Annals of Global Warming: Arctic ice at second lowest level ever measured

October 12, 2011

Two years ago warming denialists claimed the Earth is actually cooling, and they predicted dramatic cooling by late 2010.

Instead, warming continues, overcoming the temporary mediation caused by increased particulate and sulfate emissions from coal burned in uncontrolled fashion in China, as evidence by things like the continued shrinking of Arctic ice below 20th century averages.  See this press release from NASA:

RELEASE : 11-337 – October 4, 2011

 Arctic Sea Ice Continues Decline, Hits Second-Lowest Level

WASHINGTON — Last month the extent of sea ice covering the Arctic Ocean declined to the second-lowest extent on record. Satellite data from NASA and the NASA-supported National Snow and Ice Data Center (NSIDC) at the University of Colorado in Boulder showed that the summertime sea ice cover narrowly avoided a new record low.

The Arctic ice cap grows each winter as the sun sets for several months and shrinks each summer as the sun rises higher in the northern sky. Each year the Arctic sea ice reaches its annual minimum extent in September. It hit a record low in 2007.

The near-record ice-melt followed higher-than-average summer temperatures, but without the unusual weather conditions that contributed to the extreme melt of 2007. “Atmospheric and oceanic conditions were not as conducive to ice loss this year, but the melt still neared 2007 levels,” said NSIDC scientist Walt Meier. “This probably reflects loss of multiyear ice in the Beaufort and Chukchi seas as well as other factors that are making the ice more vulnerable.”

Joey Comiso, senior scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md., said the continued low minimum sea ice levels fits into the large-scale decline pattern that scientists have watched unfold over the past three decades.

“The sea ice is not only declining, the pace of the decline is becoming more drastic,” Comiso said. “The older, thicker ice is declining faster than the rest, making for a more vulnerable perennial ice cover.”

While the sea ice extent did not dip below the 2007 record, the sea ice area as measured by the microwave radiometer on NASA’s Aqua satellite did drop slightly lower than 2007 levels for about 10 days in early September, Comiso said. Sea ice “area” differs from extent in that it equals the actual surface area covered by ice, while extent includes any area where ice covers at least 15 percent of the ocean.

Arctic sea ice extent on Sept. 9, the lowest point this year, was 4.33 million square kilometers (1.67 million square miles). Averaged over the month of September, ice extent was 4.61 million square kilometers (1.78 million square miles). This places 2011 as the second lowest ice extent both for the daily minimum extent and the monthly average. Ice extent was 2.43 million square kilometers (938,000 square miles) below the 1979 to 2000 average.

This summer’s low ice extent continued the downward trend seen over the last 30 years, which scientists attribute largely to warming temperatures caused by climate change. Data show that Arctic sea ice has been declining both in extent and thickness. Since 1979, September Arctic sea ice extent has declined by 12 percent per decade.

“The oldest and thickest ice in the Arctic continues to decline, especially in the Beaufort Sea and the Canada Basin,” NSIDC scientist Julienne Stroeve said. “This appears to be an important driver for the low sea ice conditions over the past few summers.”

Climate models have suggested that the Arctic could lose almost all of its summer ice cover by 2100, but in recent years, ice extent has declined faster than the models predicted.

NASA monitors and studies changing sea ice conditions in both the Arctic and Antarctic with a variety of spaceborne and airborne research capabilities. This month NASA resumes Operation IceBridge, a multi-year series of flights over sea ice and ice sheets at both poles. This fall’s campaign will be based out of Punta Arenas, Chile, and make flights over Antarctica.  NASA also continues work toward launching ICESat-2 in 2016, which will continue its predecessor’s crucial laser altimetry observations of ice cover from space.

To see a NASA data visualization of the 2011 Arctic sea ice minimum as measured by the Advanced Microwave Scanning Radiometer – Earth Observing System (AMSR-E) on Aqua, visit:

http://www.nasa.gov/topics/earth/features/2011-ice-min.html  [I have changed the link to one that works for me.]

Here is that visualization, presented by Cryosphere Program Manager, Tom Wagner:

On Sept. 9th, 2011, Arctic sea ice most likely hit its minimum extent for the year. On Sept. 20th, NASA’s Cryosphere Program Manager, Tom Wagner, shared his perspectives on the ice with television audiences across the country.

On the top of the world, a pulsing, shifting body of ice has profound effects on the weather and climate of the rest of the planet. Every winter as temperatures dip, sea ice freezes out of cold Arctic Ocean waters, and every summer the extent of that ice shrinks as warm ocean temperatures eat it away. Ice cover throughout the year can affect polar ecosystems, world-wide ocean currents, and even the heat budget of the Earth.

During the last 30 years we’ve been monitoring the ice with satellites, there has been a consistent downward trend, with less and less ice making it through the summer. The thickness of that ice has also diminished. In 2011 Arctic sea ice extent was its second smallest on record, opening up the fabled Northwest Passages and setting the stage for more years like this in the future. In this video, NASA’s Cryosphere Program Manager, Tom Wagner, shares his perspectives on the 2011 sea ice minimum.

More data and animation versions here, at Goddard Multimedia.

 


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