wiki:ImplementationofAnalysisStep_PDAF23

Version 24 (modified by lnerger, 7 days ago) ( diff )

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Implementation of the analysis step with OMI (PDAF2)

Implementation Guide: Analysis Step in PDAF2

  1. Main page: Implementing the analysis step with OMI
    1. Ensemble filters
      1. General overview for ensemble filters
      2. Implementation for Global Filters
      3. Implementation for Local Filters
      4. Implementation for LEnKF
    2. 3D-Var methods
      1. General overview for 3D-Var methods
      2. Implementation for 3D-Var
      3. Implementation for 3D Ensemble Var
      4. Implementation for Hybrid 3D-Var
This page can be reached from different
parts of the documentation:

Back to Offline Mode: Implementation Guide

Back to Online Mode: Implementation Guide

Back to PDAF-OMI Guide

PDAF-OMI Guide for PDAF2

  1. Overview
  2. callback_obs_pdafomi.F90
  3. Observation Modules
  4. Observation operators
  5. Checking error status
  6. Debugging functionality
  7. Implementing the analysis step with OMI
  8. Porting an existing implementation to OMI
  9. Additional OMI Functionality
  10. Using domain-limited observations
  11. Using nondiagonal R-matrices
This page describes the implementation approach of PDAF2. This is intended for reference for existing implementations performed for PDAF2. See the page on implementing the analysis step with PDAF3 for the updated recommendations.

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.

With PDAF-OMI many of the routines are general and hence usable for all filter algorithms. There are some differences between the local and global filters and the LEnKF. The general routines will be repeated, but they are marked as general.

While different routines are used for the online and offline modes of PDAF, the implementation of the analysis is generally generic. As such we combine this here for both the online and offline modes.

There are three different routines that call the filter analysis step.

  • General overview of routines required to implement the analysis step for ensemble filters.
  1. Implementation of the analysis for Global Filters
  2. Implementation of the analysis for Local Filters
  3. Implementation of the analysis for the LEnKF using covariance localization

For the application of the 3D-Var methods there are separate routines (added with PDAF 2.0):

  • General overview of routines required to implement the analysis step for 3D-Var.
  1. Implementation of the analysis for 3D-Var with parameterized background covariance matrix
  2. Implementation of the analysis for 3D Ensemble Var
  3. Implementation of the analysis for hybrid 3D-Var

Implementation of the analysis step without OMI

PDAF-OMI was introduced with version 1.16 of PDAF. While we recommend using OMI, the implementation of the analysis step without OMI using PDAF's full interface is still possible.

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'.

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