Open AccessDecrease in southeastern Australian water availability linked to ongoing Hadley cell expansion
Author(s) -
Post David A.,
Timbal Bertrand,
Chiew Francis H. S.,
Hendon Harry H.,
Nguyen Hahn,
Moran Rae
Publication year - 2014
Publication title -
earth's future
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.641
H-Index - 39
ISSN - 2328-4277
DOI - 10.1002/2013ef000194
Subject(s) - southern hemisphere , storm , hadley cell , climatology , environmental science , subtropics , middle latitudes , ridge , growing season , geography , climate change , geology , oceanography , general circulation model , ecology , meteorology , biology , cartography
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). This drought was primarily a cool season (April to October) phenomenon. In contrast, the breaking of the drought was a warm season (November to March) phenomenon. 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. The results presented in this article have linked 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. 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.