Arctic sea ice reaches minimum 2011 extent, making it second lowest in satellite record

Sep 15, 2011
This chart shows the 2011 September minimum of Arctic sea ice extent compared with the median 1979-2000 September minimum measurements. Credit: NSIDC

The blanket of sea ice that floats on the Arctic Ocean appears to have reached its lowest extent for 2011, the second lowest recorded since satellites began measuring it in 1979, according to the University of Colorado Boulder's National Snow and Ice Data Center.

The extent fell to 1.67 million square miles, or 4.33 million square kilometers on Sept. 9, 2011. This year's minimum of 1.67 million square miles is more than 1 million square miles below the 1979-2000 monthly average extent for September -- an area larger than Texas and California combined.

While this year's September minimum extent was greater than the all-time low in 2007, it remains significantly below the long-term average and well outside the range of natural climate variability, according to scientists involved in the analysis. Most scientists believe the shrinking Arctic sea ice is tied to warming temperatures caused by an increase in human-produced pumped into Earth's atmosphere.

"Every summer that we see a very low ice extent in September sets us up for a similar situation the following year," said NSIDC Director Mark Serreze, also a professor in CU-Boulder's geography department. "The Arctic sea ice cover is so thin now compared to 30 years ago that it just can't take a hit anymore. This overall pattern of thinning ice in the Arctic in recent decades is really starting to catch up with us."

Serreze said that in 2007, the year of record low Arctic sea ice, there was a "nearly perfect" set-up of specific . Winds pushed in more warm air over the Arctic than usual, helping to melt sea ice, and winds also pushed the chunks together into a smaller area. "It is interesting that this year, the second lowest sea ice extent ever recorded, that we didn't see that kind of at all," he said.

The last five years have been the five lowest Arctic sea ice extents recorded since began in 1979, said CU-Boulder's Walt Meier, an NSIDC scientist. "The primary driver of these low sea ice conditions is rising temperatures in the Arctic, and we definitely are heading in the direction of ice-free summers," he said. "Our best estimates now indicate that may occur by about 2030 or 2040."

There still is a chance the could fall slightly due to changing winds or late season melt, said Meier. During the first week of October, CU-Boulder's NSIDC will issue a full analysis of the 2011 results and a comparison to previous years.

Explore further: NASA balloons begin flying in Antarctica for 2014 campaign

add to favorites email to friend print save as pdf

Related Stories

Winter Sea Ice Fails to Recover, Down to Record Low

Apr 06, 2006

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 ...

Recommended for you

Scientists make strides in tsunami warning since 2004

18 hours ago

The 2004 tsunami led to greater global cooperation and improved techniques for detecting waves that could reach faraway shores, even though scientists still cannot predict when an earthquake will strike.

Trade winds ventilate the tropical oceans

19 hours ago

Long-term observations indicate that the oxygen minimum zones in the tropical oceans have expanded in recent decades. The reason is still unknown. Now scientists at the GEOMAR Helmholtz Centre for Ocean Research ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

Vendicar_Decarian
4 / 5 (4) Sep 15, 2011
Nanobanano
4.2 / 5 (6) Sep 15, 2011
Wait till the volume data gets fully computed.

I'm pretty sure this year is going to be significantly lower than 2007's minimum sea ice volume, as it was already equal or lower than the minimum volume about 5 weeks ago, and yeah, the historical volume minimum is september 1, but I don't think they've finished doing the calculations yet...

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.