Changes between Initial Version and Version 1 of PDAF_assimilate_lestkf


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Timestamp:
Jan 15, 2015, 4:54:32 PM (6 years ago)
Author:
lnerger
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  • PDAF_assimilate_lestkf

    v1 v1  
     1= PDAF_assimilate_lestkf =
     2
     3This page documents the routine `PDAF_assimilate_lestkf` 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 LESTKF algorithm is the following:
     10{{{
     11  SUBROUTINE PDAF_assimilate_lestkf(U_collect_state, U_distribute_state, U_init_dim_obs_f, U_obs_op_f, &
     12                                  U_init_obs_f, U_init_obs_l, U_prepoststep, U_prodRinvA_l, &
     13                                  U_init_n_domains, U_init_dim_l, U_init_dim_obs_l, &
     14                                  U_g2l_state, U_l2g_state, U_g2l_obs, &
     15                                  U_init_obsvar, U_init_obsvar_l, U_next_observation, status_pdaf)
     16}}}
     17with the following arguments:
     18 * `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 [ModifyModelforEnsembleIntegration#PDAF_get_state PDAF_get_state]
     19 * `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.
     20 * `U_init_dim_obs_f`: The name of the user-supplied routine that provides the size of the full observation vector
     21 * `U_obs_op_f`: The name of the user-supplied routine that acts as the full observation operator on some state vector
     22 * `U_init_obs_f`: The name of the user-supplied routine that initializes the full vector of observations
     23 * `U_init_obs_l`: The name of the user-supplied routine that initializes the vector of observations for a local analysis domain
     24 * `U_prepoststep`: The name of the pre/poststep routine as in `PDAF_get_state`
     25 * `U_prodRinvA_l`: 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.
     26 * `U_init_n_domains`: The name of the routine that provides the number of local analysis domains
     27 * `U_init_dim_l`: The name of the routine that provides the state dimension for a local analysis domain
     28 * `U_init_dim_obs_l`: The name of the routine that initializes the size of the observation vector for a local analysis domain
     29 * `U_g2l_state`: The name of the routine that initializes a local state vector from the global state vector
     30 * `U_l2g_state`: The name of the routine that initializes the corresponding part of the global state vector from the the provided local state vector
     31 * `U_g2l_obs`: The name of the routine that initializes a local observation vector from a full observation vector
     32 * `U_init_obsvar`: The name of the user-supplied routine that provides a global mean observation error variance (This routine will only be executed, if an adaptive forgetting factor is used)
     33 * `U_init_obsvar_l`: The name of the user-supplied routine that provides a mean observation error variance for the local analysis domain (This routine will only be executed, if a local adaptive forgetting factor is used)
     34 * `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`.
     35 * `status_pdaf`: The integer status flag. It is zero, if `PDAF_assimilate_lestkf` is exited without errors.
     36
     37
     38
     39Note:
     40 * The order of the routine names does not show the order in which these routines are executed. See the [ImplementAnalysislestkf#Executionorderofuser-suppliedroutines section on the order of the execution] on the page on implementing the analysis step of the LESTKF algorithm.
     41
     42The user-supplied call-back routines are described on the page on [ImplementAnalysislestkf implementing the analysis step of the LESTKF].
     43
     44It is recommended that the value of `status_pdaf` is checked in the program after PDAF_assimilate_lestkf is executed. Only if its value is 0 the initialization was successful.
     45
     46PDAF also has a [PdafSimplifiedInterface Simplified Interface] providing the routine `PDAF_assimilate_lestkf_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_lestkf_si`.  More information on the pre-defined names is provided in the [ImplementAnalysislestkf page on implementing the analysis step of the LESTKF algorithm].