Summary
As revealed by the CALIPSO orbiting lidar, the intense firestorms that occurred in southern Australia during February 2009 injected a significant plume of smoke particles into the lower stratosphere. Over the following weeks, the stratospheric smoke dispersed to high southern latitudes and became visible to lidars operating in Antarctica as laminated layers of enhanced aerosol backscatter at altitudes up to 20 km. The determination of the physical evolution of the smoke particles is important for evaluating impacts on chemistry and climate in the polar stratosphere. In this paper we present preliminary analysis of characteristics of the smoke aerosols using the ‘match’ approach. Our analysis has been developed for the ORACLE-O3 International Polar Year project to investigate the evolution of Polar Stratospheric Clouds. In essence, our approach uses trajectory analysis to follow air parcels in the lower stratosphere and determine times when they intercept the measurement fields of the CALIPSO satellite and ground-based aerosol lidars. The properties of the aerosols are evaluated from their scattering and depolarisation behaviour at specific laser wavelengths. We compare the evolution of the aerosol properties extracted from the lidar measurements sampled with trajectory models that are driven by different meteorological assimilations and physical advection schemes, under the assumption that the aerosols are weakly sedimenting. This allows us to place limits on vertical advection and examine the accuracy of the trajectory models. We also investigate the influence of temperature on the characteristics of the aging aerosols.