Jorge Newbery Airport, Buenos Aires (AEP)
Jorge Newbery (AEP) airport is the domestic airport in Buenos Aires. International flights come into the oher main airport in Buenos Aires, Ezeiza (EZE), so you'll need to travel between the two if you're flying into Patagonia via Buenos Aires.
Here you can find out more about the airports in Buenos Aires.
Map of Jorge Newbery Airport, Buenos Aires (AEP)