Changes between Version 10 and Version 11 of ImplementAnalysisseek


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Timestamp:
May 5, 2014, 1:58:37 PM (10 years ago)
Author:
lnerger
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  • ImplementAnalysisseek

    v10 v11  
    1111<li><a href="ImplementationofAnalysisStep">Implementation of the analysis step</a></li>
    1212<ol>
     13<li><a href="ImplementAnalysisestkf">Implementation for ESTKF</a></li>
     14<li><a href="ImplementAnalysislestkf">Implementation for LESTKF</a></li>
     15<li><a href="ImplementAnalysisetkf">Implementation for ETKF</a></li>
     16<li><a href="ImplementAnalysisletkf">Implementation for LETKF</a></li>
    1317<li><a href="ImplementAnalysisseik">Implementation for SEIK</a></li>
    1418<li><a href="ImplementAnalysislseik">Implementation for LSEIK</a></li>
    15 <li><a href="ImplementAnalysisetkf">Implementation for ETKF</a></li>
    16 <li><a href="ImplementAnalysisletkf">Implementation for LETKF</a></li>
    1719<li>Implementation for SEEK</li>
    1820<li><a href="ImplementAnalysisenkf">Implementation for EnKF</a></li>
    19 <li><a href="ImplementAnalysisestkf">Implementation for ESTKF</a></li>
    20 <li><a href="ImplementAnalysislestkf">Implementation for LESTKF</a></li>
    2121</ol>
    2222<li><a href="AddingMemoryandTimingInformation">Memory and timing information</a></li>
    … …  
    2929== Overview ==
    3030
    31 For the analysis step of the SEEK filter different operations related to the observations are needed. These operations are requested by PDAF by calling user-supplied routines. Intentionally, the operations are split into separate routines in order to keep the operations rather elementary. This procedure should simplify the implementation. The names of the required routines are specified in the call to the routine `PDAF_put_state_seek`. With regard to the parallelization, all these routines are executed by the filter processes (`filterpe=.true.`) only.
    32 
    33 For completeness we discuss here all user-supplied routines that are specified in the interface to PDAF_put_state_seek. Thus, some of the user-supplied routines that are explained on the page explaining the modification of the model code for the ensemble integration for the SEIK filter are repeated here, but specified for the SEEK filter.
     31For the analysis step of the SEEK filter different operations related to the observations are needed. These operations are requested by PDAF by calling user-supplied routines. Intentionally, the operations are split into separate routines in order to keep the operations rather elementary. This procedure should simplify the implementation. The names of the required routines are specified in the call to the routine `PDAF_assimilate_seek` for the fully-parallel configuration (or `PDAF_put_state_seek` for the flexible configuration). With regard to the parallelization, all these routines are executed by the filter processes (`filterpe=.true.`) only.
     32
     33For completeness we discuss here all user-supplied routines that are specified in the interface to PDAF_assimialte_seek. Thus, some of the user-supplied routines that are explained on the page explaining the modification of the model code for the ensemble integration for the SEIK filter are repeated here, but specified for the SEEK filter.
    3434
    3535The SEEK filter is very similar to the SEIK filter. In fact, the SEIK filter has been introduced as an interpolated (Pham et al., 1998) version of the SEEK filter. Due to the similarity of both filters, the interface to the user-supplied routines is almost identical. Several of the user-suppplied routines can be identical for SEEK and SEIK. Differences are marked in the text below. The implementation of the SEEK filter follows its original description by Pham et al. (1998) as reviewed by Nerger et al. (Tellus, 2005).
    3636
    37 There is no localized variant of the SEEK filter in PDAF. In Nerger et al. (Tellus, 2005), the SEIK filter performed much better than the SEEK filter. Due to this, we focused more on the SEIK filter after this comparison study. For real applications, we recommend using SEIK or ETKF, or their local variants LSEIK or LETKF.
     37There is no localized variant of the SEEK filter in PDAF. In Nerger et al. (Tellus, 2005), the SEIK filter performed much better than the SEEK filter. Due to this, we focused more on the SEIK filter after this comparison study. For real applications, we recommend using the ESTKF or its local variants LESTKF (In our study Nerger et al. (Mon. Wea. Rev., 2012, [http://dx.doi.org/doi:10.1175/MWR-D-11-00102.1 doi:10.1175/MWR-D-11-00102.1]), we developed the ESTKF method as an alternative to both the SEIK filter and the ETKF, to give better compute performance and assimilation results).
    3838 
    3939
    40 == `PDAF_put_state_seek` ==
    41 
    42 The general espects of the filter specific routines `PDAF_put_state_*` have been described on the page [ModifyModelforEnsembleIntegration Modification of the model code for the ensemble integration]. Here, we list once more the full interface specifically for the SEEK filter. Subsequently, the full set of user-supplied routines specified in the call to `PDAF_put_state_seek` is explained.
     40== `PDAF_assimilate_seek` ==
     41
     42The 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_seek` is explained.
     43is explained.
    4344
    4445The interface when using the SEEK filter is the following:
    4546{{{
    46   SUBROUTINE PDAF_put_state_seek(U_collect_state, U_init_dim_obs, U_obs_op, &
    47                                  U_init_obs, U_prepoststep, U_prodRinvA, status)
     47  SUBROUTINE PDAF_assimilate_seek(U_collect_state, U_distribute_state, U_init_dim_obs, &
     48                                 U_obs_op, U_init_obs, U_prepoststep, &
     49                                 U_prodRinvA, U_next_observation, status)
    4850}}}
    4951with the following arguments:
    50  * [#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`
     52 * [#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` and also here.
     53 * [#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.
    5154 * [#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
    5255 * [#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
    … …  
    5457 * [#U_prepoststepprepoststep_seek_pdaf.F90 U_prepoststep]: The name of the pre/poststep routine as in `PDAF_get_state`
    5558 * [#U_prodRinvAprodrinva_pdaf.F90 U_prodRinvA]: The name of the user-supplied routine that computes the product of the inverse of the observation error covariance matrix with some matrix provided to the routine by PDAF. This operation occurs during the analysis step of the SEEK filter.
    56  * `status`: The integer status flag. It is zero, if `PDAF_put_state_seek` is exited without errors.
    57 
     59 * [#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`.
     60 * `status`: The integer status flag. It is zero, if `PDAF_assimilate_seek` is exited without errors.
     61
     62== `PDAF_put_state_seek` ==
     63
     64When the 'flexible' implementation variant is chosen for the assimilation system, the routine `PDAF_put_state_seek` has to be used instead of `PDAF_assimilate_seek`. 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_seek` with the exception the specification of the user-supplied routines `U_distribute_state` and `U_next_observation` are missing.
     65
     66The interface when using the SEEK filter is the following:
     67{{{
     68  SUBROUTINE PDAF_put_state_seek(U_collect_state, U_init_dim_obs, U_obs_op, &
     69                                 U_init_obs, U_prepoststep, U_prodRinvA, status)
     70}}}
    5871
    5972== User-supplied routines ==
    6073
    61 Here, all user-supplied routines are described that are required in the call to `PDAF_put_state_seek`. For some of the generic routines, we link to the page on [ModifyModelforEnsembleIntegration modifying the model code for the ensemble integration].
     74Here, all user-supplied routines are described that are required in the call to `PDAF_assimilate_seek`. For some of the generic routines, we link to the page on [ModifyModelforEnsembleIntegration modifying the model code for the ensemble integration].
    6275
    6376To 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.
    … …  
    6982
    7083This routine is independent of the filter algorithm used.
    71 See the page [ModifyModelforEnsembleIntegration#U_collect_statecollect_state_pdaf.F90 modifying the model code for the ensemble integration] for the description of this routine.
     84See the page on [InsertAnalysisStep#U_collect_statecollect_state_pdaf.F90 inserting the analysis step] for the description of this routine.
     85
     86
     87=== `U_distribute_state` (distribute_state_pdaf.F90) ===
     88
     89This routine is independent of the filter algorithm used.
     90See the page on [InsertAnalysisStep#U_distribute_statedistribute_state_pdaf.F90 inserting the analysis step] for the description of this routine.
    7291
    7392
    … …  
    189208
    190209
     210=== `U_next_observation` (next_observation_pdaf.F90) ===
     211
     212This routine is independent of the filter algorithm used.
     213See the page on [InsertAnalysisStep#U_next_observationnext_observation_pdaf.F90 inserting the analysis step] for the description of this routine.
     214
     215
    191216== Execution order of user-supplied routines ==
    192217
    193 For the SEEK filter, the user-supplied routines are essentially executed in the order they are listed in the interface to `PDAF_put_state_seek`. The order can be important as some routines can perform preparatory work for later routines. For example, `U_init_dim_obs` can prepare an index array that provides the information for executing the observation operator in `U_obs_op`.
     218For the SEEK filter, the user-supplied routines are essentially executed in the order they are listed in the interface to `PDAF_assimilate_seek`. The order can be important as some routines can perform preparatory work for later routines. For example, `U_init_dim_obs` can prepare an index array that provides the information for executing the observation operator in `U_obs_op`.
    194219
    195220Before the analysis step is called the following routine is executed:
    … …  
    204229 1. [#U_prodRinvAprodrinva_pdaf.F90 U_prodRinvA]
    205230 1. [#U_prepoststepprepoststep_seek_pdaf.F90 U_prepoststep] (Call to act on the analysis ensemble, called with (positive) value of the time step)
     231
     232In case of the routine `PDAF_assimilate_seek`, the following routines are executed after the analysis step:
     233 1. [#U_distribute_statedistribute_state_pdaf.F90 U_distribute_state]
     234 1. [#U_next_observationnext_observation_pdaf.F90 U_next_observation]