GLOBAL: Arctic sea ice melting

Rising air temperatures in the Arctic region have led to an increase in rainfall and a decrease in snowfall, making the sea ice more susceptible to melting, a new study has revealed. The Arctic region is warming more rapidly than anywhere else on Earth, say the researchers.

Results of the research were presented this month at the International Union of Geodesy and Geophysics General Assembly in Melbourne.

Dr James Screen, from the University of Melbourne's school of earth sciences who led the research, said warming temperatures meant that on more days of the year, and in more parts of the polar region, temperatures were becoming too warm for protective snow to form.

"As a result of this temperature shift, we estimate that there has been a 40% decrease in summer snowfall over the last 20 years," Screen said. "The reductions in snowfall in the summer months when there is still typically significant snow in Arctic regions have knock-on effects for the sea ice - the ice floating on top of the Arctic Ocean."

He said snow was highly reflective and bounced up to 85% of the incoming sunlight back into space. Snow on top of ice effectively acted as a sunscreen protecting the ice from the power of the sun's rays.

"As the snow cover has decreased, more sea ice has become exposed to the sunlight, increasing the melting of the ice. Measurements show that the sea ice has been getting thinner and less extensive," Screen said

The study was conducted with Professor Ian Simmonds, also of the university's school of earth sciences. A report of the research was published in the international journal Climate Dynamics.