Researchers say the growth continued in 2014 and more than compensated for losses recorded in the three previous years.
The scientists involved believe changes in summer temperatures have greater impacts on ice than thought.
"We looked at various climate forcing factors, we looked at the snow loading, we looked at wind convergence and the melt season length of the previous summer," lead author Rachel Tilling, from University College London, told BBC News.
"We found that the the highest correlation by far was with the melt season length - and over the summer of 2013, it was the coolest of the five years we have seen, and we believe that's why there was more multi-year ice left at the end of summer."However, 2014 was supposed to have been the warmest on record (according to recently "adjusted" "data"). How can the warmest summer on record be reconciled with increased sea ice if that should have caused decreased sea ice?
Article: Arctic ice EMBIGGENS, returns to 1980s levels of cap cover
To be fair, it is total sea ice, Arctic and Antarctic, that has reached 1980's levels. While the Arctic ice is still down from its 1980's high, Antarctic ice is at record breaking levels, and still increasing.
Article: CCGS Amundsen re-routed to Hudson Bay to help with heavy ice
The Amundsen is an icebreaker. During the summer it does double-duty as a "floating research center."
Johnny Leclair, assistant commissioner for the Coast Guard, said Tuesday conditions in the area are the worst he's seen in 20 years.Because of the large amount of ice this summer (supposedly the hottest on record, so far) the icebreaker has had to return to its normal duties.
Trip down memory lane:
2007 Article, also at the BBC: Arctic summers ice-free 'by 2013'
Using supercomputers to crunch through possible future outcomes has become a standard part of climate science in recent years.
"We use a high-resolution regional model for the Arctic Ocean and sea ice forced with realistic atmospheric data. This way, we get much more realistic forcing..."Yes, the BBC actually used the section heading, "Real World."
Yet another falsification of the catastrophic anthropogenic global warming hypothesis.