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| Scientists' Contributions | ||
Peter Builtjes, TNO-MEP, Apeldoorn, and University Utrecht, the Netherlands, e-mail: p.j.h.builtjes@mep.tno.nl
In the middle of last year I was approached by the scientific committee of the 24 the NATO/CCMS International Technical Meeting (ITM) on Air Pollution Modelling and its Application with the question whether I would be willing to give an invited talk with the above given title, at their conference, held now in May this year in Boulder, USA. I felt honoured, and agreed without much reflection or hesitation.
However, when the deadline of submission of the text was approaching, I became increasingly nervous. Several thoughts went through my mind. How would I find the time to go through all the relevant and old literature, they should have asked a retired person! What is actually a milestone, and how strict is the definition of air pollution modelling, and are areas as atmospheric chemistry, emissions, meteorology to be included or not? What would happen in case I forgot an item what was a major milestone for others, would I make enemies, or the other way round, friends??
I discussed my struggles at several moments with my colleagues at different meetings which I attended. Gradually the paper got more shape in my mind. Milestones should be clearly distinguishable breakthroughs. The focus should be on air pollution modelling in a strict sense, with only mentioning other areas in passing. And if I would forget things, too bad, I should do what I could during the restricted evenings and weekends available. Just before the deadline the paper was ready, and only needed to be scribbled down and send in.
For the full paper see the reference below, here I only want to present some of the items I addressed to give you a flavour. Air pollution modelling originates from the first studies on turbulence and dispersion in the atmosphere by Taylor, 1915, followed by a number of studies like Batchelor, 1950. Dispersion from low and high level point sources was first studied by Barry Smith in 1957. A major field experiment took place in 1957/8, the famous Prairy Grass experiment. The detailed analysis of the results led to the formulation of the Gaussian Plume Model. A very comprehensive overview was given in the book by Pasquill, Atmospheric Diffusion, of which the first edition appeared in 1962. Amazingly, the new versions of this book are still in print.
Other related activities were started, the Journal of atmospheric environment had its first issue in 1967, the first NATO/CCMS ITM was held in 1971.
Shortly after 1970 the awareness grew that air pollution was not only a local phenomenon. Next to the Gaussian Plume Model more long range model were developed and applied. Lagrangian models as developed by Rohde, 1972, and Eliassen, 1975 were mainly used in Europe, for SO2. Eulerian grid models as developed by Reynolds and Roth, 1973 were mainly used in the US, for episodic ozone.
The picture that originates is that an impressive amount of work had been done already before 1980, and that in fact the basic knowledge and modelling tools were established by 1980. This does not mean that after 1980 no progress has been made. The Gaussian plume model has been improved using the new developments to describe the convective boundary layer. The long range models, especially the Eulerian grid models have been improved using better numerics, enlarging the gasphase chemistry to include aerosols, better description for dry deposition, etc see for example Peters 1995. Also much more attention is given nowadays to model validation.
However, it is difficult, or I found it difficult to determine milestones after 1980 which are as outstanding as the milestones I could find before 1980.
I have been struggling with the explanation for this phenomenon. Maybe I was to stupid to see the milestones, or I did not put enough time in it to look for them. Maybe I am to close to all this work, and it takes distance to see milestones. Maybe milestones are not to be expected in this period of post-modernism, or more simple, air pollution modelling has grown mature, so no milestones can be expected anymore.
I gave my invited talk in Boulder, coming up there with still one possible recent milestone: data-assimilation, and mentioning that of course everybody has his or her own milestone, your first double refereed paper. I enjoyed doing this paper, although I also realised that a proper history and milestone detection would require much more time. I am not sure whether I made more enemies or friends as a result of my talk. However, I was asked to join the scientific committee of the NATO/CCMS, so it could have not been that bad...
Builtjes, P.J.H., Major twentieth century milestones in air pollution modelling and its application. Proceedings Millennium NATO/CCMS ITM on air pollution modelling and its application, Boulder ,USA, May 2000
Remark: In that paper also the references mentioned above can be found
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