Changes between Initial Version and Version 1 of PDAFlocalomi_assimilate


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Timestamp:
Sep 9, 2024, 3:49:40 PM (10 days ago)
Author:
lnerger
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  • PDAFlocalomi_assimilate

    v1 v1  
     1= PDAFlocalomi_assimilate =
     2
     3This page documents the routine `PDAFlocalomi_assimilate` of PDAF using the [wiki:PDAFlocal_overview PDAFlocal interface]. The routine is used to execute the analysis step of all local ensemble filters including the nonlinear filter LNETF (but except the [wiki:ImplementAnalysislenkfOmi LEnKF]) with PDAF-OMI.
     4
     5The routine is typically called in `assimilate_pdaf` or directly in the model code.
     6
     7The 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:PDAFomi_put_state_local PDAFomi_put_state_local] is used.
     8
     9The 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`).
     10Here, we list the full interface of the routine. Subsequently, the user-supplied routines specified in the call is explained.
     11
     12The interface when using one of the local filters is the following:
     13{{{
     14  SUBROUTINE PDAFlocalomi_assimilate(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_next_observation, status)
     18}}}
     19with the following arguments:
     20 * `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.
     21 * `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.
     22 * `U_init_dim_obs_pdafomi`: The name of the user-supplied routine that initializes the observation information and provides the size of observation vector
     23 * `U_obs_op_pdafomi`: The name of the user-supplied routine that acts as the observation operator on some state vector
     24 * `U_prepoststep`: The name of the pre/poststep routine as in `PDAF_get_state`
     25 * `U_init_n_domains`: The name of the routine that provides the number of local analysis domains
     26 * `U_init_dim_l`: The name of the routine that provides the state dimension for a local analysis domain
     27 * `U_init_dim_obs_l_pdafomi`: The name of the routine that initializes the size of the observation vector for a local analysis domain
     28 * `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`.
     29 * `status`: The integer status flag. It is zero, if the routine is exited without errors.
     30
     31Note:
     32 * 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.
     33
     34The user-supplied call-back routines are described on the page on [ImplementAnalysisLocal implementing the analysis step of the local filters].
     35
     36It 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.
     37
     38PDAF also has a [PdafSimplifiedInterface Simplified Interface] providing the routine `PDAFlocalomi_assimilate_si`. In the simplified interface, the name of the user-supplied routines have predefined names and do not appear in the call to `PDAFlocalomi_assimilate_si`.  More information on the pre-defined names is provided in the [ImplementAnalysisLocal page on implementing the analysis step of the local filters].
     39