Changes between Initial Version and Version 1 of PDAF3_assimilate_local

Timestamp:

Mar 23, 2025, 3:05:14 PM (10 days ago)

Author:

lnerger

Comment:

--

PDAF3_assimilate_local

@@ +1 @@
+= PDAF3_assimilate_local =
+
+This page documents the routine `PDAF3_assimilate_local`. The routine is part of the advanced [wiki:PDAF3_interface PDAF3 interface] that was introduced with PDAF V3.0.  
+
+The routine is used to execute the analysis step of all local ensemble filters including the nonlinear filter LNETF and the ENSRF/EAKF (but except the [wiki:ImplementAnalysislenkfOmi LEnKF]). The routine uses the functionalities provided by PDAF-OMI and PDAFlocal to yield a minimum number of arguments.
+
+The routine is typically called in `assimilate_pdaf` or directly in the model code.
+
+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 can be used in both the fully-parallel and the flexible parallelization variant of the data assimilation system. 
+
+The interface for the routine `PDAF3_assimilate_local` 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 is the following:
+{{{
+  SUBROUTINE PDAF3_assimilate_local(U_collect_state, U_distribute_state, &
+             U_init_dim_obs_pdafomi, U_obs_op_pdafomi, &
+             U_init_n_domains, U_init_dim_l, U_init_dim_obs_l_pdafomi, &
+             U_prepoststep, U_next_observation, status)
+}}}
+with the following arguments:
+ * `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.
+ * `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.
+ * `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.
+ * `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.
+ * `U_prepoststep`: [[BR]]The name of the pre/poststep routine as in `PDAF_get_state`
+ * `U_init_n_domains`: [[BR]]The name of the routine that provides the number of local analysis domains
+ * `U_init_dim_l`: [[BR]]The name of the routine that provides the state dimension for a local analysis domain
+ * `U_init_dim_obs_l_pdafomi`: [[BR]]The name of the routine that initializes the size of the observation vector for a local analysis domain. This routine is part of an OMI observation module.
+ * `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`.
+ * `status`: [[BR]]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 [ImplementAnalysisLocal#Executionorderofuser-suppliedroutines section on the order of the execution] on the page on implementing the analysis step of the local filter algorithms. 
+ * The routine is identical to the routine `PDAFlocalomi_assimilate` of PDAF 2.3. However, the argument `U_prepostep` is at a different place here.
+
+The user-supplied call-back routines are described on the page on [ImplementAnalysisLocal implementing the analysis step of the local filters].
+
+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.