PDAF - the Parallel Data Assimilation Framework

PDAF is developed, hosted and maintained at the Computing Center of the Alfred Wegener Institute.

News August 1, 2019 GMD discussion paper: Efficient ensemble data assimilation for coupled models with the Parallel Data Assimilation Framework: Example of AWI-CM. Discussion is open until September 26. July 4, 2019 Release of Version 1.14 (release notes) (Adding functionality to generate synthetic observations; adding a particle filter; adding data assimilation for the Lorenz-63 model example; 3 bug fixes) April 25, 2019 New paper: Particle filters for high-dimensional geoscience applications: a review by PJ van Leeuwen, HR Künsch, L Nerger, R Potthast, S Reich, Q. J. Royal. Meteorol. Soc., 145, 2335-2365 doi:10.1002/qj.3551

The Parallel Data Assimilation Framework - PDAF - is a software environment for ensemble data assimilation. PDAF simplifies the implementation of the data assimilation system with existing numerical models. With this, users can obtain a data assimilation system with less work and can focus on applying data assimilation.

PDAF provides fully implemented and optimized data assimilation algorithms, in particular ensemble-based Kalman filters like LETKF and LSEIK. It allows users to easily test different assimilation algorithms and observations. PDAF is optimized for the application with large-scale models that usually run on big parallel computers and is applicable for operational applications. However, it is also well suited for smaller models and even toy models.

PDAF provides a standardized interface that separates the numerical model from the assimilation routines. This allows to perform the further development of the assimilation methods and the model independently. New algorithmic developments can be readily made available through the interface such that they can be immediately applied with existing implementations. The test suite of PDAF provides small models for easy testing of algorithmic developments and for teaching data assimilation.

PDAF is a community open-source project. Its functionality will be further extended by input from research projects. In addition, users are welcome to contribute to the further enhancement of PDAF, e.g. by contributing additional assimilation methods or interface routines for different numerical models.

Content:

• Features and requirements of PDAF
• Implementation Concept of PDAF
• Software download
• Basic Documentation
  • First Steps with PDAF
  • Assimilation with the Lorenz-96 model and PDAF
  • Assimilation with the Lorenz-63 model and PDAF
  • Description of the software package
  • Implementation tutorials
  • Which filter should one use?
  • Generating ensembles
• Full Documentation
  • Implementation Guide for the online assimilation system
  • Implementation Guide for the offline assimilation program
  • Diagnostic routines
  • Generate synthetic observations for twin experiments
  • Overview of filter-specific options
  • Adding a filter algorithm to PDAF
  • Lists for direct access to documentation on particular routines

• Publications and Presentations involving and about PDAF