A 1,500 km latitudinal transect from Patagonia to the Antarctic Peninsula, sampled across a documented atmospheric-river event (Feb 7–8, 2022). Air, soil, and rhizosphere 16S/ITS combined with ERA5, HYSPLIT, and CHIMERE evidence show a phylogenetically broad, terrestrially-sourced bioaerosol plume reaching Risopatrón Base.