The analysis produced a summer Arctic sea-ice minimum extent of 6.9 million sq km.

BBC: Earliest satellite maps of Antarctic and Arctic sea-ice

Each year, the Arctic sea ice reaches its minimum extent in September.

UNESCO: EDUCATION

Climate change models of Arctic sea ice cover in September, the month when ice is usually at its minimum, suggest an average loss of 2.5 percent of ice cover per decade from 1953 to 2003.

CNN: Arctic melt worse than predictions