| 1 | = PDAFomi_assimilate_local = |
| 2 | |
| 3 | This page documents the routine `PDAF_assimilate_local` of PDAF. The routine is used to execute the analysis step of all local ensemble Kalman filters (except the LEnKF) with PDAF-OMI. |
| 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 `PDAFomi_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. When the 'flexible' implementation variant, the routine [wiki:PDAomi_put_state_local PDAomi_put_state_local] is used. |
| 8 | |
| 9 | The interface for the routine `PDAFomi_assimilate_local` contains names for routines that operate on the local analysis domains (marked by the suffix `_l`). Further there are routines that convert between a local and a global model state vector (`U_g2l_state` and `U_l2g_state`). |
| 10 | Here, we list the full interface of the routine. Subsequently, the user-supplied routines specified in the call is explained. |
| 11 | |
| 12 | The interface when using one of the local filters is the following: |
| 13 | {{{ |
| 14 | SUBROUTINE PDAFomi_assimilate_local(U_collect_state, U_distribute_state, & |
| 15 | U_init_dim_obs_pdafomi, U_obs_op_pdafomi, & |
| 16 | U_prepoststep, U_init_n_domains, U_init_dim_l, & |
| 17 | U_init_dim_obs_l_pdafomi, U_g2l_state, U_l2g_state, & |
| 18 | U_next_observation, status) |
| 19 | }}} |
| 20 | with the following arguments: |
| 21 | * [#U_collect_statecollect_state_pdaf.F90 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 [ModifyModelforEnsembleIntegration#PDAF_get_state PDAF_get_state] and also here. |
| 22 | * [#U_distribute_statedistribute_state_pdaf.F90 U_distribute_state]: The name of a user supplied routine that initializes the model fields from the array holding the ensemble of model state vectors. |
| 23 | * [#U_init_dim_obs_pdafomicallback_obs_pdafomi.F90 U_init_dim_obs_pdafomi]: The name of the user-supplied routine that initializes the observation information and provides the size of observation vector |
| 24 | * [#U_obs_op_pdafomicallback_obs_pdafomi.F90 U_obs_op_pdafomi]: The name of the user-supplied routine that acts as the observation operator on some state vector |
| 25 | * [#U_prepoststepprepoststep_ens_pdaf.F90 U_prepoststep]: The name of the pre/poststep routine as in `PDAF_get_state` |
| 26 | * [#U_init_n_domainsinit_n_domains_pdaf.F90 U_init_n_domains]: The name of the routine that provides the number of local analysis domains |
| 27 | * [#U_init_dim_linit_dim_l_pdaf.F90 U_init_dim_l]: The name of the routine that provides the state dimension for a local analysis domain |
| 28 | * [#U_init_dim_obs_l_pdafomicallback_obs_pdafomi.F90 U_init_dim_obs_l_pdafomi]: The name of the routine that initializes the size of the observation vector for a local analysis domain |
| 29 | * [#U_g2l_stateg2l_state_pdaf.F90 U_g2l_state]: The name of the routine that initializes a local state vector from the global state vector |
| 30 | * [#U_l2g_statel2g_state_pdaf.F90 U_l2g_state]: The name of the routine that initializes the corresponding part of the global state vector from the provided local state vector |
| 31 | * [#U_next_observationnext_observation.F90 U_next_observation]: 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`. |
| 32 | * `status`: The integer status flag. It is zero, if `PDAFomi_assimilate_local` is exited without errors. |
| 33 | |
| 34 | Note: |
| 35 | * The order of the routine names does not show the order in which these routines are executed. See the [#Executionorderofuser-suppliedroutines section on the order of the execution] at the bottom of this page. |
| 36 | |
| 37 | The user-supplied call-back routines are described on the page on [ImplementAnalysisLocal implementing the analysis step of the local filters]. |
| 38 | |
| 39 | It is recommended that the value of `status_pdaf` is checked in the program after PDAFomi_assimilate_local is executed. Only if its value is 0 the initialization was successful. |
| 40 | |
| 41 | PDAF also has a [PdafSimplifiedInterface Simplified Interface] providing the routine `PDAFomi_assimilate_local_si`. In the simplified interface, the name of the user-supplied routines have predefined names and do not appear in the call to `PDAFomi_assimilate_local_si`. More information on the pre-defined names is provided in the [ImplementAnalysisLocal page on implementing the analysis step of the local filters]. |
| 42 | |