Version 1 (modified by 2 months ago) (diff) | ,
---|
PDAF_assimilate_lnetf
This page documents the routine PDAF_assimilate_lnetf
of PDAF.
The routine is typically called in assimilate_pdaf
or directly in the model code.
The general aspects of the filter specific routines PDAF_assimilate_*
are described on the page Modification of the model code for the ensemble integration and its sub-page on 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.
The interface when using the LNETF algorithm is the following:
SUBROUTINE PDAF_assimilate_lnetf(U_collect_state, U_distribute_state, U_init_dim_obs_f, U_obs_op_f, & U_init_obs_f, U_init_obs_l, U_prepoststep, U_likelihood_l, & U_init_n_domains, U_init_dim_l, U_init_dim_obs_l, & U_g2l_state, U_l2g_state, U_g2l_obs, & U_init_obsvar, U_init_obsvar_l, U_next_observation, status_pdaf)
with the following arguments:
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 toU_distribute_state
used in PDAF_get_stateU_distribute_state
: The name of a user supplied routine that initializes the model fields from the array holding the ensemble of model state vectors.U_init_dim_obs_f
: The name of the user-supplied routine that provides the size of the full observation vectorU_obs_op_f
: The name of the user-supplied routine that acts as the full observation operator on some state vectorU_init_obs_f
: The name of the user-supplied routine that initializes the full vector of observationsU_init_obs_l
: The name of the user-supplied routine that initializes the vector of observations for a local analysis domainU_prepoststep
: The name of the pre/poststep routine as inPDAF_get_state
U_likelihood_l
: The name of the user-supplied routine that computes the local likelihood of an ensemble state.U_init_n_domains
: The name of the routine that provides the number of local analysis domainsU_init_dim_l
: The name of the routine that provides the state dimension for a local analysis domainU_init_dim_obs_l
: The name of the routine that initializes the size of the observation vector for a local analysis domainU_g2l_state
: The name of the routine that initializes a local state vector from the global state vectorU_l2g_state
: The name of the routine that initializes the corresponding part of the global state vector from the the provided local state vectorU_g2l_obs
: The name of the routine that initializes a local observation vector from a full observation vectorU_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)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)U_next_observation
: The name of a user supplied routine that initializes the variablesnsteps
,timenow
, anddoexit
. The same routine is also used inPDAF_get_state
.status_pdaf
: The integer status flag. It is zero, ifPDAF_assimilate_letkf
is exited without errors.
Note:
- The order of the routine names does not show the order in which these routines are executed. See the section on the order of the execution on the page on implementing the analysis step of the LETKF algorithm.
The user-supplied call-back routines are described on the page on implementing the analysis step of the LETKF.
It is recommended that the value of status_pdaf
is checked in the program after PDAF_assimilate_letkf is executed. Only if its value is 0 the initialization was successful.
PDAF also has a Simplified Interface providing the routine PDAF_assimilate_letkf_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_letkf_si
. More information on the pre-defined names is provided in the page on implementing the analysis step of the LETKF algorithm.