NASA has circulated some amazing photos of the Arctic sea ice coverage that show its lowest extent for the year, and the second-lowest amount recorded since the dawn of the satellite era, according to observations from the NASA-supported National Snow and Ice Data Center at the University of Colorado in Boulder.

The Advanced Microwave Scanning Radiometer (AMSR-E) is a high-resolution passive microwave Instrument on NASA’s Aqua satellite that provides a clear view of sea ice dynamics in greater detail than has ever been viewed before. Researchers use this information to study polar bear habitats, plan expeditions to the ice, and to study the interactions between the ocean and sea ice from season to season. This data visualization shows Arctic sea ice from July 1 to September 10, 2008, which is slightly above the record-low minimum set September 16, 2007, a negative trend in summer sea ice extent observed during the past 30 years. Prior to last year the record low for September was 2005. NASA scientists have been observing Arctic sea ice cover since 1979, and developed the capability to observe the extent and concentration of sea ice from space using passive microwave sensors.

In March, when the Arctic reached its annual maximum sea ice coverage during the winter, scientists from NASA and the data center reported that thick, older sea ice was continuing to decline. According to NASA-processed satellite microwave data, this perennial ice used to cover 50-60 percent of the Arctic, but this winter it covered less than 30 percent. Perennial sea ice is the long-lived layer of ice that remains even when the surrounding short-lived seasonal sea ice melts to its minimum extent during the summer.

The National Snow and Ice Data Center will issue an analysis of the possible causes behind this year's Arctic sea ice conditions during the first week of October. For updates, visit this website.