Dispersion modelling considerations for transient emissions from elevated point sources

research
dispersion modelling
air quality modelling
An examination of modelling considerations required to accurately represent the transient and episodic nature of emissions from elevated point sources in dispersion calculations.
Authors

D.C. Carslaw

S.D. Beevers

Published

January 1, 2002

Dispersion modelling considerations for transient emissions from elevated point sources

D.C. Carslaw, S.D. Beevers

Atmospheric Environment, 2002

Dispersion modelling of elevated point sources that emit infrequently presents particular challenges, since predictions of peak concentrations become increasingly susceptible to the prevailing meteorology as the fraction of time a source emits decreases. A probabilistic approach is adopted in which concentrations at receptor locations are randomly sampled across multiple years to explore how source operating time affects high-percentile concentration predictions of SO2 from a single stack and from a network of four stacks. Results show that for locations rarely downwind of sources and for low operational times, the inter-annual variability of predicted concentrations is high, with implications for the way annual statistics are interpreted in impact assessments.