Changes between Version 3 and Version 4 of ImplementAnalysisGlobal


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Timestamp:
Nov 16, 2020, 1:21:14 PM (9 days ago)
Author:
lnerger
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  • ImplementAnalysisGlobal

    v3 v4  
    1 = Implementation of the analysis step for the global filters =
     1= Implementation of the Analysis Step for the Global Filters =
    22
    33{{{
     
    1111<li><a href="ImplementationofAnalysisStep">Implementation of the analysis step</a></li>
    1212<ol>
    13 <li>Implementation for global filters</li>
    14 <li><a href="ImplementAnalysisLocal">Implementation for local filters</a></li>
    15 <li><a href="ImplementAnalysisestkf">Implementation for ESTKF</a></li>
    16 <li><a href="ImplementAnalysislestkf">Implementation for LESTKF</a></li>
    17 <li><a href="ImplementAnalysisetkf">Implementation for ETKF</a></li>
    18 <li><a href="ImplementAnalysisletkf">Implementation for LETKF</a></li>
    19 <li><a href="ImplementAnalysisseik">Implementation for SEIK</a></li>
    20 <li><a href="ImplementAnalysislseik">Implementation for LSEIK</a></li>
    21 <li><a href="ImplementAnalysisseek">Implementation for SEEK</a></li>
    22 <li><a href="ImplementAnalysisenkf">Implementation for EnKF</a></li>
     13<li>Implementation for Global Filters</li>
     14<li><a href="ImplementAnalysisLocal">Implementation for Local Filters</a></li>
    2315<li><a href="ImplementAnalysislenkf">Implementation for LEnKF</a></li>
    24 <li><a href="ImplementAnalysisnetf">Implementation for NETF</a></li>
    25 <li><a href="ImplementAnalysislnetf">Implementation for LNETF</a></li>
    2616<li><a href="ImplementAnalysispf">Implementation for PF</a></li>
    2717</ol>
     
    3727== Overview ==
    3828
    39 With Version 1.16 of PDAF we introduced PDAF-OMI (observation module infrastructure) and with it 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.
     29With 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.
    4030
    4131For 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.
     
    4636== `PDAF_assimilate_global` ==
    4737
    48 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 once more 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 full set of user-supplied routines specified in the call to `PDAF_assimilate_global` is explained.
    4939
    5040The interface when using one of the global filters is the following:
     
    5646 * [#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 `PDAF_get_state` as well as here.
    5747 * [#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.
    58  * [#U_init_dim_obsinit_dim_obs_pdaf.F90 U_init_dim_obs]: The name of the user-supplied routine that provides the size of observation vector
     48 * [#U_init_dim_obsinit_dim_obs_pdaf.F90 U_init_dim_obs]: The name of the user-supplied routine that initializes the observation information and provides the size of observation vector
    5949 * [#U_obs_opobs_op_pdaf.F90 U_obs_op]: The name of the user-supplied routine that acts as the observation operator on some state vector
    6050 * [#U_prepoststepprepoststep_ens_pdaf.F90 U_prepoststep]: The name of the pre/poststep routine as in `PDAF_get_state`
     
    7767Here 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].
    7868
    79 To indicate user-supplied routines we use the prefix `U_`. In the template directory `templates/` as well as in the example implementation in `testsuite/src/dummymodel_1D` 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.
     69To 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.
    8070
    8171In the subroutine interfaces some variables appear with the suffix `_p`. This suffix indicates that the variable is particular to a model sub-domain, if a domain decomposed model is used. Thus, the value(s) in the variable will be different for different model sub-domains.
     
    9484
    9585
    96 === `U_init_dim_obs` (init_dim_obs_pdaf.F90) ===
    97 
    98 This routine is used by all global filter algorithms (SEEK, SEIK, EnKF, ETKF, ESTKF).
     86=== `U_init_dim_obs` (callback_obs_pdafomi.F90) ===
    9987
    10088The interface for this routine is:
     
    10694}}}
    10795
    108 The routine is called at the beginning of each analysis step.  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.
     96The 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.
    10997
    110 Some hints:
    111  * It can be useful to not only determine the size of the observation vector at this point. One can also already gather information about the locations of the observations, which will be used later, e.g. to implement the observation operator. An array for the locations can be defined in a module like `mod_assimilation` of the example implementation.
     98With PDAF_OMI, the routine just calls a routine from the observation module for each observation type.
    11299
    113100
    114 === `U_obs_op` (obs_op_pdaf.F90) ===
    115 
    116 This routine is used by all global filter algorithms (SEEK, SEIK, EnKF, ETKF, ESTKF).
     101=== `U_obs_op` (callback_obs_pdafomi.F90) ===
    117102
    118103The interface for this routine is:
     
    131116For 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.
    132117
    133 Hint:
    134  * If the observation operator involves a global operation, e.g. some global integration, while using domain-decomposition one has to gather the information from the other model domains using MPI communication.
     118With PDAF_OMI, the routine just calls a routine from the observation module for each observation type.
    135119
    136120
     
    187171 1. [#U_prepoststepprepoststep_ens_pdaf.F90 U_prepoststep] (Call to act on the forecast ensemble, called with negative value of the time step)
    188172 1. [#U_init_dim_obsinit_dim_obs_pdaf.F90 U_init_dim_obs]
    189  1. [#U_obs_opobs_op_pdaf.F90 U_obs_op] (multiple calls for each ensemble members)
     173 1. [#U_obs_opobs_op_pdaf.F90 U_obs_op] (multiple calls, one for each ensemble member)
    190174 1. [#U_prodRinvAprodrinva_pdaf.F90 U_prodRinvA]
    191175 1. [#U_prepoststepprepoststep_ens_pdaf.F90 U_prepoststep] (Call to act on the analysis ensemble, called with (positive) value of the time step)