The National Snow & Ice Data Center has declared that the Arctic Sea ice extent has reached its annual minimum and is now starting to expand. I was thinking that it was too early to say this, since in past years what looks like a minimum can sometimes be reversed by some additional melting. But they are the experts, so I suppose we should go with it for now.
If this is the case, then this is the fourth lowest minimum in the good data set covering the last several decades.
They do hedge a bit. Here is what they say:
On September 11, Arctic sea ice reached its likely minimum extent for 2015. The minimum ice extent was the fourth lowest in the satellite record, and reinforces the long-term downward trend in Arctic ice extent. Sea ice extent will now begin its seasonal increase through autumn and winter. In the Antarctic, sea ice extent is average, a substantial contrast with recent years when Antarctic winter extents reached record high levels.
Please note that this is a preliminary announcement. Changing winds or late-season melt could still reduce the Arctic ice extent, as happened in 2005 and 2010. NSIDC scientists will release a full analysis of the Arctic melt season, and discuss the Antarctic winter sea ice growth, in early October.