Harmonisation... 
Model intercomparison protocol |
Model intercomparison tool: Protocol and data archive
A topic which has been frequently discussed at the Harmonisation conferences is model evaluation, whereby models are compared against measurements.
As a complement to model evaluation, model intercomparison can be useful.
The present page concerns a tool for model intercomparison.
The tool has its value because it allows models to be intercompared in a systematic manner, and because it provides an insight
into model behaviour over a range of conditions.
A limitation of any tool like the present is that it cannot identify whether one model is better than another, because
it does not include concentration measurements.
The material was developed for the the UK Environment Agency by D.J. Hall et
al., and some of it was accessible from the Agency's Air Quality Modelling and
Assessment Unit (AQMAU) web site.
A summary of the work was presented at the 7th Harmonisation conference in
Belgirate through two papers:
- An intercomparison of the AERMOD, ADMS and ISC dispersion models for regulatory applications
D.J. Hall, A.M. Spanton, F. Dunkerley, M. Bennett and R.F. Griffiths. - An intercomparison of the AERMOD, ADMS and ISC dispersion models for regulatory applications: Dispersion over terrain.
F. Dunkerley, A.M. Spanton, D.J. Hall, M. Bennett and R.F. Griffiths.
The entire data archive is available from the present web site. Go on to the data archive pages...
Background info - excerpt from Introduction
In 1998 the UK Environment Agency commissioned a study to assess the AERMOD model for regulatory purposes in the UK and its performance in relation to the other advanced dispersion model in UK use, ADMS. Until the appearance of AERMOD, recent UK regulatory practice had been mainly based on ADMS and the use of a second major advanced model would raise regulatory problems if these two models performed differently. The study had three main objectives.
- Firstly to review past intercomparison studies of these advanced dispersion models in relation to the older Pasquill/Gifford types of model.
- Secondly, to develop a protocol for model assessment which could be used in this assessment and which would provide a consistent framework for future assessment of models for regulatory purposes.
- Thirdly, to compare the performance of AERMOD with ADMS and the older Pasquill/Gifford models and assess its performance for use in regulation.
This archive has been prepared in the interests of disseminating the test protocol as widely as possible and encouraging its further use, so that a historical perspective of dispersion model performance can be developed. It contains everything required to carry out further calculations with new models or revised versions of the ADMS or AERMOD models.