= PDAF_assimilate_letkf_si = This page documents the routine `PDAF_assimilate_letkf_si` 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 [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. The interface when using the LETKF is the following: {{{ SUBROUTINE PDAF_assimilate_letkf_si(status_pdaf) }}} with the following arguments: * `status_pdaf`: The integer status flag. It is zero, if `PDAF_assimilate_letkf` is exited without errors. The routine calls several user-supplied call-back routines. They are described on the page on [ImplementAnalysisletkf implementing the analysis step of the LETKF algorithm]. 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 execution of the routine was successful.