A couple of days ago the NSIDC released its latest analysis for the month of September.
For the exact numbers with regards to the shattered record I refer you to the article itself. This graph says it all:
The analysis then moves on to some interesting comparisons with 2007. First off, the differences in atmospheric patterns, something I wrote about at the end of July (Arctic atmosphere June-July 2012):
Weather conditions prevailing over the summer of 2012 were quite different from those in 2007. The summer of 2007 featured unusually high sea level pressure centered north of the Beaufort Sea and Greenland, and unusually low pressure along northern Eurasia, bringing in warm southerly winds along the shores of the East Siberian and Chukchi seas (3 to 5 degrees Celsius, or 5 to 9 degrees Fahrenheit above normal), favoring strong ice melt in these sectors and pushing the ice away from the coast, leaving open water. The pressure pattern also favored the transport of ice out of the Arctic Ocean and into the North Atlantic through Fram Strait.
These images compare sea level pressure and temperature anomalies (at the 925 hPa level) during summer 2007, the previous record low extent year, and summer 2012. Anomalies were less pronounced in 2012 than in 2007 (as shown in reds and oranges). While weather was a factor in the 2007 record low extent, the 2012 record extent occurred during near average weather conditions. Credit: NSIDC courtesy NOAA/ESRL PSD
In contrast, the summer of 2012 saw unusually low pressure along the Eurasian coastal seas and extending eastward into the Beaufort sea, most prominently over the East Siberian Sea, with unusually high pressure centered over Greenland and the northern North Atlantic. Air temperatures for summer 2012 were above average over most of the Arctic Ocean (1 to 3 degrees Celsius, or 2 to 5 degrees Fahrenheit), most prominently over the Beaufort Sea, where, because of the pressure pattern, winds were anomalously from the south. Melt began two to three weeks earlier than average in the Barents and Kara seas, leading to earlier retreat of sea ice in the region; however, air temperatures remained below average during summer in this region. This points to the impact the continued loss of old, thick ice is having on the ability of the sea ice cover to survive summer melt. Other than the August storm, the pressure pattern in 2012 does not appear to have been as favorable in promoting ice loss as was the case in 2007, and yet a new record low occurred.
And then it's time for the yearly Arctic sea ice age map and graph:
The end-of-summer sea ice cover was not only the least extensive in the satellite record, but also very likely the lowest volume, based on combined model-observation estimates from the University of Washington, and inferred from ice age. The extent of ice of nearly all age categories declined from last year and remained at record low levels. The only category that increased was 4-year-old ice. This is ice that has aged since the previous record low minimum extent in 2007, when substantial amounts of first-year ice were lost. This 4-year-old ice will now age into the 5+ year category as the ice-growth season begins. However, even with this replenishment this winter will see only approximately 20% of the old (5+ year) ice compared to the 1980s. Because of the record summer ice loss, this winter will see the Arctic Ocean region even more dominated by the thinner first-year ice. As shown in Figure 5, the amount of ice in nearly all age categories has decreased since 2007, particularly the oldest ice.
The analysis ends with some background info on the Antarctic sea ice maximum. It's very nice of the NSIDC to provide the background information lacking in the yearly fake skeptic diversionary action, aimed at downplaying what's going on up North (anyone still falling for that?). This piece on the New York Times blog by Justin Gillis also puts things nicely into perspective: Running the numbers on Antarctic sea ice