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Looking for cloud seeding chemicals in Antarctic sea ice


Zoe Satherley
8 October 2007
Associate Professor Graham Jones, Director of the Centre for Regional Climate Change Studies at Southern Cross University, has won a $408,000 research grant from the Australian Antarctic Research Committee to investigate cloud seeding chemicals in the Antarctic sea ice.

The chemicals are produced by sea ice algae and are thought to be responsible for forming stratocumulus clouds over the Antarctic sea ice in spring and early summer.

The Antarctic sea ice covers an area of some 20 million square kilometres (the size of Russia) and contains the largest source of these chemicals on Earth.

As the Antarctic sea ice melts each year, these chemicals are released into the atmosphere where they form cloud condensation nuclei, which attract moisture to form clouds.

“The polar regions are presently changing faster than any other regions of the Earth,” Professor Jones said. “These changes are particularly evident in the widespread shrinking of snow and ice.

“Processes in polar regions have a profound impact on the global environment, and particularly on the weather and climate system of Australia.”

Dr Jones has received the funding to see how these cloud seeding chemicals vary with ice thickness because it is thought that as more and more sea ice melts from the effects of global warming, less of these cloud seeding chemicals will be emitted from the Antarctic sea ice resulting in more intense warming.

“Remote sensing techniques have been applied which show these chemicals are being emitted from the Antarctic sea ice in spring as the ice starts to melt,” Professor Jones said.

Two students from the School of Environmental Science and Management, Rebecca Kelley and Gargi Joshi, are currently on the Australian icebreaker, Aurora Australis, collecting sea ice cores from two north-south transects through the sea ice just off the Australian Antarctic research base of Casey in eastern Antarctica.

They are participating in the largest internationally coordinated research program in 50 years – the International Polar Year (IPY), which runs from 2007-2008. IPY research activities have come from the ideas of researchers from 60 countries and a total of 228 projects are currently underway in the Arctic and Antarctic.

Rebecca Kelley and Gargi Joshi are part of Australia’s contribution to IPY through their project ‘Antarctic Sea Ice in the International Polar Year’ being led by Dr Tony Worby of the Antarctic Climate and Ecosystems CRC and the Australian Antarctic Division.

“Their research involves a large multidisciplinary study of the physics, biology and chemistry of the Antarctic sea ice in spring,” Professor Jones said. “The data collected will provide valuable information for existing and future satellite missions and improve our understanding of the role of sea ice in the climate system.

“It is also hoped that this information will help us understand regional climate change in Australia.”

To help with education and outreach of this science program, high school students in Australia can access the web site to learn more about the experiment.

Photo: Australian icebreaker, Aurora Australis, currently home base for SCU research students Rebecca Kelley and Gargi Joshi, who are collecting sea ice core samples.