Talking About the Weather

As we enter storm season it seems to be a good time to give consideration to one of the most important  aspects of assessing air quality, understanding and utilising proper meteorological data. It is hard to underestimate the degree to which the weather affects local and regional air quality, when considering the source-pathway-receptor method of environmental assessment it comprises the entirety of the ‘pathway’ aspect.

Of most concern to us as air quality practitioners is the wind. Both wind speed and direction can have a significant impact on how well pollutants from a range of sources are dispersed and are carried to nearby sensitive receptors. Strong prevailing wind conditions can lead to downwind receptors experiencing significant effects at a much longer range while upwind receptors are relatively unaffected even at close proximity to the source. It’s for this reason that the local physical conditions such as street canyons, hills and valleys must be considered as even a small change in wind conditions can lead to big changes pollutant dispersion.

Whilst wind is the most important factor there are several others that require consideration when talking about air pollution. Precipitation (i.e., rain) can lead to pollutants being ‘washed out’ of the atmosphere, atmospheric pressure can lead to inversion zones and changes in the boundary layer that trap pollutants and even the temperature can effect the rate at which pollutants decompose, or are formed in atmospheric reactions.  

Thanks to our industry leading suppliers, here at Vale we are well equipped and experienced to handle air quality assessments at a wide range of sites and weather conditions.