Changes between Version 4 and Version 5 of ImplementAnalysisGlobal


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Timestamp:
Nov 16, 2020, 2:32:34 PM (9 days ago)
Author:
lnerger
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  • ImplementAnalysisGlobal

    v4 v5  
    2929With Version 1.16 of PDAF we introduced PDAF-OMI (observation module infrastructure). With OMI we provide generic routines for the analysis step, which only distinguish global and local filters. This page describes the implementation of the analysis step for global filters.
    3030
    31 For the analysis step of the global filters different operations related to the observations are needed. These operations are requested by PDAF by call-back routines supplied by the user and provided in the OMI structure. The names of the routines that are provided by the user are specified in the call to the routine `PDAF_assimilate_global` in the fully-parallel implementation (or `PDAF_put_state_global` for the 'flexible' implementation) that was discussed before. With regard to the parallelization, all these routines are executed by the filter processes (`filterpe=.true.`) only.
     31For the analysis step of the global filters different operations related to the observations are needed. These operations are requested by PDAF by call-back routines supplied by the user and provided in the OMI structure. The names of the routines that are provided by the user are specified in the call to the routine `PDAF_assimilate_global_omi` in the fully-parallel implementation (or `PDAF_put_state_global_omi` for the 'flexible' implementation) that was discussed before. With regard to the parallelization, all these routines are executed by the filter processes (`filterpe=.true.`) only.
    3232
    33 For completeness we discuss here all user-supplied routines that are specified in the interface to PDAF_assimilate_global. Thus, some of the user-supplied routines that are explained on the page describing the modification of the model code for the ensemble integration are repeated here.
     33For completeness we discuss here all user-supplied routines that are specified in the interface to PDAF_assimilate_global_omi. Thus, some of the user-supplied routines that are explained on the page describing the modification of the model code for the ensemble integration are repeated here.
    3434
    3535
    36 == `PDAF_assimilate_global` ==
     36== `PDAF_assimilate_global_omi` ==
    3737
    38 The general aspects of the filter specific routines `PDAF_assimilate_*` have been 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 is used, the routines `PDAF_put_state_*` is used as described further below. Here, we list the full interface of the routine. Subsequently, the full set of user-supplied routines specified in the call to `PDAF_assimilate_global` is explained.
     38The general aspects of the filter specific routines `PDAF_assimilate_*` have been 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 is used, the routines `PDAF_put_state_*` is used as described further below. Here, we list the full interface of the routine. Subsequently, the user-supplied routines specified in the call is explained.
    3939
    4040The interface when using one of the global filters is the following:
    4141{{{
    42   SUBROUTINE PDAF_assimilate_global(U_collect_state, U_distribute_state, U_init_dim_obs, &
    43                                  U_obs_op, U_init_obs, U_prepoststep, U_next_observation, status)
     42  SUBROUTINE PDAF_assimilate_global_omi(U_collect_state, U_distribute_state, &
     43                                 U_init_dim_obs, U_obs_op, U_init_obs, &
     44                                 U_prepoststep, U_next_observation, status)
    4445}}}
    4546with the following arguments:
     
    5051 * [#U_prepoststepprepoststep_ens_pdaf.F90 U_prepoststep]: The name of the pre/poststep routine as in `PDAF_get_state`
    5152 * [#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`.
    52  * `status`: The integer status flag. It is zero, if `PDAF_assimilate_estkf` is exited without errors.
     53 * `status`: The integer status flag. It is zero, if `PDAF_assimilate_global_omi` is exited without errors.
    5354
    5455
    55 == `PDAF_put_state_global` ==
     56== `PDAF_put_state_global_omi` ==
    5657
    57 When the 'flexible' implementation variant is chosen for the assimilation system, the routine `PDAF_put_state_global` has to be used instead of `PDAF_assimilate_global`. The general aspects of the filter specific routines `PDAF_put_state_*` have been described on the page [ModifyModelforEnsembleIntegration Modification of the model code for the ensemble integration]. The interface of the routine is identical with that of `PDAF_assimilate_global` with the exception the specification of the user-supplied routines `U_distribute_state` and `U_next_observation` are missing.
     58When the 'flexible' implementation variant is chosen for the assimilation system, the routine `PDAF_put_state_global_omi` has to be used instead of `PDAF_assimilate_global_omi`. The general aspects of the filter specific routines `PDAF_put_state_*` have been described on the page [ModifyModelforEnsembleIntegration Modification of the model code for the ensemble integration]. The interface of the routine is identical with that of `PDAF_assimilate_global` with the exception the specification of the user-supplied routines `U_distribute_state` and `U_next_observation` are missing.
    5859
    5960The interface when using one of the global filters is the following:
    6061{{{
    61   SUBROUTINE PDAF_put_state_global(U_collect_state, U_init_dim_obs, &
    62                                  U_obs_op, U_init_obs, U_prepoststep, status)
     62  SUBROUTINE PDAF_put_state_global_omi(U_collect_state, &
     63                                 U_init_dim_obs, U_obs_op, U_init_obs, &
     64                                 U_prepoststep, status)
    6365}}}
    6466
    6567== User-supplied routines ==
    6668
    67 Here all user-supplied routines are described that are required in the call to `PDAF_assimilate_global`. For some of the generic routines, we link to the page on [ModifyModelforEnsembleIntegration modifying the model code for the ensemble integration].
     69Here all user-supplied routines are described that are required in the call to `PDAF_assimilate_global_omi`. For some of the generic routines, we link to the page on [ModifyModelforEnsembleIntegration modifying the model code for the ensemble integration].
    6870
    6971To indicate user-supplied routines we use the prefix `U_`. In the template directory `templates/` as well as in the tutorial implementations in `tutorial/` these routines exist without the prefix, but with the extension `_pdaf.F90`. In the section titles below we provide the name of the template file in parentheses.
     
    9698The routine is called at the beginning of each analysis step.  For PDAF, it has to initialize the size `dim_obs_p` of the observation vector according to the current time step. Without parallelization `dim_obs_p` will be the size for the full model domain. When a domain-decomposed model is used, `dim_obs_p` will be the size of the observation vector for the sub-domain of the calling process.
    9799
    98 With PDAF_OMI, the routine just calls a routine from the observation module for each observation type.
     100With PDAF-OMI, the routine just calls a routine from the observation module for each observation type.
    99101
    100102
     
    116118For a model using domain decomposition, the operation is on the PE-local sub-domain of the model and has to provide the observed sub-state for the PE-local domain.
    117119
    118 With PDAF_OMI, the routine just calls a routine from the observation module for each observation type.
     120With PDAF-OMI, the routine just calls a routine from the observation module for each observation type.
    119121
    120122
     
    163165== Execution order of user-supplied routines ==
    164166
    165 The user-supplied routines are essentially executed in the order they are listed in the interface to `PDAF_assimilate_global`. The order can be important as some routines can perform preparatory work for later routines. For example, `U_init_dim_obs` prepares an index array that provides the information for executing the observation operator in `U_obs_op`. How this information is initialized is described in the documentation of OMI.
     167The user-supplied routines are essentially executed in the order they are listed in the interface to `PDAF_assimilate_global_omi`. The order can be important as some routines can perform preparatory work for later routines. For example, `U_init_dim_obs` prepares an index array that provides the information for executing the observation operator in `U_obs_op`. How this information is initialized is described in the documentation of OMI.
    166168
    167169Before the analysis step is called the following routine is executed:
     
    175177 1. [#U_prepoststepprepoststep_ens_pdaf.F90 U_prepoststep] (Call to act on the analysis ensemble, called with (positive) value of the time step)
    176178
    177 In case of the routine `PDAF_assimilate_global`, the following routines are executed after the analysis step:
     179In case of the routine `PDAF_assimilate_global_omi`, the following routines are executed after the analysis step:
    178180 1. [#U_distribute_statedistribute_state_pdaf.F90 U_distribute_state]
    179181 1. [#U_next_observationnext_observation_pdaf.F90 U_next_observation]