Thursday, 4 October 2007

MEDIA RELEASE

Tracking the monsoon using models

Climate scientists are studying a better way of researching changes to the pattern of the monsoon season that is so critical to northern Australia.

The monsoon is an important climate feature for those living in the tropics and plays a crucial role as a regular source of rain for water-supplies in Australia's north.

Global climate models have traditionally had difficulty in simulating the state of the climate in tropical regions and there have been various attempts to use large-scale information from such models as a way to capture features of the monsoon system behaviour.

By comparing daily observational data with a range of different climate models, Dr Aurel Moise and Dr Huqiang Zhang from the Bureau of Meteorology have found that it is now possible to compare the behaviour of the observed monsoon system from the 20th Century with that simulated by computer models. By measuring the amount of available moisture in the air in different wind fields, researchers believe that changes in some of the monsoon characteristics under climate change conditions can now be studied.

Bureau researchers have been investigating the most recent simulations from coupled global climate models to see what they can infer about the onset and timing of the Australian monsoon in research presented as part of the GREENHOUSE 2007 Conference.

Australia's monsoon is at the sensitive southern edge of a larger Asian-Australian monsoon system that shifts seasonally between the northern and southern hemisphere tropical regions, bringing the typical wet season rain.

"Diagnosing the reliability of climate models to predict the behaviour of the monsoon is very useful for us. What we are trying to do is to determine whether there is a climate change signal that can be detected through the naturally varying behaviour of the monsoon," said Dr Aurel Moise from the Bureau of Meteorology.