Winter sea ice ties for lowest on record

The Arctic sea ice cover appeared to reach its largest extent for the 2010-11 winter on March 7, with that extent tying with the 2006 extent for the lowest on record since satellite observations began in 1979, the National Snow and Ice Data Center reported on March 23. At 5.65 million square miles, the maximum extent was 471,000 squares miles below the 1979 to 2000 average, NSIDC said.

However, although NSIDC thinks that March 7 probably marks this year’s maximum extent, there is a chance of the ice cover expanding again.

“The thin ice is highly sensitive to weather, moving or melting quickly in response to changing winds and temperatures, and it often oscillates near the maximum extent for several days or weeks, as it has done this year,” NSIDC said.

—Alan Bailey