Colin Simpson | University of NSW at Canberra (original) (raw)
I recently completed a PhD in Environmental Science at the Centre for Atmospheric Research, University of Canterbury, New Zealand. The PhD was funded by the Bushfire Cooperative Research Centre and focused on numerical modelling of atmospheric interactions with wildland fire. I am now working as a Postdoctoral Research Fellow at the University of New South Wales in Canberra, Australia.
Address: University of New South Wales at Canberra
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Research Articles by Colin Simpson
Refereed Conference Papers by Colin Simpson
The Mt Cook Station fire was ignited in 100% cured grass by a chainsaw on 16 January 2008. The fi... more The Mt Cook Station fire was ignited in 100% cured grass by a chainsaw on 16 January 2008. The fire was eventually controlled on 22 January, although mop-up of hot spots continued for several weeks. The fire burned 756 hectares, predominantly in dense stands of wilding conifers and light scrub, making it the largest wildland fire in the South Canterbury Rural Fire District for over a decade. Periods of high intensity fire behaviour were observed during the main fire runs in the dense wilding stands in the 24 hr period following ignition.
Blow-up fire behaviour can be broadly defined as a rapid escalation in the intensity or forward r... more Blow-up fire behaviour can be broadly defined as a rapid escalation in the intensity or forward rate of spread of a wildland fire, and is often accompanied by extreme pyro-convection associated with rapid smoke release and dispersion. Blow-up fire behaviour is difficult to predict and has been linked to firefighter fatalities, making it an important fire management hazard. compiled the first observational dataset of categorised wind speed and direction profiles associated with blow-up fire behaviour. Low-level jets, varying in height between 30 and 1000 m above ground level (AGL), are a common feature in Byram's wind-profile types. Additional studies have qualitatively discussed how low-level jets can influence wildland fire behaviour and pyro-convective plume dynamics. However, there has been little quantitative testing and analysis of the physical processes linking low-level jets and blow-up fire behaviour.
Recent work has demonstrated that under conditions of extreme fire weather, bushfires burning in ... more Recent work has demonstrated that under conditions of extreme fire weather, bushfires burning in rugged terrain can exhibit highly atypical patterns of propagation, which can have a dramatic effect on subsequent fire development. In particular, wildfires have been observed to spread laterally across steep, lee-facing slopes in a process that has been termed 'fire channelling'. Fire channelling, in turn, has been associated with serious escalation in fire activity and the development of pyrocumulonimbus storms. Coupled fire-atmosphere modelling using large eddy simulation has indicated that the fire channelling phenomenon occurs in response to fire-induced vorticity on the fire's flanks in the immediate lee of a ridge line. In this paper we extend previous modelling, using the WRF-Fire coupled fire-atmosphere model, to specifically consider the effect of wind speed in generating the fire-induced vorticity necessary to drive the lateral spread associated with fire channelling.
Conference Posters by Colin Simpson
Papers by Colin Simpson
This study presents new knowledge of the environmental sensitivity of a dynamic mode of atypical ... more This study presents new knowledge of the environmental sensitivity of a dynamic mode of atypical wildland fire spread on steep lee-facing slopes. This is achieved through a series of idealized numerical simulations performed with the Weather Research and Forecasting (WRF) and WRF-Fire coupled atmosphere-fire models. The sensitivity of the atypical lateral fire spread across lee slopes is tested for a varying background wind speed, wind direction relative to the terrain aspect, and lee slope steepness. The results indicate that the lateral spread characteristics are highly sensitive to each of these environmental conditions, and there is a broad agreement with the empirical thresholds calculated for lateral spread events observed in the 2003 Canberra bushfires. A theory to explain these environmental thresholds and their apparent interdependency is presented. The results are expected to have important implications for the management of wildland fires in rugged terrain.
The Mt Cook Station fire was ignited in 100% cured grass by a chainsaw on 16 January 2008. The fi... more The Mt Cook Station fire was ignited in 100% cured grass by a chainsaw on 16 January 2008. The fire was eventually controlled on 22 January, although mop-up of hot spots continued for several weeks. The fire burned 756 hectares, predominantly in dense stands of wilding conifers and light scrub, making it the largest wildland fire in the South Canterbury Rural Fire District for over a decade. Periods of high intensity fire behaviour were observed during the main fire runs in the dense wilding stands in the 24 hr period following ignition.
Blow-up fire behaviour can be broadly defined as a rapid escalation in the intensity or forward r... more Blow-up fire behaviour can be broadly defined as a rapid escalation in the intensity or forward rate of spread of a wildland fire, and is often accompanied by extreme pyro-convection associated with rapid smoke release and dispersion. Blow-up fire behaviour is difficult to predict and has been linked to firefighter fatalities, making it an important fire management hazard. compiled the first observational dataset of categorised wind speed and direction profiles associated with blow-up fire behaviour. Low-level jets, varying in height between 30 and 1000 m above ground level (AGL), are a common feature in Byram's wind-profile types. Additional studies have qualitatively discussed how low-level jets can influence wildland fire behaviour and pyro-convective plume dynamics. However, there has been little quantitative testing and analysis of the physical processes linking low-level jets and blow-up fire behaviour.
Recent work has demonstrated that under conditions of extreme fire weather, bushfires burning in ... more Recent work has demonstrated that under conditions of extreme fire weather, bushfires burning in rugged terrain can exhibit highly atypical patterns of propagation, which can have a dramatic effect on subsequent fire development. In particular, wildfires have been observed to spread laterally across steep, lee-facing slopes in a process that has been termed 'fire channelling'. Fire channelling, in turn, has been associated with serious escalation in fire activity and the development of pyrocumulonimbus storms. Coupled fire-atmosphere modelling using large eddy simulation has indicated that the fire channelling phenomenon occurs in response to fire-induced vorticity on the fire's flanks in the immediate lee of a ridge line. In this paper we extend previous modelling, using the WRF-Fire coupled fire-atmosphere model, to specifically consider the effect of wind speed in generating the fire-induced vorticity necessary to drive the lateral spread associated with fire channelling.
This study presents new knowledge of the environmental sensitivity of a dynamic mode of atypical ... more This study presents new knowledge of the environmental sensitivity of a dynamic mode of atypical wildland fire spread on steep lee-facing slopes. This is achieved through a series of idealized numerical simulations performed with the Weather Research and Forecasting (WRF) and WRF-Fire coupled atmosphere-fire models. The sensitivity of the atypical lateral fire spread across lee slopes is tested for a varying background wind speed, wind direction relative to the terrain aspect, and lee slope steepness. The results indicate that the lateral spread characteristics are highly sensitive to each of these environmental conditions, and there is a broad agreement with the empirical thresholds calculated for lateral spread events observed in the 2003 Canberra bushfires. A theory to explain these environmental thresholds and their apparent interdependency is presented. The results are expected to have important implications for the management of wildland fires in rugged terrain.