Transport of Patagonian dust to Antarctica

The transport of Patagonian dust to Antarctica is investigated by using the Geophysical Fluid Dynamics Laboratory Atmospheric Model with online aerosol, in combination with trajectory analysis and satellite observations. The southern coastal region of northern Patagonia and the San Julian's Great depression are identified as major sources in Patagonia. Trajectory analysis indicates that only 13%-20% of air masses from Patagonia reach Antarctica within 10 days, with 1/4 and 3/4 going to West and East Antarctica, respectively. Almost twice as many trajectories from the San Julian's Great Depression reach Antarctica compared to the more northern Patagonian source. It takes ∼7 days for Patagonian dust to be transported to East Antarctica, and 4-5 days to West Antarctica. The transport to East Antarctica is driven by the low-pressure systems moving eastward in the subpolar low-pressure zone, whereas a dust event going directly southward to West Antarctica typically happens when a high-pressure system blocks the depressions moving through the Drake Passage. Demonstrating these features, respectively, by following the journey of two typical dust plumes from Patagonia to East and West Antarctica, this study clarifies how climatic factors may affect the amount of dust reaching the Antarctic surface.