Ocean study explores link with Australian rainfall

Jul 28, 2004

A five-nation oceanographic team is taking the first steps in a $3.6 million project studying the major flow of ocean currents between Asia and Australia and how they influence rainfall across Southern Australia and Indonesia.

Scientists are investigating fluctuations in the flow of warm waters from the western Pacific Ocean draining through the Indonesian Archipelago into the Indian Ocean north of Australia.

"Our climate, and particularly the amount of rainfall across the country, is regulated by the oceans around Australia," says CSIRO's Dr Susan Wijffels.

"Through new satellite and sub-surface technologies we are gradually building a picture of these key influences on rain-bearing cloud band systems in the eastern Indian Ocean. Over the next three years we hope to understand the variations that occur to the flow of currents including any effects of El Nino and La Nina events," Dr Wijffels says.

Dr Wijffels is co-leader of the project, called INSTANT. Sub-surface ocean monitoring equipment valued at more than $2 million has been moored at strategic 'choke' points across the entry of the currents into Indonesia waters, and their exit to the Indian Ocean through Lombok and Ombai Straits and Timor Passage.

Partially funded by the Australian Greenhouse Office and CSIRO, the array of tidal gauges and ocean moorings will sample pressures, currents, temperature and salinity and provide a record of changing conditions.

Dr Wijffels says the INSTANT science team, comprising US, French, Dutch and Indonesian scientists, has successfully deployed highly sophisticated measuring instruments in the straits from the Indonesian research vessels, Baruna Jaya I and VIII.

She says the data collected will be compared with simple models and computer simulations of the tropical oceans, and the way the oceans then interact with the atmosphere.

"The atmosphere is very sensitive to the distribution of warm waters near the equator. In our region two large warm water pools exist - in the Western Pacific and Eastern Indian Ocean.

"We believe the exchange of warm low salinity water between the Pacific and Indian Oceans through the Indonesian passages will yield critical information on how these two 'pools' of warm water in our region interact."

Dr Wijffels says it will be at least 18 months before scientists can retrieve the information obtained from the ocean instruments, which are sub-surface and will be serviced and redeployed by the INSTANT team using Indonesian ships in 2005.

Indonesian participation in the project will also have broad benefits, according to joint project Director, Dr Ir. Indroyono Soesilo, of the Indonesian Agency for Marine and Fisheries Research.

"Improved climate predictions will benefit many people living in areas affected by El Nino/La Nina and the Asian-Australian Monsoon," Dr Soesilo says.

"The Republic of Indonesia is strongly affected by these phenomena, and will be able to use the model projections to make informed management decisions regarding agricultural, water and fisheries resource issues and prepare for climate-related forest fires.

"Measurements of the way these waters mix in regions such as the Flores and Banda Seas will provide an important understanding of the processes that sustain fisheries stocks in these seas."

Dr Tony Haymet, Chief of CSIRO Marine Research, emphasises that the INSTANT team research is both an important international research project in its own right, and also a key step in the steady expansion of CSIRO's research with partners in the oceans north and west of Australia.

Australia has an extensive oceans and climate research program, particularly in the Indian and Southern Oceans, and participates in many international monitoring projects such as the global float array Argo.

Source: CSIRO

Explore further: Start of dwarf planet mission delayed after small mix-up

Related Stories

Hunting for living fossils in Indonesian waters

Mar 30, 2015

The Coelacanth (Latimeria menadoensis) was thought to be extinct for more than 60 million years and took the science world by storm in 1938 when it was re-discovered living in South Africa. This fish has ...

Good luck and the Chinese reverse global forest loss

Mar 30, 2015

Analysis of 20 years of satellite data has revealed the total amount of vegetation globally has increased by almost 4 billion tonnes of carbon since 2003. This is despite ongoing large-scale deforestation ...

Divers enter water in search of wreckage from AirAsia jet

Jan 07, 2015

At least two divers plunged into the choppy waters early Wednesday during a break in the bad weather to search for two large objects suspected of being chunks of the fuselage of the AirAsia plane that crashed ...

Recommended for you

The riddle of galactic thin–thick disk solved

Apr 24, 2015

A long-standing puzzle regarding the nature of disk galaxies has finally been solved by a team of astronomers led by Ivan Minchev from the Leibniz Institute for Astrophysics Potsdam (AIP), using state-of-the-art ...

Giant cosmic tsunami wakes up comatose galaxies

Apr 24, 2015

Galaxies are often found in clusters, with many 'red and dead' neighbours that stopped forming stars in the distant past. Now an international team of astronomers, led by Andra Stroe of Leiden Observatory ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.