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Title: Early sea ice melt onset, snow cover retreat presage rapid 2011 summer decline
Source:
nsidc
URL Source: http://nsidc.org/arcticseaicenews/2011/071811.html
Published: Jul 19, 2011
Author: nsidc
Post Date: 2011-07-19 23:40:56 by go65
Keywords: None
Views: 4919
Comments: 13
Arctic sea ice extent declined at a rapid pace through the first half of July, and is now tracking below the year 2007, which saw the record minimum September extent. The rapid decline in the past few weeks is related to persistent above-average temperatures and an early start to melt. Snow cover over Northern Eurasia was especially low in May and June, continuing the pattern seen in April. Overview of conditions As of July 17, 2011, Arctic sea ice extent was 7.56 million square kilometers (2.92 million square miles), 2.24 million square kilometers (865,000 square miles) below the 1979 to 2000 average. Sea ice is particularly low in the Barents, Kara, and Laptev Seas (the far northern Atlantic region), Hudson Bay and Baffin Bay. Figure 2. The graph above shows daily Arctic sea ice extent as of July 17, 2011, along with daily ice extents for previous low-ice-extent years. Light blue indicates 2011, dashed green shows 2007, dark blue shows 2010, and dark gray shows the 1979 to 2000 average. The gray area around the average line shows the two standard deviation range of the data. Sea Ice Index data. —Credit: National Snow and Ice Data Center Arctic sea ice extent declined rapidly through the first two weeks of July, at a rate averaging nearly 120,000 square kilometers (46,000 square miles) per day. Ice extent is now tracking below the year 2007, which saw the record minimum September extent. During the first half of July, a high-pressure cell persisted over the northern Beaufort Sea, as it did in June, and is linked to the above-average air temperatures over much of the Arctic Ocean. To date in July, air temperatures over the North Pole (at the 925 millibar level, or roughly 1,000 meters or 3,000 feet above the surface) were 6 to 8 degrees Celsius (11 to 14 degrees Fahrenheit) higher than normal, while temperatures along the coasts of the Laptev and East Siberian seas were 3 to 5 degrees Celsius (5 to 9 degrees Fahrenheit) higher than average. By contrast, temperatures through the first half of July over the Kara Sea have been 2 to 5 degrees Celsius (4 to 9 degrees Fahrenheit) lower than average. 
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#1. To: All (#0)
NOAA just reported they expect a heat index of 116-118 between Richmond VA and Washington D.C. by Friday.
Tagline for sale - inquire within
The right wing conspiracists say climate change is a big hoax.
Not where I am. It is another very cool summer here.
Summer follows Spring, Film at 11.
Nothing will be done. Except to grow til we die. No different than yeast. We're only wondering what will replace us now.... Insect or Plant or Animal? 8D
Have YOU driven a Prius Today?
Arctic sea ice extent declined at a rapid pace through the first half of July, and is now tracking below the year 2007, which saw the record minimum September extent. The rapid decline in the past few weeks is related to persistent above-average temperatures and an early start to melt. In fact, “air temperatures over the North Pole were 6 to 8 degrees Celsius (11 to 14 degrees Fahrenheit) higher than normal.”
Antarctic ice is growing, not melting away Ice expanding in much of Antarctica Eastern coast getting colder Western section remains a concern ICE is expanding in much of Antarctica, contrary to the widespread public belief that global warming is melting the continental ice cap. The results of ice-core drilling and sea ice monitoring indicate there is no large-scale melting of ice over most of Antarctica, although experts are concerned at ice losses on the continent's western coast. Antarctica has 90 per cent of the Earth's ice and 80 per cent of its fresh water, The Australian reports. Extensive melting of Antarctic ice sheets would be required to raise sea levels substantially, and ice is melting in parts of west Antarctica. The destabilisation of the Wilkins ice shelf generated international headlines this month. However, the picture is very different in east Antarctica, which includes the territory claimed by Australia. East Antarctica is four times the size of west Antarctica and parts of it are cooling. The Scientific Committee on Antarctic Research report prepared for last week's meeting of Antarctic Treaty nations in Washington noted the South Pole had shown "significant cooling in recent decades". Australian Antarctic Division glaciology program head Ian Allison said sea ice losses in west Antarctica over the past 30 years had been more than offset by increases in the Ross Sea region, just one sector of east Antarctica. "Sea ice conditions have remained stable in Antarctica generally," Dr Allison said. The melting of sea ice - fast ice and pack ice - does not cause sea levels to rise because the ice is in the water. Sea levels may rise with losses from freshwater ice sheets on the polar caps. In Antarctica, these losses are in the form of icebergs calved from ice shelves formed by glacial movements on the mainland. Last week, federal Environment Minister Peter Garrett said experts predicted sea level rises of up to 6m from Antarctic melting by 2100, but the worst case scenario foreshadowed by the SCAR report was a 1.25m rise. Mr Garrett insisted global warming was causing ice losses throughout Antarctica. "I don't think there's any doubt it is contributing to what we've seen both on the Wilkins shelf and more generally in Antarctica," he said. Dr Allison said there was not any evidence of significant change in the mass of ice shelves in east Antarctica nor any indication that its ice cap was melting. "The only significant calvings in Antarctica have been in the west," he said. And he cautioned that calvings of the magnitude seen recently in west Antarctica might not be unusual. "Ice shelves in general have episodic carvings and there can be large icebergs breaking off - I'm talking 100km or 200km long - every 10 or 20 or 50 years." Ice core drilling in the fast ice off Australia's Davis Station in East Antarctica by the Antarctic Climate and Ecosystems Co-Operative Research Centre shows that last year, the ice had a maximum thickness of 1.89m, its densest in 10 years. The average thickness of the ice at Davis since the 1950s is 1.67m. A paper to be published soon by the British Antarctic Survey in the journal Geophysical Research Letters is expected to confirm that over the past 30 years, the area of sea ice around the continent has expanded.
Why Antarctic Sea Ice Is Growing in a Warmer World Models solve mystery, but suggest South Pole sea ice melt will soon accelerate. National Geographic News Published August 16, 2010 Climate scientists have cracked the mystery of why Antarctic sea ice has managed to grow despite global warming—but the results suggest the trend may rapidly reverse, a new study says. Satellite data show that, over the past 30 years, Arctic sea ice has declined while Antarctic sea ice has mysteriously expanded, according to study leader Jiping Liu, a research scientist at Georgia Tech in Atlanta. "We've seen this paradox, but we don't know why—here we gave an explanation," Liu said. The new analyses are based on climate models and sea-surface temperature and precipitation observations from 1950 to 2009. They show that, in the 20th century, ocean warming boosted precipitation in the upper atmosphere over the Antarctic region, which fell as snow. More snow made the top layers of the ocean less salty and thus less dense. These layers became more stable, preventing warm, density-driven currents in the deep ocean from rising and melting sea ice. (Test your ocean IQ.) Global Warming to Speed Up Antarctic Melting? The data show that Antarctic sea ice growth in the 20th century might be mostly dictated by natural processes, Liu noted. But that won't be the case for the 21st century, since human-caused global warming is predicted to dominate the Antarctic climate and trigger faster melting of sea ice, he said. (See a map of global warming impacts worldwide.) As increasing greenhouse gases continue to warm the oceans off Antarctica, more Antarctic precipitation will turn to rain, which rapidly melts snow and ice, according to the study, published this week in the journal Proceedings of the National Academy of Sciences. The more the ice melts, the more the sun's rays are absorbed into the dark ocean instead of being reflected back into the atmosphere, according to the study. This will further warm the ocean and melt even more sea ice. The scientists predict the transition from natural variability to greenhouse-gas warming will begin soon: "I cannot give you a precise year—but definitely in this century," Liu said. (See a greenhouse effect interactive.) The oceans off Antarctica are the world's most biologically productive, and declining sea ice could have a "substantial impact on the Antarctic marine ecosystem," Liu said. For instance, many Antarctic species rely on sea ice for hunting and overall survival. Antarctic penguins—many of which may disappear if warming continues—are among the animals at risk, conservationists say. A loss of sea ice could also throw a wrench in how ocean water travels around the world, Liu noted: The oceans off Antarctica include Earth's coldest, densest water, which is one of the "dominant driving forces" for the ocean's global conveyor belt, a circulation pattern that provides nutrients for up to three-quarters of marine life. Ozone Hole Missing in Sea Ice Study The study results aren't surprising, since they're in line with previous predictions that Antarctic sea-ice loss would accelerate, said Walt Meier of the National Snow and Ice Data Center (NSIDC) in Boulder, Colorado. "That's been the conventional wisdom—this is a modeling study [that] does actual physics that confirms" this idea, Meier said. The paper also helps to dispel a common misconception—that the strong decline in Arctic ice and increase in Antarctic ice causes a net zero effect, Meier said. That's not the case, because the two polar ecosystems are so different, he said. Arctic ice is multiyear, persisting through the seasons, while Antarctic ice forms and melts each year and has always been governed more by wind and ocean circulation than air temperatures, he said. That's not to say the melting effects of temperature, as seen in the Arctic, won't also occur in the Antarctic—they'll just take longer to show up, he said. But Kevin Trenberth, a senior scientist at the Boulder, Colorado-based National Center for Atmospheric Research, said that the paper has a major omission: the influence of the hole in the ozone layer. Bright summertime clouds spurred by the hole have acted as shields against global warming, scientists say. Recent research suggests the hole may finally be closing, following the phase-out of ozone-depleting chemicals called chlorofluorocarbons. And as the sun-reflecting clouds dissipate, temperatures in the Southern Hemisphere may rise faster than currently predicted by models. The ozone hole has been a reason "why Antarctica has not warmed the same way as other parts of the world," Trenberth said by email. "How the ozone hole recovery comes about in the future is a major factor in expected developments, as shown in some model simulations—but these aspects are not dealt with in this paper." Study author Liu agrees that the ozone hole influences sea ice, but "I am not sure if ozone depletion really play[s] a significant role in the Antarctic sea ice variability."
The same crap every year and nobody is listening to this chicken little bullshit any more.
Now, I know I’m not going to change the minds of any of the True Believers…those who read all of Reverend Al’s sermons, and say things like, “You know, global warming can mean warmer OR colder, wetter OR drier, cloudier OR sunnier, windier OR calmer, …”. Can I get an ‘amen’??
Do you not realize that's from 2009? Just a few weeks ago scientists reported that ice at Antarctica's biggest western glacier is melting 50% faster than in 1994. http://www.bloomberg.com/news/2011-06-26/antarctica-s-pine-glacier-melting-50-faster-study- indicates.html
Tagline for sale - inquire within
But way different than a yeast infection. See yukon.
No, thanx. I'll take your word for it...;}
#2. To: go65 (#0)
rapid 2011 summer decline
#3. To: go65 (#0)
Early sea ice melt onset,
#4. To: go65 (#0)
#5. To: socalv8 (#4)
#6. To: NewsJunky (#2)
The right wing conspiracists say climate change is a big hoax.
#7. To: Get Outta Dodge! (#6)
#8. To: go65 (#0)
To preserve our independence, we must not let our rulers load us with perpetual debt. We must make our election between economy and liberty, or profusion and servitude. — Thomas Jefferson
#9. To: jwpegler (#8)
#10. To: go65 (#0)
#11. To: jwpegler (#8)
Antarctic ice is growing, not melting away
#12. To: mcgowanjm (#5)
No different than yeast.
#13. To: socalv8 (#12)
But way different than a yeast infection. See yukon.
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