Geophys. Res. Lett. http://doi.org/r8k (2014)

Predictions of the September Arctic sea-ice extent (summer minimum) are made at the start of every summer. Since 2008 they have been collected by the Study of Environmental Arctic Change (SEARCH) to form the Sea Ice Outlook. There are a number of techniques used to create these projections, including modelling and statistical methods.

Julienne Stroeve, of the National Snow and Ice Data Centre, Boulder, Colorado, USA and co-workers investigated the skill of the collected predictions for the six years of available data. Comparing the ensemble of predictions with the September mean extent shows that for years when sea-ice extent is in agreement with the overall decreasing trend, the median predictions are accurate. Whereas for anomalous years the prediction skill is poor. The authors note that the error value is only a slight improvement on a series of linear predictions based on the historical trend. This work highlights that predicting year-to-year variations in of Arctic sea-ice extent remains a challenge.