DROUGHT-BREAKING rains across eastern Australia have been predicted in new modelling by a scientist who believes massive pulses in the sun's magnetic field are helping to drive the Earth's climate systems.

If proven, the research will make the prediction of floods and droughts in Australia far more reliable and influence models projecting future climate change.

Robert Baker, from the University of New England, claims to have found a strong relationship between the rhythmic pulsing of the sun's magnetic field and weather systems, particularly in the southern hemisphere.

The sun's magnetic emissions are known to peak every 11 years, a phenomenon demonstrated by increased sunspot activity. The sun also switches poles every 11 years. It last flipped in 2001.

Associate Professor Baker said modelling of the sun's magnetic activity showed high rainfall during times of high activity and drought when the sun was stable.

This suggested the fluctuations impacted on the upper atmosphere, which was in turn reflected in changes in the Southern Oscillation Index (SOI), the measure of air pressure over the Pacific Ocean used as a reliable indicator of drought and flood.

Dr Baker said the most intense droughts in eastern Australia, including the Federation drought, tended to occur every 22 years, about a year after the southern pole of the sun flipped and became positively charged.

In a paper, which has been submitted to the journal Solar Terrestrial Physics for peer review, he claims changes in solar magnetic fields can explain about 50 per cent of the variation in the SOI.

The impact of solar magnetism is more noticeable in the southern hemisphere and in regions such as eastern Australia because more variable climate is driven by proximity to large oceans.

He said this relationship between the sun and climate required further research because it might help to explain an important but little understood natural cycle influencing the Earth's climate systems.

"The sun drives the whole system," he said. "There is a natural impact that the sun has in terms of weather patterns maybe over a century."

Dr Baker said the sun appeared to follow a longer-term magnetic cycle of about 80 years, meaning it might be possible to predict floods and droughts for the next 30 years based on historical records from the mid-1920s.

Dr Baker said the SOI was currently following a similar pattern to that recorded after 1924 when eastern Australia enjoyed heavy falls after a period of prolonged drought.

Dr Baker's model puts a more scientific and transparent theory to the concepts first developed by long-range weather forecasters Lennox Walker and Inigo Jones.

It also suggests there may be a longer 500-year solar cycle, which may help explain climate variability over the past centuries, including periods of unexplained climate variability such as the Medieval Warm Period and the Little Ice Age.

Dr Baker said he was concerned about the welfare of rural communities amid unfounded speculation the current drought might continue for decades.