Serious rainfall decreases in south-western Western Australia since the 1970s could have profound implications for the rest of Australia.
Researchers from CSIRO and the Bureau of Meteorology are trying to identify the causes of south-west WA's continuing 'dry'.
They hope to use their findings to better estimate what may happen in coming decades.
"Water supply authorities and agencies designing new water catchments need to know whether south-western Western Australia will stay relatively dry, become drier, or return to pre-1970s' conditions," says Dr Ian Smith, from CSIRO Atmospheric Research.
"We are studying a unique corner of Australia and exploring climatic fluctuations that happen from decade to decade and even over centuries," says Dr Smith.
"Most parts of Australia are affected by climatic ups and downs. People are always asking, 'has climate changed permanently, or is this just a temporary change?' Our research is working to answer this in a part of the country where the question is vitally important."
Rainfall decreases in south-western Western Australia over past decades have coincided with warming of surface waters of the southern Indian Ocean and with fewer low pressure systems in the area.
If the changes observed in south-western Western Australia are part of a continuing, broader climatic shift, researchers say that it may affect other parts of Australia.
"Changes of this sort are most likely due to long-term natural climatic variations," says Dr Smith. "In the case of south-western Western Australia, other factors could be contributing to the drying trend, such as the greenhouse effect. Local or global land-use changes may also be factors."
"Unfortunately, over the next century the greenhouse effect is likely to cause further drying in south-western Western Australia," says Dr Smith.
The Indian Ocean Climate Initiative involving CSIRO and the Bureau of Meteorology is funded by the Western Australian Government.
Source:
http://datamining.csiro.au/files/mediaRelease/mr2001/Prwadry.htm
