Changes between Initial Version and Version 1 of PDAF_assimilate_seek


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Timestamp:
Jan 15, 2015, 3:04:11 PM (6 years ago)
Author:
lnerger
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  • PDAF_assimilate_seek

    v1 v1  
     1= PDAF_assimilate_seek =
     2
     3This page documents the routine `PDAF_assimilate_seek` of PDAF.
     4
     5The routine is typically called in `assimilate_pdaf` or directly in the model code.
     6
     7The general aspects of the filter specific routines `PDAF_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 routines `PDAF_put_state_*' are used.
     8
     9The interface when using the SEEK filter is the following:
     10{{{
     11  SUBROUTINE PDAF_assimilate_seek(U_collect_state, U_distribute_state, U_init_dim_obs, &
     12                                 U_obs_op, U_init_obs, U_prepoststep, &
     13                                 U_prodRinvA, U_next_observation, status)
     14}}}
     15with the following arguments:
     16 * `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.
     17 * `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.
     18 * `U_init_dim_obs`: The name of the user-supplied routine that provides the size of observation vector
     19 * `U_obs_op`: The name of the user-supplied routine that acts as the observation operator on some state vector
     20 * `U_init_obs`: The name of the user-supplied routine that initializes the vector of observations
     21 * `U_prepoststep`: The name of the pre/poststep routine as in `PDAF_get_state`
     22 * `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.
     23 * `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`.
     24 * `status`: The integer status flag. It is zero, if `PDAF_assimilate_seek` is exited without errors.
     25
     26
     27The user-supplied call-back routines are described on the page on [ImplementAnalysisseek implementing the analysis step of the SEEK filter].
     28
     29It is recommended that the value of `status_pdaf` is checked in the program after PDAF_assimilate_seek is executed. Only if its value is 0 the initialization was successful.
     30
     31PDAF also has a [PdafSimplifiedInterface Simplified Interface] providing the routine `PDAF_assimilate_seek_si`. In the simplified interface, the name of the user-supplied routines have predefined names and do not appear in the call to `PDAF_assimilate_seek_si`.  More information on the pre-defined names is provided in the [ImplementAnalysisseek page on implementing the analysis step of the SEEK filter].
     32