Arctic sea-ice ponding may predict summer melt extent

BBC : Through the 1990s, the area covered by Arctic sea ice never dropped below 7 million km² during the summer. Over the past five years, however, it has averaged just 5 million km², with a minimum of 3.6 million km² in 2012. Because the year-by-year variation is large, no computer models have succeeded in predicting the extent of the yearly melting. Now Daniel Feltham of Reading University in the UK and his colleagues believe they’ve found a strong correlation between the area of ponds that form on ice floes in May and the amount of ice melted at the summer minimum ice cover in September. They created their model based on satellite data that revealed the darker water of the ice ponds. Using current satellite data from May, Feltham and colleagues have predicted that Arctic sea ice will reach a minimum coverage of about 5.4 million km² in September. If their model is accurate, it could be useful for trans-Arctic shipping and improving overall climate models.