Scientists are set to conduct high resolution ground-space measurements of Earth’s magnetic field above Antarctica using a magnetometer on board the Australian polar orbiting micro-satellite, FedSat, and magnetometers in Antarctica. This represents a significant enhancement of the role of the Antarctic ground-magnetometer array from the summer of 2002–03.
On 14 December 2002, the 58kg FedSat, Australia’s first scientific micro satellite, was launched from the NASDA/JAXA Tanegashima Space Centre in southern Japan and placed in an 800km altitude Sun-synchronous polar orbit with a 100 minute period. The primary scientific payload on FedSat is Newmag, a fluxgate magnetometer experiment built by the University of Newcastle as its contribution to the Australian Cooperative Research Centre for Satellite Systems. Fedsat and Newmag will enable the first Australian based ground-satellite investigation of magnetic pulsations and current systems over Antarctica.
For the past several years two Narod fluxgate magnetometers have been deployed at sites about 110km inland from Australia’s Davis and China’s Zhongshan stations to form a square array of magnetometers. Permanent induction magnetometers have been operating at Davis since 1981 and at Zhongshan since 1992 under the auspices of an international collaboration between the University of Newcastle, the Polar Research Institute of China, and the Australian Antarctic Division. The summer deployments have been made by helicopter.
The Narod magnetometer systems, also developed by the University of Newcastle space physics group, are housed in boxes, sealed against drift snow, and connected to the magnetometer head via a 60m cable. Power is supplied by battery coupled to a solar panel secured on the snow to prevent damage during blizzards, and hopefully to prevent it being buried. During the deployment and subsequent visits to download data, local weather conditions were typically at temperatures near minus 20°C with drifting snow at 15 knots.
The plateau magnetometers were designed for summer deployment with retrieval scheduled some six weeks later, but the units were redeployed in the field at the end of the summer to extend the ground observations for comparison with the Fedsat magnetometer. The 2003–04 summer retrieval revealed that the Narod has coped with the winter conditions, collecting six weeks of bonus data on the palmtop computers. This program will continue for the duration of the FedSat mission.
Several visits to the Chinese station Zhongshan were needed throughout the summer to replace a GPS clock, computer, and to conduct the annual magnetometer calibrations prior to the summer campaign commencement. On all occasions our Chinese colleagues were excellent hosts providing our every need and much more. We shared a common goal and spirit that comes naturally to Antarctic expeditioners working for science and international goodwill.
The FedSat and Antarctic magnetometers will provide a unique data set for Newcastle University and AAD scientists for their continuing study of polar cusp region magnetic pulsations (waves with periods ranging from parts of a second to several minutes with varying amplitudes). The polar cusp is the region between the last closed magnetic field lines and first open magnetic field lines typically located in the upper atmosphere above Davis and Zhongshan.
Observations beneath this magnetic funnel allow us to monitor processes associated with the coupling between the Sun’s and Earth’s magnetic fields — similar to two bar magnets connecting or repelling each other — and the subsequent entry of solar particles into the Earth’s magnetic envelope and upper atmosphere. Such studies are important for our ability to forecast the conditions of our space weather environment. They contribute practical information to help mitigate damage to both ground-based technologies (electricity production, radio communication, pipeline corrosion) and space-based technologies (satellite electronics, astronaut health, satellite and mobile phone links).
We acknowledge the special contribution of Ward Bremmers, John Gordon, Doug Watts and Jeremy Crawford (Helicopter Resources) for providing excellent helicopter support for this project, and Jeremy Smith (Station Leader, Davis 2003) for coordinating our flight schedule. Thanks are also due to David Mitchell, Lloyd Symons and Richard Groncki for their organisation and technical work, and to the field support team including Paul Saxby, Meredith Nation, Alan Taylor, Danny Ratcliffe, Chris Heath, Ian MacLean and Mark Maxwell. University of Newcastle support was provided by Michael Terkildsen, Andrew Bish and Peter McNabb in the field and with instrumentation, and Fred Menk and Colin Waters with scientific contributions.
Ray Morris, Space and Atmospheric Sciences Program, AAD & Brian Fraser, University of Newcastle