Measurements from Europe’s CryoSat spacecraft reveal that about 2,160 cubic miles of sea ice covered the Arctic in late October.
That’s up from the 1,440 cubic miles that CryoSat measured during the record low for the ice in 2012.
Scientists say that about 90 percent of the increase is due to growth of multiyear ice, which is thick enough to last through more than one summer without melting.
“Although the recovery of Arctic sea ice is certainly welcome news, it has to be considered against the backdrop of changes that have occurred over the last few decades,” said Andy Shepherd of University College London.
He told the BBC that there were about 4,800 cubic miles of Arctic sea ice each October during the early 1980s, decades before a rapid warming of the polar region brought unprecedented melting.
Graphic: European Space Agency