The word "austral" is used to describe something that is related to the Southern Hemisphere or the countries located in the southern part of the world. Full definition
Matthewman, N. J., and G. Magnusdottir, 2012: Clarifying ambiguity in intraseasonal Southern Hemisphere climate modes during austral winter. (sites.uci.edu)
The rapid early reduction in sea ice cover in this region may create favorable conditions for the break up of the eastern Peninsula ice shelves at the end of austral summer. (nsidc.org)
The journey down the Carretera Austral began and ended with a boat ride. (theexpeditioner.com)