The influence of the averaging period on calculation of air pollution using a puff model

The main goal of this paper is to assess differences in calculations of air pollution using standard,one hour wind averages and shorter time averages of ten minutes. A puff model has been used to estimateconcentrations of a passive substance for four days in January, March, June and September as representativesof variations of wind and stability during a year. Meteorological inputs were ten meters winds and two meterstemperature, measured at a weather station. The additional data of temperature gradients, measured at the samestation two times a day, were also available.The standard practice is to form hourly averages of wind speed and hourly prevailing direction based on thedata tape records. To infer the importance of the shorter averaging period, tapes were re-analyzed forming tenminutes averages. After extrapolation to fifty meters heights we forced a puff model with these, two differentlyaveraged, wind data.