Bulletin

Issue: January/February 2006

Research in action

Space weather storms – How they affect Australia

La Trobe University’s leading role in space weather research – particularly on the effect of space weather storms – received a further lift recently with an ARC Discovery Grant to study energy deposition from solar winds.

The head of La Trobe’s Space Physics Group, Professor Peter Dyson, and two colleagues from Newcastle University, Associate Professor Frederick Menk and Dr Colin Waters, received $383,000 over three years.

The funds will help them to pursue research using the newly completed Tasman International Geospace Environment Radar (TIGER), an important Australian contribution to space physics, facilitating research and providing services for studies into space physics and space weather.

La Trobe’s Physics and Electronic Engineering Departments operate TIGER on behalf of a consortium of universities, government departments and commercial firms. TIGER includes a 300 metre long antenna installed on Bruny Island, Tasmania in 1999, and a similar one which began operation near Invercargill, NZ, in February last year.

The new grant will help fund the first research using the network created by combining the two antennae.

Professor Dyson said the expanded capacity of TIGER will be used to study complexities of energy deposition from the solar wind into Earth’s magnetosphere-ionosphere system.

He said TIGER will help map structures in the ionosphere and track their motion. A variety of processes such as reconnection between geomagnetic and interplanetary field lines, ultra-low frequency waves, and momentum transfer will be studied.

The objective is to identify the processes that produce phenomena that are currently not well understood, such as aspects of magnetic sub-storms and the transfer of energy from the auroral zone to lower latitudes.

The research will concentrate on the region on the equator side of the aurora that rings each polar region, looking at what drives changes in the upper atmosphere which occur during magnetic storms which affect solar wind so that region expands and contracts.

‘We need to know how far the aurora expands towards the equator and what its characteristics are in order to understand the whole thing,’ Professor Dyson said.

‘Our interest is the fundamental physics but the practical applications of being able to predict space weather are very important. Australia has a government department, IPS Radio and Space Services, whose job is to do that because it impacts, for example, on communications in a number of areas,’ he said.

Benefits of the research will include improved ability to observe, understand and predict space weather impacts on Australia’s communications, navigation, and surveillance capabilities. These include communications with aircraft, GPS navigation, and prospecting using magnetic techniques.

It will also support specific Australian programs such as the JORN, the over-the-horizon radar coastal surveillance system, and space weather monitoring activities.

‘In addition it will continue to provide Australia with a central role in the multi-nation SuperDARN project that continues to pioneer new initiatives in successful radar network operations for scientific studies and for the development of space weather data products for monitoring agencies and other scientists.

‘This is the first grant we have had to do science with the two radars operating fully. TIGER’s capability is now greatly enhanced with each radar emitting beams that cross, giving different line of sight velocities that can be combined to provide accurate “vector” velocities of motions in the highly disturbed auroral ionosphere,’ Professor Dyson concluded.