Scientists at the University of Bremen are saying Arctic sea ice extent reached a new record low this year.
Alerting message from the Arctic: The extent the Arctic sea ice has reached on Sep. 8 with 4.240 million km2 a new historic minimum (Figure 1). Physicists of the University of Bremen now confirm the apprehension existing since July 2011 that the ice melt in the Arctic could further proceed and even exceed the previous historic minimum of 2007. It seems to be clear that this is a further consequence of the man-made global warming with global consequences. Directly, the livehood of small animals, algae, fishes and mammals like polar bears and seals is more and more reduced.

- Sea ice extent of the years 2003 to 2011 with minima in September and maxima in March.
The University of Bremen’s ice map shows the Northwest and Northeast passages are simultaneously ice free
This happened for the first time in 2008 – it did not happen in 2007, the year that saw the record minimum ice extent.

- Sea ice concentration maps of the minimum 2007 and of the first day of historic minimum in 2011. The 2011 sea ice area could reduce further in the next days.
The daily sea ice maps of the University of Bremen are based on observations of the Japanese microwave sensor AMSR-E, in orbit on board the NASA spacecraft Aqua since 2002. The institute receives the data from two servers in the US and Japan and produces the maps based on the ASI (ARTIST Sea Ice) algorithm using the 89 GHz channels of AMSR-E. Other retrieval algorithms like NASA Team or Bootstrap may find slightly different sea ice extent values.
To wit: the National Snow and Ice Data Center has just called the yearly minimum Arctic sea ice extent, finding it the second lowest in the satellite record.
Arctic sea ice appears to have reached its lowest extent for the year. The minimum ice extent was the second lowest in the satellite record, after 2007, and continues the decadal trend of rapidly decreasing summer sea ice.
Please note that this is a preliminary announcement. Changing winds could still push ice flows together, reducing ice extent further. NSIDC scientists will release a full analysis of the melt season in early October, once monthly data are available for September.
* * *
The last five years (2007 to 2011) have been the five lowest extents in the continuous satellite record, which extends back to 1979. While the record low year of 2007 was marked by a combination of weather conditions that favored ice loss (including clearer skies, favorable wind patterns, and warm temperatures), this year has shown more typical weather patterns but continued warmth over the Arctic. This supports the idea that the Arctic sea ice cover is continuing to thin. Models and remote sensing data also indicate this is the case. A large area of low concentration ice in the East Siberian Sea, visible in NASA Moderate Resolution Imaging Spectroradiometer (MODIS) imagery, suggests that the ice cover this year is particularly thin and dispersed this year.
The Japan Aerospace Exploration Agency (JAXA) also pegs 2011 as the second lowest year for Arctic sea ice extent.

If September 9 holds up as the date of minimum ice extent, that’s the earliest date of minimum extent in years – and earlier than the average date (September 10) over the period of satellite records, which began in 1979.
While the absolute sea ice extent values might vary slightly from one method to the other – and even the day of the absolute minimum might vary slightly – all methods find consistently that all minima since 2007 have been lower than all minima before, i.e. the last four minima (2007-2011) are the four lowest on record.
And there’s little doubt that 2011 saw new record for Arctic sea ice volume . . .

. . . and area.

Global warming and climate change have already come to the Arctic. The full consequences of this new reality have yet to be seen.