Abstract
This paper investigates an odour incident that occurred in April 2008 with an initially unknown source and cause which resulted in hundreds of notifications of odour complaints across England. Detailed analysis of the incident illustrates how a combination of the geographical distribution of odour reports together with Met Office data and back-trajectory modelling can be utilised to trace the source location and source term of the odour. The analysis suggests that the source of the odorant was not locally generated and that long range transport from Northern Europe was the likely explanation. This requires potentially exceptional source strength so that dilution at distance is sufficient to lead to odour perception thousands of km away. The proposed cause is suggested to be wide-spread spreading of agricultural slurry. This is common practice in Europe during the spring, and has implications for future reports of odour travelling extensive distances and resulting in long-range pollution events.