Geophys. Res. Lett. http://doi.org/hqx (2012)

Arctic sea ice has been decreasing for the past 30 years. Model simulations of sea-ice extent have a tendency to underestimate this decline, with cloud feedback being a large source of uncertainty. Improved knowledge of the role of clouds in Arctic climate is needed to improve predictions of sea-ice cover in coming years.

Clouds are known to influence sea-ice growth and melt. To improve quantification of this relationship, Yinghui Liu, of the University of Wisconsin in Madison, and colleagues studied satellite data from 2000–2010, to measure sea-ice coverage and cloud amount.

Results show that for each 1% decrease in sea ice there is around a 0.4–0.5% increase in cloud cover during the July–November period. Increased cloud amount constitutes a positive climate feedback by trapping longwave radiation, which leads to greater warming and further accentuates sea-ice melt. 22–34% of cloud variability is linked to variability of sea ice. These findings indicate that further warming and sea-ice melt in coming years could lead to cloudier skies in the Arctic.