Last updated October 10, 2018

Decrease in southeastern Australian water availability linked to ongoing Hadley cell expansion

  • States that southeastern Australia experienced the worst drought of the instrumental record from 1997 to 2009, which was broken by Australia's wettest 2 year period on record (2010/2011)
  • States the drought was primarily a cool season (April to October) phenomenon, while the breaking of the drought was a warm season (November to March) phenomenon
  • Finds this reduction in winter rainfall along with an absence of very wet months led to a greater reduction in streamflow across the region than would be anticipated based on the 12% reduction in mean annual rainfall alone
  • Results link the extent, duration, and severity of this drought to the ongoing observed expansion of the Southern Hemisphere Hadley cell at a rate of 0.5°/decade
  • Finds this expansion has intensified the subtropical ridge over southern Australia, pushing cool season midlatitude storm tracks further south, leading to a reduction in winter rainfall and runoff across the region