Implementation of the analysis step

This page describes the implementation of the analysis step without using PDAF-OMI. Please see the page on the analysis with OMI for the more modern and efficient implementation variant using PDAF-OMI.

The implementation of the analysis step requires that the user-supplied routines whose names are given in the call to the filter-specific put-state routine are implemented with full functionality.

Several of the routines are general and hence usable for all filter algorithms. There are some differences between the available local and global filters. The routines are described in separate pages for each filter algorithm. The general routines will be repeated, but they are marked as general.

Filter-specific implementations for global filters:

Filter-specific implementations for domain-local filters:

Filter-specific implementation for filters with covariance localization:

Method-specific implementation for 3D-Var schemes:

(The filters ESTKF and LESTKF have been added with PDAF version 1.8; the filters LEnKF, NETF and LNETF have been addid with PDAF version 1.12; the 3D-Var methods have been added with PDAF version 2.0.)

Testing the full implementation

After the implementation of the user-supplied routines for the analysis step, the data assimilation system is fully implemented. In order to test the program one has to compile it without setting 'PDAF_NO_UPDATE'.

To speed up the testing it can be useful to comment out the time stepping part. In that case only the model initialization and the assimilation cycle would be executed, without the usually costly time integration of the ensemble. One should then check if all user-supplied routines perform as they should.

Last modified 2 years ago Last modified on Dec 9, 2021, 1:18:36 PM