Title: Turbulent fluctuations and their use in estimating compliance with standards and in model evaluation

Authors: S.J. Dyster, D.J. Thomson, C.A. McHugh, D.J. Carruthers

Addresses: Cambridge Environmental Research Consultants Ltd., 3 King's Parade, Cambridge, CB2 1SJ, UK. UK Meteorological Office, London Road, Bracknell, Berkshire RG12, 2SZ, UK. Cambridge Environmental Research Consultants Ltd., 3 King's Parade, Cambridge, CB2 1SJ, UK. Cambridge Environmental Research Consultants Ltd., 3 King's Parade, Cambridge, CB2 1SJ, UK

Abstract: Turbulent fluctuations are important in dispersion problems where short timescale peak values can be critical. These situations include: a) releases of toxic, flammable or odourous substances where high short time scale impacts may be dangerous or cause a nuisance; b) estimating concentrations for regulatory purposes for comparison with limits based on a short timescale, such as the UK 15-minute or WHO 10-minute levels for SO₂; c) assessing the uncertainties in dispersion model predictions and aiding model comparison with measured data. The ADMS 3 dispersion model includes a module to calculate turbulent fluctuations which is based on a ||two particle dispersion|| concept but has much in common with Gifford|s meandering plume model. It has been used in critical applications where odour and exceedences of a regulatory value were the issues. In this paper, the fluctuations model is described and each of the three applications is illustrated.

Keywords: ADMS; clipped-normal distribution; correlations; exceedences; fluctuations; turbulence.

DOI: 10.1504/IJEP.2001.000606

International Journal of Environment and Pollution, 2001 Vol.16 No.1/2/3/4/5/6, pp.57-68

Published online: 07 Jul 2003 *

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