CSIRO Marine and Atmospheric Research is developing the smoke plume model within FIRE-DST and examining smoke dispersion, visibility concerns and estimating impacts on human health.
CSIRO is investigating smoke impacts on regional health from both severe events and the prescribed burning programs designed to offset their risks and the risk from reduced visibility from ground-level smoke. This will involve thedevelopment of spatial smoke and chemical emissions estimates for major and extensive fire events in southern Australia, and the application of these estimates to several atmospheric transport models to predict tracer concentrations and surface impacts.
Through comparison of the predictions against observations, CSIRO plans to assess the sensitivity of the predictions to parameter values in the emissions model. CSIRO believes that the most significant areas of uncertainty are associated with the plume rise and the dependence of emission factors on combustion properties; these issues are likely to occupy most of their attention.
CSIRO is coordinating the work with the Bushfire CRC fire behaviour project lead by Andrew Sullivan to undertake experimental burns in the CSIRO Pyrotron “fire wind tunnel”, to measure emission factors for methane, nitrous oxide, particulates and relevant air toxics covering a range of fuels and fire intensities. The activity is also coordinating the work with another Bushfire CRC project (Fire and Carbon) to extend the laboratory measurements to the field.
The objectives of this activity are:
- to develop a spatial emissions estimates for three major fire events in southern Australia,
- to apply this to several atmospheric transport models to predict tracer concentrations and surface impacts and,
- through comparison of the predictions against observations assess the sensitivity of the predictions to parameters values in the emissions model.
Key areas of uncertainty to be addressed are:
- plume rise and plume structure and
- the dependence of emission factors on combustion properties.
By focussing on major and extensive fire events in regions where air monitoring networks are active, for which fine scale mapping of fire extent is available, and a range of data are available for vegetation class, fuels, and combustion properties, it will be possible to assess the accuracy of emission estimates.
The issue of plume rise will be addressed by (1) and analysis of plume rise algorithms being developed for smoke dispersion models in Australia and internationally, and (2) assessment of the accuracy of these algorithms against observations of plume structure using satellite borne lidar (CALIPSO). Additionally, it is becoming apparent that current estimates of emission factors for forest fuels do not cover the full range of fire properties. The project will measure emission factors for methane, nitrous oxide, particulates and relevant air toxics during experimental burns covering a range of fuels and fire intensities in the CSIRO Pyrotron.