Ocean robots watching our climate

A new array of ocean robots has begun working deep in the Indian Ocean to help scientists understand Australia’s changing climate.

“This is a key region for the global climate system and installation of the robots will provide our best coverage to begin to understand how the Indian Ocean affects our climate,” says CSIRO’s Dr Gary Meyers.

Cycling between the surface and a depth of two kilometres every 10 days, the ocean robots are sampling conditions in a region thought to be a source of southern Australian rainfall.

“We want to understand the mechanism of so-called ’northwest cloud bands’ and the possibility that subsurface ocean conditions control how frequently they form,” Dr Meyers said.

CSIRO and the Bureau of Meteorology will have 19 new Argo ocean robots in place by Christmas, completing an array of profiling floats extending from Indonesia to Cape Leeuwin in Western Australia, as the Australian contribution in an international effort to observe the world’s oceans.

Nearly 600 of the ocean profilers have been deployed globally with 3,000 profilers due in place by 2006.

The information collected by the robots about water temperature, salinity and ocean currents is sent via satellite to ground stations and to research organisations.

“This is a key region for the global climate system and the instrument placements will provide our best coverage to begin to understand how the Indian Ocean affects climate in our region, says Dr Meyers.”

He was speaking following an international conference in Mauritius to shape development of the Indian Ocean Observing System. Dr Meyers convened the climate sessions.

The conference was called to identify the needs of, and potential contributions to an ocean monitoring program benefitting all the countries around the Indian Ocean rim.

The Argo robotic floats may ultimately form part of a larger monitoring program to uncover the role that the Indian Ocean plays in the monsoons of the continents of Africa, Asia and Australia.

“Improved climate prediction for the nations around the Indian Ocean would impact on the lives of almost two thirds of the world’s population,” says Dr Meyers.

In addition to floats, participants at the conference planned an integrated observing system that utilises data collected by moored and drifting instruments, merchant ships and satellites, and combines the different data types in a computer-generated ocean state estimation.

“There was tremendous enthusiasm from all the country-representatives to develop a basin-wide ocean monitoring system as the basis of a predictive system for understanding climate change, for identifying impacts on the marine environment and for prediction of rainfall variability.

“The benefits begin with basic regional climate research but have substantial environmental, economic and social implications,” Dr Meyers said.

Two of Australia’s major partnerships in ocean-observation were represented at the conference. The Indonesian Agency for Ocean Research and Fisheries (BRKP) is also assisting with regional float deployments, with the help of the Darwin-based commercial shipping industry, Perkins.

The Australia-United States Climate Action Partnership announced in February, 2002 by Environment Minister Dr David Kemp facilitates international cooperation on climate change issues. The partnership is focused on practical emission reduction activities, and exchange of scientific expertise, technology and innovation that offer mutual benefits to the two countries.