The Arctic Sea Ice Is Melting Rapidly

- The 2005 spring and summer melting began about 17 days earlier than usual

By: Tudor Raiciu,
Technology and Science Editor
Sept. 28, 2005

New satellite records monitored by a national team of collaborators show a four-year pattern of extremely low summer sea-ice coverage in the Arctic that continued in September 2005, which may be the result of warming temperatures and earlier spring melting.

Since 2002, the satellite data have revealed unusually early springtime melting in areas north of Siberia and Alaska. In 2005, the trend expanded to include the entire Arctic ice pack, said Ted Scambos of CU-Boulder's National Snow and Ice Data Center, which led the study that also involved NASA and the University of Washington.

The research group used the satellite record, dating back to 1978, to determine that the 2005 spring and summer melting began about 17 days earlier than usual, a new record. Average air temperatures across most of the Arctic Ocean from January to August 2005 were between 3.6 degrees F and 5.4 degrees F warmer than average compared to the last 50 years, said the team.

The conditions were followed by the lowest sea-ice extent yet seen in the satellite data, a five-day mean average of 2.06 million square miles on Sept. 19. The team reported the extent was lower than the mean average September sea-ice extent from 1978 to 2001 by about 20 percent, or 500,000 square miles, an area about twice the size of Texas.

"Since the 1990s, The melting and retreat trends are accelerating," said Scambos. "And the one common thread is that Arctic temperatures over the ice, ocean and surrounding land have increased in recent decades."

The winter of 2004-2005 exhibited the smallest recovery of Arctic sea ice of any previous winter in the 23-year satellite record, the group reported. With the exception of May 2005, every month since November 2004 has exhibited the lowest monthly average of sea-ice extent since satellite record-keeping began in the region.