Changes between Initial Version and Version 1 of PDAF3_assimilate_en3dvar


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Timestamp:
Mar 30, 2025, 11:27:08 AM (4 days ago)
Author:
lnerger
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  • PDAF3_assimilate_en3dvar

    v1 v1  
     1= PDAF3_assimilate_en3dvar =
     2
     3This page documents the routine `PDAF3_assimilate_en3dvar`. The routine is part of the advanced PDAF3 interface that was introduced with PDAF V3.0. 
     4
     5This routine is use to run the ensemble 3D-Var with either LESTKF or the global ESTKF for updating the ensemble perturbations.
     6
     7The routine is typically called in `assimilate_pdaf` or directly in the model code.
     8
     9The 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 is used in both the fully-parallel and the flexible parallelization variant of the data assimilation system.
     10
     11
     12The interface is:
     13{{{
     14SUBROUTINE PDAF3_assimilate_en3dvar(U_collect_state, U_distribute_state, &
     15                                 U_init_dim_obs_pdafomi, U_obs_op_pdafomi, &
     16                                 U_cvt_ens, U_cvt_adj_ens, U_obs_op_lin_pdafomi, & 
     17                                 U_obs_op_adj_pdafomi, &
     18                                 U_init_n_domains_p, U_init_dim_l, U_init_dim_obs_l_pdafomi, &
     19                                 U_prepoststep, U_next_observation, outflag)
     20}}}
     21with the following arguments:
     22 * `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.
     23 * `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.
     24 * `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.
     25 * `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.
     26 * `U_cvt_ens`: [[BR]]The name of the user-supplied routine that applies the ensemble control-vector transformation (square-root of the B-matrix) on some control vector to obtain a state vector.
     27 * `U_cvt_adj_ens`: [[BR]]The name of the user-supplied routine that applies the adjoint ensemble control-vector transformation (with square-root of the B-matrix) on some state vector to obtain the control vector.
     28 * `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.
     29 * `U_obs_op_lin_pdafomi`: [[BR]]The name of the user-supplied routine that acts as the linearized observation operator on some state vector.  This routine is part of an OMI observation module.
     30 * `U_obs_op_adj_pdafomi: [[BR]]The name of the user-supplied routine that acts as the adjoint observation operator on some state vector. This routine is part of an OMI observation module.
     31 * `U_init_n_domains`: [[BR]]The name of the user-supplied routine that provides the number of local analysis domains
     32 * `U_init_dim_l`: [[BR]]The name of the user-supplied routine that provides the state dimension for a local analysis domain
     33 * `U_init_dim_obs_l_pdafomi`: [[BR]]The name of the user-supplied routine that initializes the size of the observation vector for a local analysis domain
     34 * `U_prepoststep`: [[BR]]The name of the user-supplied pre/poststep routine as in `PDAF_get_state`
     35 * `U_next_observation`: [[BR]]The name of the user-supplied routine that initializes the variables `nsteps`, `timenow`, and `doexit`. The same routine is also used in `PDAF_get_state`.
     36 * `status`: [[BR]]The integer status flag. It is zero, if the routine is exited without errors. 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.
     37
     38The user-supplied call-back routines are described on the page on [wiki:ImplementAnalysis_3DEnVar implementing the analysis step of 3D Ensemble Var with OMI].