The dispersion program AUSTAL (starting with version 3) is the reference implementation to Annex 2 of the TA Luft 2021. The program is the successor of AUSTAL2000 (ending with version 2), the reference implementation to Annex 3 of the TA Luft 2002.
The TA Luft (Technical Instruction on Air Quality Control) has been amended in view of available advanced techniques and European Directives. The new TA Luft has been published on July 30, 2002 (Gemeinsames Ministerialblatt) and thus comes into force October 1, 2002.
Annex 3 of the new TA Luft specifies a Lagrangian particle model according to guideline VDI 3945 Part 3 (example implementation: IBJparticle) to be applied for dispersion calculations. In course of updating Annex 3, the computer program AUSTAL2000 has been developed as an example implementation of Annex 3, together with a documentation of its setup and application in the context of the new TA Luft (UFOPLAN project 200 43 256, "development of a model-based assessment system for regulatory environmental protection", Janicke Consulting on behalf of the German Environment Agency, UBA).
The program package AUSTAL2000 is a tool for applying the algorithms of Annex 3 of the new TA Luft in practice. The UBA has provided it to the public already in its draft version. This is to be seen as a service that aims for quality assurance and harmonization in connection with the dispersion calculation from the very beginning. The statements of Annex 3 themself are already sufficient for a program implementation of the described algorithms. AUSTAL2000 provides a reference implementation against which other programs, that claim to implement the algorithms of Annex 3, can be checked.
September 30, 2002, German Environment Agency
The history of AUSTAL2000 started almost exactly 21 years ago. At the NATO CCMS conference in San Francisco, which took place end of August 1981, I had just presented my formulation of Lagrangian modelling in inhomogeneous turbulence, parallel to similar works by Wilson and Legg & Raupach; in doing so, I delivered a promise made to Hanna during a conference in the preceding year in Amsterdam. The preparations for the TA Luft 1983 had not yet finished, nevertheless the participants already discussed how the TA Luft should develop on an intermediate and long-term time scale.
After the conference, we therefore sat together in the small village Kirkwood, in the mountains east from Jackson, in order to bring our ideas together (in the framework of the UBA project "handbook for immission calculations"). We, that was: Werner Klug, Paul Lühring, Rainer Stern, Robert Yamartino, and myself. Key points for a long-term concept that should reach about 5 to 7 years into the future were, among others:
* Abandonment of meteorological statistics in favour of the simulation of
individual situations in form of a time series.
* Abandonment of classifications in favour of continuous meteorological parameters
(e.g. the Monin-Obukhov length).
* Replacement of the Gaussian model by a Lagrangian model.
* Provision for topographical effects.
* Modelling of NO/NO2 conversion.
* Improved modelling of the dispersion and deposition of dust.
Now, after 21 years, major points of that former concept have been realised with the new TA Luft that comes into force tomorrow, October 1, 2002. Maybe one should meet again in the mountains and discuss how the dispersion model of the TA Luft should develop over the next 20 years.
September 30, 2002, Lutz Janicke