The graph above shows daily sea ice extent.The solid light blue line indicates 2008; the dashed green line shows 2007; the dotted line shows 2005; the solid gray line indicates average extent from 1979 to 2000. Sea Ice Index data. Credit: National Snow and Ice Data Center

The Arctic sea ice cover appears to have reached its minimum extent for the year, the second-lowest extent recorded since satellite record-keeping began in 1979, according to the University of Colorado at Boulder's National Snow and Ice Data Center, or NSIDC.

While slightly above the record-low minimum set on Sept. 16, 2007, this season further reinforces the strong negative trend in summertime sea ice extent observed over the past 30 years, according to NSIDC researchers.

NSIDC will issue a press release at the beginning of October with full analysis of the possible causes behind this year's low ice conditions, particularly interesting aspects of the melt season, the conditions going into the winter growth season ahead, and graphics comparing this year to the long-term record.

Source: University of Colorado at Boulder, NSIDC