A year-round satellite sea-ice thickness record from CryoSat-2.

Arctic sea ice is diminishing with climate warming at a rate unmatched for at least 1,000 years. As the receding ice pack raises commercial interest in the Arctic, it has become more variable and mobile, which increases safety risks to maritime users. Satellite observations of sea-ice thickness are currently unavailable during the crucial melt period from May to September, when they would be most valuable for applications such as seasonal forecasting, owing to major challenges in the processing of altimetry data.