Atmospheric particulate transport modelling in a controlled burn event

Smoke pollution from controlled burning of forested areas can be a major problem for populated areas, even those at some distance from the site of the burning. In particular, Perth, the largest city in Western Australia, is affected by smoke from controlled forest burns to the south of the city when meteorological conditions advect smoke over the city. Such controlled burns are extensively carried out on an annual basis in spring, early summer and late autumn by the Western Australian Department of Conservation and Land Management (CALM) in the southwest forests, in order to reduce flammable fuels and mitigate the undesirable social, economic, environmental and human problems caused by destructive wildfires. In this article, results are presented from a mesoscale model prediction of smoke trajectories from a controlled burn event that took place in November, 1995. In this example, two meteorological factors, a strong sea‐breeze front and a mesoscale low pressure system, unexpectedly turned the smoke back from its initial trajectory over the ocean to directly over Perth itself. The result was very high smoke concentration levels over the city and associated health concerns to residents as well as disruption to transport including the closing of Perth airport. The mesoscale guidance was very accurate and can provide valuable guidance when run routinely. Copyright © 1998 Royal Meteorological Society