An aerosol boomerang: rapid around-the-world transport of smoke from December 2006 Australia forest fires observed from space

We investigate rapid around-the-world transport of a smoke aerosol plume released by intense forest fires in southeastern Australia in December 2006. During the first half of December 2006, southeastern Australia suffered from severe drought and exceptionally high temperatures. On 14 December 2006, a passing cold front in combination with the intense heat from the firres causing pyro-convective lofting, injected a large mass of aerosol particles into the jet stream. We track the resulting aerosol plume using Aerosol Absorbing Index (AAI) observations from the Ozone Monitoring Instrument (OMI) and and that it circumnavigated the world in 12 days. Using observations from OMI and the CALIOP (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) spaceborne lidar, we show that the plume resided in the high troposphere at di®erent stages of its evolution. The observed two-dimensional evolution of the smoke aerosol plume and the vertical distribu-tion of the plume detected by CALIOP is matched by simulations with the TM4 chemistry transport model for an injection height of 250 hPa (»10 km). Injection heights at the surface and at 540 hPa (»5 km) resulted in simulated vertical distributions that were 2-3 km too low relative to CALIOP ob-
29 servations, and showed less agreement with the AAI patterns. The high injection altitude of 10 km mimics the effect of pyro-convective lofting as the additional buoyancy from the intense fires is not accounted for in the model.