Quantitative analysis has evidenced the acceleration system of melting ice: dark water surfaces absorb more heat than white ice surfaces, thus melting ice and making more water surfaces in the Arctic Ocean.
Quantitative analysis has evidenced the acceleration system of melting ice: dark water surfaces absorb more heat than white ice surfaces, thus melting ice and making more water surfaces in the Arctic Ocean.
Ice-covered sea areas in the Arctic Ocean during summer have nearly halved since the 1970s and 1980s, raising alarm that the ocean is shifting from a multiyear to a seasonal ice zone. The Intergovernmental Panel on Climate Change (IPCC) has forecasted summer ice cover in the polar ocean might disappear almost completely as early as 2050. Various factors have been cited as causes, including rising temperatures and changes in atmospheric circulation patterns.
Recently, however, ice-ocean “albedo feedback” has emerged as a key cause for sea ice melt. The feedback is generated by a large difference in albedo – a measure of light reflectivity – between open water and ice surfaces. As dark ocean surfaces absorb more light than white ice surfaces, solar heat input through the open water melts sea ice, increasing both open water areas and heat input and thus accelerating sea ice melt.
To examine this theory, a team of researchers including Hokkaido University Professor Kay I. Ohshima and Haruhiko Kashiwase of the National Institute of Polar Research, conducted a quantitative analysis of key factors such as solar energy input, ice melt volume and ice divergence of a sea area that has shown major ice melt.
Read more at Hokkaido University
Image: Walruses huddling together on a block of ice in the Arctic Ocean in August 2012 right before the summer ice cover hit a record low in the following month. (Credit: Photo taken by Toru Takatsuka, Institute of Low Temperature Science, Hokkaido University.)
