The amount of sea ice in the Arctic has increased by close to 50 per cent compared to last year, according to satellite measurements.
ESA’s CryoSat mission revealed that in October this year the Arctic had 9000 cu km of sea ice. This compares to just 6000 cu km in October 2012.
Scientists believe part of this stronger performance is due to a greater retention of older ice.
Over the last few decades, satellites have shown a downward trend in the area of Arctic Ocean covered by ice.
However, the actual volume of sea ice has proven difficult to find out because it moves around and so its thickness can change.
The CryoSat-2 satellite was designed to measure sea-ice thickness across the entire Arctic Ocean, and has allowed scientists, for the first time, to monitor the overall change in volume accurately.
Scientists claim around 90 per cent of the increase is due to growth of multi-year ice – which survives through more than one summer without melting – with only 10 per cent growth of first year ice.