The Australian Air Quality Forecasting System: Modelling of a Severe Smoke Event in Melbourne, Australia

Abstract

The Australian Air Quality Forecasting System (AAQFS) is a joint project between CSIRO Atmospheric Research, CSIRO Energy Technology, the Bureau of Meteorology, the EPA Victoria and the EPA of New South Wales to develop a high-resolution air quality forecasting system. Currently, numerical air quality forecasts are issued twice daily for two regions: the airshed of Melbourne and Geelong in Victoria, and the airshed of Sydney in New South Wales. The principal AAQFS role is to issue numerical forecasts to State EPAs in time for guidance and reference against current air quality forecasting procedures. On 11-12 January 2001, Melbourne experienced the worst visibility episode since the Ash Wednesday bushfire and the Melbourne Dust Storm in 1983. The episode was caused by thick smoke emitted from bushfires on King Island (some 300 km south of Melbourne) and Winchelsea (100 km south-west of Melbourne). Smoke from the Winchelsea fire arrived immediately behind a cold front in the afternoon of 11 January; smoke from the King Island fire first arrived in the Melbourne area during the evening and continued to cross the region throughout the following day. This paper describes a study in which the AAQFS was used to simulate the severe smoke event of 11-12 January 2001. The AAQFS demonstrated that the modeled distribution and transport of smoke plume were qualitatively in good agreement with the observation from the satellite and monitoring stations, with regard to the timing of plume arrival, dissipation and fumigation.