PDAF_prepost_si

This page documents the routine PDAF_prepost_si of PDAF.

PDAF_prepost_si is the variant of PDAF_prepost with the simplified interface. The difference between both routines is that in the simplified interface the names of the call-back subroutines are not specified. Instead the routine assumes that the call-back routines have a standard name as specified at the end of this page.

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

The routine PDAF_prepost_si is an alternative to the routines PDAF_assimilate_X_si where 'X' is the name of a filter method. The routine can be used with the 'fully parallel' implementation variant of PDAF. The purpose of PDAF_prepost_si is to collect the ensemble information on the processes usually doing the filter analysis. However, in the case of PDAF_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_put_state_* are described on the page Modification of the model code for the ensemble integration and its sub-page on inserting the analysis step. For the 'fully parallel' implementation variant the alternative routine PDAF_prepost is used.

The interface is the following:

  SUBROUTINE PDAF_prepost_si(status_pdaf)

with the following arguments:

• status_pdaf: The integer status flag. It is 0, if PDAF_put_state_prepost_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_prepost_si is executed. Only if its value is 0 the initialization was successful.