Australian dust paths (1965 - 2014)

Tyler Kelly 1, Matthew Baddock2, Tadhg O'Loingsigh1, Craig Strong3, Grant McTainsh1
1School of Environment, Griffith University, Brisbane, QLD, Australia, 2Department of Geography, Loughborough University, Leicestershire, UK, 3The Fenner School of Environment & Society, The Australian National University, Canberra, ACT, Australia

 Early studies of dust transport paths within and beyond the Australian continent identified two major dust paths; the South-east and North-west dust paths. The South-east dust path was generally thought to pass across the southern half of the continent and exit over the southern Tasman Sea, then over New Zealand. The North-west dust path was believed to originate from central Australia, passing off the West Australian coast between Port Hedland and Broome, where the Great Sandy Desert meets the Indian Ocean.

 In more recent times, a number of event-based dust storm studies using meteorological records of dust and remote sensing have shown that the dust plumes sometimes pass beyond the limits of the South-east dust path. The North-west dust path has been less well studied, but indications are that this may also be more complex than previously described. To date, insufficient evidence has been provided of the consistency of these dust plume trajectories, to allow them to be designated as new dust paths. Simulated airflow trajectories using the HYSPLIT model (Hybrid Single Particle Lagrangian Integrated Trajectory) have provided useful climatologies of the directionality, transport distances and seasonality of potential dust paths, but explicit linkages have not yet been made between these trajectories and actual dust events.

 In the present paper we present a 50-year climatology of Australian dust transport paths, using meteorological records to identify dust event occurrence and HYSPLIT to simulate dust transport directions and distances. Our results show that the South-east dust path is actually one of three passing off the east coast of Australia, including; a South-south-east dust path, the South-east dust path and a North-east dust path. The North-west dust path will also be shown to be much more complex; with dust feeding into it from the south (in near-coastal Western Australia), the south-east (in central Australia) and the east (across northern Australia).