Links between the sun's magnetic pulse and Earth's climatic systems point to heavy rainfall later this year and in 2008, which could break Australia's worst drought in 100 years, new scientific research says. The theory, which has been submitted for publication in the journal Solar Terrestrial Physics, is based on correlations between Australian rainfall and 11-year peaks in the sun's magnetic emissions, and switches in the sun's poles, which also occur every 11 years. The last flip occurred in 2001.

"The sun is now in a similar position in terms of its magnetic field as it was in the 1920s," Associated Professor Robert Baker of the University of New England said. Eastern Australia this year and next is seen following a similar path to the particularly wet years of 1924 and 1925. "If it keeps tracking...we would therefore expect average and above rainfall for eastern Australia," Baker said. "The sunspots are starting to increase again and as it increases over the year historically that's been a time of above average rainfall," he said. According to Baker's theory, 2009 would be the next period of potential drought in Australia.

Baker produced his theory from work on physical models of sunspot behaviour, which showed correlations between sunspot minimums and eastern Australian droughts over the last 100 years. "It just went from there... It's just asking good questions." Baker says that weather effects of changes in the sun are additional to the impact of "flavour of the month" climate change from greenhouse gases. The theory opens the way for better predictions of droughts and floods, Baker said.

After the present cycle of increased sunspot activity, the following cycle will be dominated by the lowest activity from sunspots and magnetic activity in 100 years. This raised the possibility of widespread drought again, in the 2020s. "The last time that happened was the Federation Drought of around 1900," Baker said. The link between sunspots, solar magnetic activity and increased rain occurs through interaction by solar activity with Earth's atmosphere to increase cloud formation.

In following established patterns of pulses in the sun, the theory is hoped to lead to increased forecasting certainty and management of water resources.
(Planet Ark, 20/03/2007)