Nuclear science on Antarctic climate change mission

Two scientists from the Australian Nuclear Science and Technology Organisation (ANSTO) left for Antarctica earlier this week in search of byproducts of cosmic rays colliding with Earth. Senior Principal Research Scientist Dr Andrew Smith and Postdoctoral Research Fellow Dr Ulla Heikkila are on an environmental mission, working to discover whether a historical relationship exists between solar activity on the sun and climate change on Earth.

Dr Andrew Smith on a previous Antarctic trip, in 2005.

While solar activity is widely accepted to have only had a minor role in climate change over the past century, over longer periods it’s possible it had a much more significant role. For example, during the Maunder Minimum, between 1645 and 1715 AD, few sunspots were observed on the sun. This coincided with ‘The Little Ice Age’ on Earth.

The scientists departed on Tuesday on a nine-day mission to the summit of Law Dome, Antarctica. They are searching for beryllium-7 and beryllium-10, created when cosmic rays, thought to originate from distant supernovas, lose energy in Earth’s atmosphere. The men will bring back samples to ANSTO for analysis at the atomic level, using tools that allow scientists to detect individual beryllium-7 and beryllium-10 atoms in the ice.

“The key to predicting future climate change is understanding the factors that impacted on past climate change,” Dr Smith said. “There is some speculation that over the past thousands of years, solar activity may have had a significant impact on the climate of Earth, and that’s what we are researching.

“Research of isotopes over long timescales can help us understand whether there was a relationship, and whether the variability of the sun has a direct effect on global temperatures.

“Satellites and neutron monitors can provide data on solar activity for the last 50 years or so, and prior to that we have the sunspot record that began after Galileo invented the telescope. But it’s through going to Antarctica and bringing back samples of beryllium that we can get a real indication of how solar activity has affected Earth’s climate over past millennia.”

ANSTO’s nuclear techniques, including accelerator mass spectrometry (AMS), enable study of the roles of natural variability and human impacts on water, air and earth systems.

ANSTO’s environmental research specialisation includes areas of fine particle pollution, glacial and sedimentary systems, ice sheets and oceans.

This is Andrew Smith’s third trip to Antarctica to research the historical relationship between solar activity and climate change. This latest mission concludes on 15 February 2012.