PDAF_assimilate_prepost_si

This page documents the routine PDAF_assimilate_prepost_si of PDAF. It is basically an alias for the routine PDAF_prepost_si and we generally recommend to rather use PDAF_prepost_si to avoid the naming confusion that PDAF_assimilate_prepost_si holds 'assimilate' in its name, but is not performing assimilation.

The routine is typically called in assimilate_pdaf or directly in the model code.

The routine PDAF_assimilate_prepost_si is an alternative to the routines PDAF_assimilate_X_si where 'X' is the name of a filter method. The routine is used in the 'fully-parallel' implementation variant of PDAF. The purpose of PDAF_assimilate_prepost_si is to collect the ensemble information on the processes usually doing the filter analysis. However, in the case of PDAF_assimilate_prepost_si, no filter analysis step is performed when the ensemble integration is complete, but only the user-supplied pre/poststep routine is called to allow the user to analyze the forecast ensemble.

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 is the following:

  SUBROUTINE PDAF_assimilate_prepost_si(status_pdaf)

with the following arguments:

• status_pdaf: The integer status flag. It is zero, if PDAF_assimilate_prepostep_si is exited without errors.

The routine calls two user-supplied call-back routines. They are described, for example, on the page on implementing the analysis step of the ESTKF algorithm.

It is recommended that the value of status_pdaf is checked in the program after PDAF_assimilate_prepost_si is executed. Only if its value is 0 the execution was successful.