Australia becoming drier, Antarctica colder due to Westerly winds speeding up

The Southern Annular Mode consists of Westerly winds that blow continuously over the southern ocean, helping to insulate the southern continent of Antarctica. In recent decades these winds have sped up and moved further south as a result of climate change. This results in drawing rain clouds to the south away from Australia particularly affecting Autumn and winter rainfall.

The Bureau of Meteorology has observed a long term trend for south-eastern and south western Australia becoming more dry. New research has identified reasons for this and why Antarctica has not experienced a warming trend like the rest of the planet.

Western Australia has suffered a 20 per cent loss in winter rainfall since the 1960s. South eastern Australia has suffered a 10 per cent reduction in winter rainfall from the 1990s.

Even during the back to back La Ninas in 2011 and 2012, the Drying trend in Australia still evident despite being the wettest two year period on record. But we have known for some time that Less rain across southern Australia is a long term climate trend due primarily to increasing atmospheric carbon dioxide concentrations increasing atmospheric temperatures thus changing the dynamic of the sub-tropical jet stream and thus the number and intensity of storms bringing autumn and winter rainfall to southern Australia.