Bulletin

Issue: November/December 2006

Research in Action

Keeping a better eye on space weather

Two La Trobe University students have helped develop new scientific equipment for Australia’s Mawson Antarctic Base that will greatly speed up a critical aspect of atmospheric research.

Mr Anderson, left, Ms Sammut and
Dr Conde conduct final trials at the
University before the instrument
is shipped to Antarctica.

The equipment will make a significant contribution to understanding the effects of space weather on communications, navigation, surveillance capability, and the operation of low altitude satellites, according to its designer, space physicist, Dr Mark Conde.

The new Fabry-Perot Spectrometer, built in the University’s Physics Department workshop, will replace an existing one at the Mawson Base. It underwent final trials on the University’s main Melbourne campus at Bundoora in October, prior to being shipped to Antarctica in November.

The two students involved are Callum Anderson - a PhD researcher who developed the software to control the instrument and who will operate it in Antarctica - and Letizia Sammut, an Honours student responsible for testing and calibrating aspects of the instrument.

Mr Anderson recently completed his Antarctic expeditioner training in Hobart. He will be one of 28 people at the Mawson Base this summer and, for an extended challenge, one of 14 to remain there the whole winter.

Dr Conde, a senior lecturer, and Professor Peter Dyson, Head of the Physics Department, developed the imaging spectrometer over the past three years with the help of a $335,000 ARC Discovery grant. It was built by Mr Eric Huwald and Mr Habib Rahman in the Physics Department’s technical workshop.

Research Fellow, Mr Theo Davies who worked with Dr Conde and Professor Dyson on the spectrometer, will also go to Mawson for the summer to help install the instrument and check on another La Trobe instrument at the Davis Base. Dr Conde says the new device will be used to observe the very top layers of Earth’s atmosphere, measuring shifts in the wavelength of light as it passes through gases in this region.

This data is used to calculate wind and temperature disturbances as the atmosphere is buffeted by eruptions from the Sun - the solar wind. Depending on their intensity and location, these disturbances can interfere with navigation, communication and other equipment - especially at the high latitudes of Antarctica.

Optical remote sensing obtains a closeup picture of wind patterns at an altitude that previously has been in the space weatherman’s ‘too hard basket’: too high for aircraft or balloon observations, and too low for orbiting satellites.

Aircraft and balloons, says Dr Conde, are effective for probing up to about 50 kms, and satellites for measurements down to about 400 kms above the Earth’s surface. Which leaves radar, and optical remote sensing systems such as this new equipment, to study the area in between. La Trobe has long been recognised for its research in this region of the atmosphere using both these systems, see below.

The University’s research in Antarctica using radio, magnetic and optical remote sensing goes back to the 1960s. About 15 students and staff have taken part in scientific expeditions to the frozen continent during that time.

Dr Conde explains the new spectrometer is a major improvement on the first generation of optical remote sensing instruments, which have operated since the 1970s, and are in some cases still being used. These older instruments have small telescopes that need to focus on one part of the sky for about ten minutes to gather sufficient airglow data.

“Using a fish-eye lens, the new instrument can observe the entire sky simultaneously, mapping wind and temperature variations across 1,000 km in diameter. Coupled with vastly superior computerised image processing, it examines about 40 to 50 regions in the sky at once, from 20 degrees above the horizon to the zenith. This is a huge increase in capacity and ushers in a new era of optical remote sensing research.”