` used in `PDAF_get_state` as well as 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. This is the inverse operation to `U_collect_state` |
| | 19 | * `U_init_dim_obs`: [[BR]]The name of the user-supplied routine that provides the size of observation vector |
| | 20 | * `U_obs_op`: [[BR]]The name of the user-supplied routine that acts as the observation operator on some state vector |
| | 21 | * `U_init_obs`: [[BR]]The name of the user-supplied routine that initializes the vector of observations |
| | 22 | * `U_init_obsvars`: [[BR]]The name of the user-supplied routine that initializes the vector of observation error variances. |
| | 23 | * `U_localize_covar_serial`: [[BR]]The name of the routine that applies the covariance localization for a single observation |
| | 24 | * `U_prepoststep`: [[BR]]The name of the pre/poststep routine as in `PDAF_get_state` |
| | 25 | * `U_next_observation`: [[BR]]The name of a user supplied routine that initializes the variables `nsteps`, `timenow`, and `doexit`. The same routine is also used in `PDAF_get_state`. |
| | 26 | * `status_pdaf`: [[BR]]The integer status flag. It is zero, if the routine is exited without errors. |
| | 27 | |
| | 28 | |
| | 29 | The user-supplied call-back routines are described on the page on [ImplementAnalysisENSRF implementing the analysis step of the ENSRF/EAKF]. |
| | 30 | |
| | 31 | It is recommended to check value of `status_pdaf` in the program after PDAF_assimilate_enkf is executed. Only if its value is 0 the initialization was successful. |
