Scientists look to the Sun

26 March 2010


Scientists from Geoscience Australia will be watching changes to Earth's magnetic field over the coming few years with evidence that the Sun has begun its latest cycle of sunspot activity.

The most recent so called sunspot maximum occurred in 2000 and was followed by a period of decreasing sunspot numbers which was slightly longer than usual. However, scientists are now seeing evidence that the new solar cycle has begun and the number of sunspots may be starting to rise again. If the normal pattern continues they should peak around 2013.

Loops in the Sun's magnetic field which often are associated with sunspots. Photo courtesy: TRACE/NASA

Loops in the Sun's magnetic field
which often are associated with
sunspots.
Photo courtesy: TRACE/NASA.

One of the significant effects of sunspots and associated solar flares is the impact on Earth's magnetic field. The rapid field changes caused by sunspots affect satellite and high-frequency radio communications, telephones and powerlines. They also degrade the accuracy of GPS positions and disrupt magnetic surveying operations.

Another consequence of increased solar activity is auroral displays which are caused by charged particles from the Sun entering Earth's magnetic field and colliding with gas particles in the atmosphere. Auroras occur more commonly in polar regions, but the phenomenon can sometimes also be seen nearer the equator during periods of intense magnetic activity.

Working in conjunction with the Australian Space Weather Agency, IPS Radio and Space Services, Geoscience Australia will record any increased activity in Earth's magnetic field at its geomagnetic monitoring stations at Kakadu and Alice Springs in the Northern Territory, Learmonth and Gnangara in Western Australia, Charters Towers in Queensland, near Canberra in the ACT and in Antarctica at Casey, Mawson and Macquarie Island.

For more information visit Geoscience Australia's Geomagnetism Project.

Topic contact: media@ga.gov.au Last updated: October 4, 2013