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A pressure gradient metric capturing planetary-scale influences on eastern Australian rainfall


Rakich, CS and Holbrook, NJ and Timbal, B, A pressure gradient metric capturing planetary-scale influences on eastern Australian rainfall, Geophysical Research Letters, 35, (8) pp. L08713. ISSN 0094-8276 (2008) [Refereed Article]

DOI: doi:10.1029/2007GL032970


The Gayndah-Deniliquin index (GDI), a measure of the north-south atmospheric pressure gradient across eastern Australia, is presented. The 113 year long GDI record reveals strong interannual to decadal scale variability in zonal geostrophic wind flow across eastern Australia. The GDI, as a measure of easterly geostrophic wind strength and associated moisture transport from the Pacific Ocean, is shown to be significantly correlated with summer rainfall over vast areas of the Australian continent, especially over the Murray Darling Basin and the state of New South Wales. The latest abrupt decline in the GDI, which commenced around 2001, corresponded with the onset of a severe prolonged drought across eastern Australia. We demonstrate that the northern and southern poles of the MSLP derived GDI are differentially influenced by El Niño-Southern Oscillation (ENSO) and the Southern Annular Mode (SAM). Understanding the effects of these interactions between SAM and ENSO on moisture transport to eastern Australia could have implications for future Australian climate variability and climate change. Copyright 2008 by the American Geophysical Union.

Item Details

Item Type:Refereed Article
Research Division:Earth Sciences
Research Group:Oceanography
Research Field:Physical oceanography
Objective Division:Environmental Policy, Climate Change and Natural Hazards
Objective Group:Adaptation to climate change
Objective Field:Social impacts of climate change and variability
UTAS Author:Holbrook, NJ (Professor Neil Holbrook)
ID Code:52571
Year Published:2008
Web of Science® Times Cited:28
Deposited By:Geography and Environmental Studies
Deposited On:2008-08-01
Last Modified:2015-02-05

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