HOW SCENT MOVES: Understanding odour and environmental effects

Jason Cortis
Oct 13
2 min read

You may have heard the word odour "plume" or even in the past the odour "cone". This is all about how odours from a treat, all the way to a person might move in the environment.

Odour coming from a particular source will disperse in the air as a scent plume. That is not uniformly like you see with light or in some cases sound, but in a turbulent, meandering plume like pattern. Typically outdoors, plumes are carried downwind. When the wind flow is turbulent, which it almost always thanks to all the many variables that the scent molecules come into contact with (wind, temperature, buildings, terrain features etc.), the plume may break into pockets of higher and lower odour concentration, it may pool and it can swirl. This means the strongest odour is not always aligned with the source.

The Environment

The environment will always influence odours availability and behaviour. Wind can introduce chaotic eddies and chimney effects that fragment and deflect the odour, making scent harder to pinpoint or follow. Temperature and humidity can create more rise in air current or it can dilute and keep scent closer to the ground. The terrain and vegetation may push, trap, channel or block airflow and scent, so it's important you recognise these things to support your dog.

Canine Search Strategies and Adaptations

We know dogs use their amazing sense of smell and adjust behaviours it to suit; ground scenting (trailing directly along scent deposits on the ground) and air scenting (catching windborne scent in the air). For example, a trailing dog might follow a ground scent trail with its nose down when odour remains concentrated on the surface but in a wide open space, where odours are dispersed we might see the dog need to work wider with their noses up, sampling air currents and plumes of scent for that all important more concentrated target odour. Learning to understand how odour behaves in real-world environment can really set our dogs up for success; whether that means giving more line, starting them in the right area, or adjusting search areas to help, it can make all the difference and build you into an unstoppable team.

Join us for a search, track, or trailing session and experience first-hand how your dog reads and interprets scent and find out how we can take part on the other end of the lead.