Meteorological conditions govern the transport and dispersion of pollutants from emission sources to receptors. When modelling emission sources, it is important to use meteorological data that represent the site. Sufficient meteorological data should be available to ensure that worst case conditions are adequately represented in the model predictions. This requirement is especially important when the predicted concentrations must be reported on a statistical basis (e.g. 98th percentile).
A careful analysis of local meteorological conditions is important for other reasons as, for example:
- Identifying an operation as the source of odour by correlating meteorological data with the time of the complaint.
- Describe the prevailing dispersion meteorology at the site including: wind rose diagrams, or joint frequency distribution of wind speed and wind direction, or 1 year of site-representative records of hourly average wind speed and wind direction.
- Conduct odour-generating activities or use odour-generating equipment during the least sensitive time of day or under the most favourable weather conditions. For example, wait until the wind is blowing away from sensitive receptors before flushing a sewage system.