Winter Sea Ice Fails to Recover, Down to Record Low

Apr 06, 2006
Winter Sea Ice Fails to Recover, Down to Record Low
March 2006 mean sea ice extent, indicated by the red dot, is 300,000 square kilometers (115,860 square miles) less than the 2005 record, and 1.2 million square kilometers (463,000 square miles) below the 1979-2000 mean.

Scientists at NSIDC announced that March 2006 shows the lowest Arctic winter sea ice extent since the beginning of the satellite record in 1979 (see Figures 1 and 2). Sea ice extent, or the area of ocean that is covered by at least 15 percent ice, was 14.5 million square kilometers (5.60 million square miles) for this March, as compared to 14.8 million square kilometers (5.72 million square miles) for March 2005, the previous record.

The Arctic sea ice shrinks during the summer and grows, or recovers, during the winter. The ice reaches its maximum extent during March, with a long-term (1979-2000) monthly mean extent of 15.7 million square kilometers (6.06 million square miles). Winter sea ice extent has begun to show a significant downward trend over the past four years.

However, the winter recovery trend is not as striking as the sea ice minimum trend (see the press release Sea Ice Decline Intensifies, 28 September 2005). Changes in the sea ice minimum extent are especially important because more of the sun's energy reaches Earth's surface during the Arctic summer than during the Arctic winter. Sea ice reflects much of the sun's radiation back into space, whereas dark ice-free ocean water absorbs more of the sun's energy. So, reduced sea ice during the sunnier summer months has more of an impact on the Arctic's overall energy balance than reduced ice in the winter.

The lower winter extents are still important, however, because they reflect the pattern of reduced sea ice that scientists have already seen. Low winter recovery means that the ice is freezing up later in the fall and growing at a slower pace in the winter.

Walt Meier of NSIDC notes, "Poor winter recovery of the sea ice leads to less new ice growth and thinner ice. The weaker the ice at the end of winter, the more easily it melts the following summer."

Source: National Snow and Ice Data Center

Explore further: Europe postpones launch of first 'space plane'

add to favorites email to friend print save as pdf

Related Stories

Hacker gets prison for cyberattack stealing $9.4M

1 hour ago

An Estonian man who pleaded guilty to orchestrating a 2008 cyberattack on a credit card processing company that enabled hackers to steal $9.4 million has been sentenced to 11 years in prison by a federal judge in Atlanta.

Remains of French ship being reassembled in Texas

2 hours ago

A frigate carrying French colonists to the New World that sank in a storm off the Texas coast more than 300 years ago is being reassembled into a display that archeologists hope will let people walk over ...

Icelandic volcano sits on massive magma hot spot

2 hours ago

Spectacular eruptions at Bárðarbunga volcano in central Iceland have been spewing lava continuously since Aug. 31. Massive amounts of erupting lava are connected to the destruction of supercontinents and ...

Magic Leap moves beyond older lines of VR

2 hours ago

Two messages from Magic Leap: Most of us know that a world with dragons and unicorns, elves and fairies is just a better world. The other message: Technology can be mindboggingly awesome. When the two ...

NBCUniversal settles with unpaid interns for $6.4M

3 hours ago

NBCUniversal will pay $6.4 million to settle a class action lawsuit brought by unpaid interns who worked on "Saturday Night Live" and other shows who claim they are owed wages, according to court documents.

Recommended for you

Hinode satellite captures X-ray footage of solar eclipse

4 hours ago

The moon passed between the Earth and the sun on Thursday, Oct. 23. While avid stargazers in North America looked up to watch the spectacle, the best vantage point was several hundred miles above the North ...

Asteroid 2014 SC324 zips by Earth Friday afternoon

14 hours ago

What a roller coaster week it's been. If partial eclipses and giant sunspots aren't your thing, how about a close flyby of an Earth-approaching asteroid?  2014 SC324 was discovered on September 30 this ...

User comments : 0