Fire Research Directions Meeting 13 May 2009 Rapporteur Notes Session 4 Emissions and transport- Mick Meyer ACCESS modelling directions- Kamal Puri Coupled fire/atmosphere modelling- Michael Reeder

Emissions and Transport- Mick Meyer Bushfires impact on human health through air pollution exposure is substantial and needs to considered in forward planning, project setting and funding/capacity support. Example: Melbourne 2007 Summer. 6-7 plume strikes from bushfires. Probably a % ( people) increase in mortality from causes PM10 exposure. Similar to the number of deaths from direct fire exposure on Black Saturday. CSIRO Climate and Atmosphere currently working on ~$2M of projects related to bushfires-CO 2 emission accounting; regional aq impacts of prescribed burning; mercury sources and transport; dioxins and persistent organic pollutants; air quality and climate change; smoke impacts in Tasmania. Information gaps include- characteristics of the Australian bushfire aerosol, quantifying emissions (CO 2, PM and gaseous pollutants), smoke dispersion- plume rise; model performance. CAWCR (and partners) have the skill sets to research bushfire impacts over all of the relevant spatial scales {hemispheric to bushfire propagation [O(1m)]} Medium to long term objectives- improving emission algorithms (CO 2, aerosols + gaseous pollutants); use of remote sensing to better define source and plume characteristics; improved coupling between emission and transport models; identifying readily measured smoke tracer species; smoke impacts under climate change. An emergency response project has been submitted for the next Bushfire CRC bid. ACCESS- Kamal Puri ACCESS NWP testing is going very well with large improvements in skill scores compared to LAPS. Most of this improvement is due to the use of the 4DVAR scheme for initialising the forecast. Examples were given for cyclone forecasting and also for Black Saturday. Availability of the new supercomputer will enable the NWP to be run operationally at higher resolutions.

ACCESS- Kamal Puri (cont) ACCESS is a seamless prediction system and thus should be applicable to modelling bushfire meteorology at higher spatial scales (down to 100s of metres). However this would require a good high resolution observation data set for model initialisation. Rapid updating of the analysis would be useful during bushfire events. Accurate initialisation of soil moisture is critical. Also need to develop outputs of fire weather diagnostics and formats suitable for downstream applications ECMWF has some good examples of diagnostics- the use of ensembles to generate extreme weather indexes (Kamal shows an example for the 2009 February heat wave). It was suggested that the capability is set up to run ACCESS at high resolution for forecast extreme fire risk days + generate bushfire products for our clients (forecasters; fire services). Graham Mills asked about doing a re-analysis for the Australian region and noted how useful this would be for studying bushfire weather. Bob Cechet asked why model development wasn’t funding in the last CRC cycle. Coupled fire/atmospheric modelling- Michael Reeder. Bushfire weather research needs to consider all relevant spatial scales. At the hemispheric scale it is suggested that enhanced Rossby Wave breaking is a signature of all large bushfire events in Australia. John Bally noted the need to distinguish between normal wave breaking- which is common and the enhanced wave breaking identified by Michael. If this relationship is robust then it would be very interesting to investigate such events in (say) the ACCESS AMIP runs. A contributor to extreme heat waves/fire weather potential is likely to be extreme soil dryness, ultra low dewpoint temperatures and possibly vertical heat transfer through deep convection. A high-resolution (dx=100m) meteorological simulation was shown of the cold change propagation over the Dandenongs on Black Saturday and demonstrated the complexity of the interactions between the front and the local topography.

Coupled fire/atmospheric modelling- Michael Reeder (cont). A sensitivity study examined the interaction between a fire plume and the meteorology for the frontal simulation and found that the weather (at least at 100 m grid spacing) was insensitive to the fire plume. On the other hand, a high resolution modelling example based on the Canberra fires showed a much stronger interaction, with fire-cloud formation leading to Tornadogenesis. Very high resolution (dx = 1 m) modelling of fire propagation behaviour showed strong coupling between the fire plume and meteorology. However it was concluded that even higher resolution modelling would be required to fully resolve the coupling. John Bally asked if a such a fire propagation model could be run operationally during fire events. However this is currently not practical for both computational and initialisation reasons. A better approach would be to simulate a range of potential scenarios and to then draw on these scenario results during a bushfire event. John McBride emphasized the need for CAWCR and partners to undertake more research in this area.