Seasonality: The anthropogenic South American Plume (SAP) exists from August to October each year at significantly varying levels of intensity.
Sources Anthropogenic: The SAP is nearly exclusively derived from biomass burning linked to land clearing and agriculture plus a few gas flares in the oil production industry identified by the World Bank Global Gas Flaring Reduction Partnership and NOAA.
Sources Natural: Occasionally natural aerosols from volcanoes along the Andean mountain chain contribute to the plume.
Trajectory: The SAP is constrained by the high Andes to the west and typically exits to the south east towards the southern ocean.
Most Extreme: September 2007 was the most extreme apparition of the SAP in the Terra satellite data when it exhibited a maximum aerosol optical depth of 2.25 at its centre.
Effects: My paper presented at the AGU Fall Meeting in 2015 shows how the SAP causes drought in the Amazon basin.