A weather map presenting a typical India Ocean Dipole

Representation of a typical Indian Ocean Dipole and how sustained high pressure and easterly anomalies (arrows) across subtropical WA are partly explained as the response to variability over the tropics via atmospheric teleconnection. (CSIRO)

Warming Indian Ocean – impacts to be discussed

Reference: 10/32

The impacts of a warming Indian Ocean on Western Australia’s climate, environment and fisheries will be discussed today in Perth by scientists at a Western Australian Marine Science Institution (WAMSI) symposium.

  • 25 March 2010

A focus area of the discussions will be on understanding and forecasting the Indian Ocean Dipole (IOD) – a climate pattern in the Indian Ocean associated with a basin-wide shift in sea temperatures, winds and rain.

According to Dr Ming Feng – a CSIRO Wealth from Oceans Flagship oceanographer who is collaborating with the WA Department of Fisheries to understand climate variability and change impacts on fisheries recruitments in WA – researchers already know that remote climate influences from the Pacific Ocean have a large effect on the marine environment, the regional climate off the west coast of WA, and some of WA’s most valuable fisheries.

“But our understanding of how climate influences in the Indian Ocean affect the WA environment and fisheries is still relatively primitive,” Dr Feng says.

“In our WAMSI projects, we are looking to improve our forecast models of climate anomalies and future climate projections under enhanced greenhouse gasses in the atmosphere.This will help us better understand the link between variability of the ocean currents and fisheries recruitments, particularly the Western Rock Lobster fishery.

“We’ve been using numerical models that simulate the Leeuwin Current and shelf circulation so we can investigate whether a string of poor puerulus (juvenile) Western Rock Lobster settlement levels may be linked to IOD events.”

“In our WAMSI projects, we are looking to improve our forecast models of climate anomalies and future climate projections under enhanced greenhouse gasses in the atmosphere.”
Dr Ming Feng

The team has found that during IOD events, weakened westerly winds in late winter are evident, which may not facilitate the larvae returning to the coast.

“There’s also a possible link between IOD events and reduced storm activities off the south-west coast. And our model results show that the Leeuwin Current may increase in strength the year after a dipole event,” Dr Feng says.

According to the WA Department of Fisheries’ Dr Nick Caputi; “With the WA fisheries worth more than $400 million per annum, of which the Western Rock Lobster is among the top three contributors, improving our understanding of Indian Ocean currents and their influences is of vital importance.”

The Indian Ocean plays an important role in a warming world, as CSIRO scientists have identified that sea surface temperatures in the tropical Indian Ocean have risen relatively faster in recent decades with increases of sea surface temperature between 0.6 and one degree seen around the WA coast in the past 50 years.

These findings and a diverse range of Western Australian marine science will be discussed during the one-day symposium, to be held at CSIRO in Floreat. The WAMSI symposium is hosted by CSIRO’s Wealth from Oceans Flagship, the Bureau of Meteorology and the Australian Institute of Marine Science.

National Research Flagships

CSIRO initiated the National Research Flagships to provide science-based solutions to Australia’s major research challenges and opportunities. The 10 Flagships form multidisciplinary teams with industry and the research community.

The Western Australian Marine Science Institution (WAMSI) is providing a better scientific understanding of the marine environment for the people of Western Australia. It is a collaboration between 15 core partners, including Commonwealth and WA Government research organisations, universities and the private sectorWestern Australian Marine Science Institution

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