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tagged w/ sea ice extent
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Arctic continues to warm rapidly as researchers fear tipping points
Last year the Arctic, which is warming faster than anywhere else on Earth due to global climate change, experienced its warmest twelve months yet. According to recent data by NASA, average Arctic temperatures in 2011 were 2.28 degrees Celsius (4.1 degrees Fahrenheit) above those recorded from 1951-1980. As the Arctic warms, imperiling its biodiversity and indigenous people, researchers are increasingly concerned that the region will hit climatic tipping points that could severely impact the rest of the world. A recent commentary in Nature Climate Change highlighted a number of tipping points that keep scientists awake at night.
"If set in motion, [tipping points] can generate profound climate change which places the Arctic not at the periphery but at the core of the Earth system," Professor Duarte, a climatologist with the University of Western Australia's Ocean Institute and co-author other paper, said in a press release. "There is evidence that these forces are starting to be set in motion. This has major consequences for the future of human kind as climate change progresses."
One of the tipping points is sea ice loss. The Arctic wasn't just relatively hot last year—beating the previous record set in 2010 by 0.17 degrees Celsius (0.3 degrees Fahrenheit)—it also experienced the lowest sea ice volume yet recorded, and the second-lowest extent. Sea ice is essential to many Arctic species, from polar bears to walrus, and narwhals to seals. In just over 30 years, sea ice volume has dropped precipitously, declining by 76 percent from 1979 (16,855 cubic kilometers) to 2011 (4,017 cubic kilometers). This loss of sea ice also leads to greater regional and global warming, as the Arctic's sea reflects the sun's light back into space, cooling not only the region but the world.
Sea ice loss may also be having a direct impact on weather in the mid-latitudes. In fact, recent research has suggested that, perhaps unintuitively, the extreme cold spell experienced by Europe this winter was linked to the sea ice decline in the Arctic. Researchers argue that the Arctic Oscillation, which is partially responsible for weather conditions in the Northern Hemisphere in winter, has become unhinged by the sea ice decline, causing more extreme winters, such as Europe's cold spell and the massive blizzards that hit the U.S. in 2009 and 2010.
But it's not just sea ice loss that has produced stark concerns: greenhouse gases from thawing permafrost could be just as disastrous. A study published in Nature late last year warned that greenhouse gas emissions due to permafrost thaw could equal the amount currently emitted by deforestation worldwide, a significantly larger estimate than has been put forward before. Moreover, since permafrost thaw emissions include methane, a more potent greenhouse gas than carbon, it could have an impact 2.5 times larger than deforestation overall.
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Further tipping points include an input of freshwater into the Atlantic Ocean from melting ice and glaciers, already increased by 30 percent, which Durate says "may affect the whole ocean current system and, as a result, the climate at a regional level."
Governments have responded to warming in the Arctic with a resource race. Governments with Arctic territories plan to drastically expand oil and gas exploitation, utilize new shipping routes, and increase mining. The industrialization of the Arctic, according to Duarte, may only accelerate impacts on the fragile region and push tipping points.
"[Arctic tipping points] represents a test of our capacity as scientists, and as societies to respond to abrupt climate change," Duarte said. "We need to stop debating the existence of tipping points in the Arctic and start managing the reality of dangerous climate change. We argue that tipping points do not have to be points of no return. Several tipping points, such as the loss of summer sea ice, may be reversible in principle—although hard in practice. However, should these changes involve extinction of key species—such as polar bears, walruses, ice-dependent seals and more than 1,000 species of ice algae—the changes could represent a point of no return."
The solution, Durate says, is to cut the fossil fuel emissions that are causing climate change.
CITATIONS: Carlos M. Duarte, Timothy M. Lenton, Peter Wadhams, Paul Wassmann. Abrupt climate change in the Arctic. Nature Climate Change, 2012; 2 (2): 60 DOI: 10.1038/nclimate1386.
Schuur, Edward A. G.; Abbott, Benjamin. Climate change: High risk of permafrost thaw. Nature. 480, 32–33. 2011. doi:10.1038/480032a.
Polar bears approach a U.S. attack sub 280 miles from the North Pole in an encounter that would have been unimaginable a century ago. As the sea ice melts and the Arctic warms, many nations see not a climate warming, but an opportunity to exploit the region for resources. Photo by: U.S. Navy.
Read more: http://news.mongabay.com/2012/0213-hance_arctic_tippingpoints.html?utm_source=dlvr.it&utm_medium=twitter#ixzz1mNBb8eGOLast year the Arctic, which is warming faster than anywhere else on Earth due to... more-
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Arctic ice at record low: NSIDC director Serreze: 'ice free summer by 2030/downward spiral'
We’re at a record low Arctic sea ice extent and volume:
The area of the Arctic ocean at least 15% covered in ice is … lower than the previous record low set in 2007 – according to satellite monitoring by the US National Snow and Ice Data Centre (NSIDC) in Boulder, Colorado. In addition, new data from the University of Washington Polar Science Centre, shows that the thickness of Arctic ice this year is also the lowest on record.
In the past 10 days, the Arctic ocean has been losing as much as 150,000 square kilometres of sea a day, said Mark Serreze, director of the NSIDC.
“The extent [of the ice cover] is going down, but it is also thinning. So a weather pattern that formerly would melt some ice, now gets rid of much more. There will be ups and downs, but we are on track to see an ice-free summer by 2030. It is an overall downward spiral.“
The trend is painfully obvious to all who aren’t blinded by ideology. Indeed, many, including me, believe we’ll see virtually ice-free summers within a decade.
What do the experts — and deniers — predict for the September sea ice extent minimum? The Study of Environmental Arctic Change (SEARCH) has released its second Sea Ice Outlook report for July. Just about all the cryo-scientists think the Arctic will easily beat last year’s minimum:
More at the linkWe’re at a record low Arctic sea ice extent and volume: The area of the... more-
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Record low Arctic sea ice extent for January
During the Northern Hemisphere winter of 2010-2011, unusually cold temperatures and heavy snowstorms plagued North America and Europe, while conditions were unusually warm farther north. Now the U.S. National Snow and Ice Data Center (NSIDC) has reported that Arctic sea ice was at its lowest extent ever recorded for January (since satellite records began).
This image shows the average Arctic sea ice concentration for January 2011, based on observations from the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) aboard NASA's Aqua satellite.
Blue indicates open water; white indicates high sea ice concentrations; and turquoise indicates loosely packed sea ice. The yellow line shows the average sea ice extent for January from 1979 through 2000.
NSIDC reported that ice extent was unusually low in Hudson Bay, Hudson Strait, and Davis Strait in the early winter. Normally frozen over by late November, these areas did not completely freeze until mid-January 2011. The Labrador Sea was also unusually ice-free.
NSIDC offered two possible explanations. One reason is the Arctic Oscillation (AO), a seesaw pattern of differences in atmospheric pressure.
In "positive" mode, the AO includes high pressure over the mid-latitudes and low pressure over the Arctic, setting up wind patterns that trap cold air in the far North.
In "negative" mode, air pressure isn't quite as low over the Arctic and isn't quite as high over the mid-latitudes. This enables cold air to creep south and relatively warm air to move north.
The AO was in negative mode in December 2010 and January 2011, according to the U.S. National Oceanic and Atmospheric Administration (NOAA).
At mid-latitudes, the negative mode resulted in extremely cold temperatures and heavy snow in Europe and North America. At the same time, warm air over the Arctic impeded sea ice growth. NOAA has forecast that the AO should return to positive mode in February 2011, but for how long was unclear.
Another factor in the low Arctic sea ice extent, NSIDC explained, could be that the areas of open ocean were still releasing heat to the atmosphere. Due to its bright appearance, sea ice reflects most of the Sun's light and heat back into space. Dark ocean water, by contrast, absorbs most of that energy and reinforces the melting process.During the Northern Hemisphere winter of 2010-2011, unusually cold temperatures and... more-
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Arctic sees second lowest ice extent in November
This is also affected by the Beaufort Gyre.-
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NASA: Important climate change statistics
Current stats and effects of climate change that you need to know.-
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NASA Heads to Arctic to Measure Ice
NASA has a new tradition for the annual rites of spring: aerial assessments of Arctic sea ice, considered by many scientists to be ground zero for charting climate change.
"The polar regions are very sensitive to the changes in climate," said Michael Studinger, with the Goddard Earth Science and Technology Center at the University of Maryland. "Any kind of changes we see happening much sooner at the poles than at any other latitude."
Studinger is among a 35-member team of scientists, engineers, technicians and aircraft crew arriving in Greenland on Monday for a planned five-week field trip to collect information about polar ice. The campaign, called IceBridge, follows a similar expedition to Antarctica last October and November.
The missions, which are conducted aboard aircraft, are intended to replace data collected by an ice-monitoring satellite that failed last year. NASA plans to keep IceBridge going until a replacement spacecraft, called ICESat-2, is launched in 2015. ICESat is an acronym for Ice, Cloud and land Elevation Satellite.
The team was able to survey Arctic sea ice last year before ICESat's shutdown, which allowed researchers to calibrate information collected by the airborne instruments with the satellite data. Continuity is critical, since the point of the project is to assess on an annual basis changes in the amount and thickness of polar ice.
"We need to understand how the climate of Earth will respond in the future," Studinger told Discovery News. "It's a critical data set for computer models which are used to predict the sea level rise and temperature changes."
Laser measurements of Arctic ice since the early 1990s show the major edges of Greenland have been thinning, said NASA's Lora Koenig, with the Goddard Space Flight Center in Greenbelt, Md. "There also has been a decrease in the expanse of ice."NASA has a new tradition for the annual rites of spring: aerial assessments of Arctic... more-
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Arctic sea ice news from the NSIDC, not a bogus blog
In February, Arctic sea ice extent continued to track below the average, and near the levels observed for February 2007. Ice extent was unusually low in the Atlantic sector of the Arctic, and above normal in the Bering Sea. Meanwhile, Antarctic sea ice reached its summer minimum, near the average for 1979 to 2000.
Figure 1. Arctic sea ice extent for February 2010 was 14.58 million square kilometers (5.63 million square miles). The magenta line shows the 1979 to 2000 median extent for that month. The black cross indicates the geographic North Pole. Sea Ice Index data. About the data.
—Credit: National Snow and Ice Data Center
High-resolution image Overview of conditions
Arctic sea ice extent averaged for February 2010 was 14.58 million square kilometers (5.63 million square miles). This was 1.06 million square kilometers (409,000 square miles) below the 1979 to 2000 average for February, but 220,000 square kilometers (85,000 square miles) above the record low for the month, which occurred in February 2005.
Ice extent was above normal in the Bering Sea, but remained below normal over much of the Atlantic sector of the Arctic, including the Barents Sea, part of the East Greenland Sea, and in the Davis Strait.
Figure 2. The graph above shows daily sea ice extent as of March 2, 2010. The solid light blue line indicates 2009/2010; dashed green indicates 2006/2007; dark blue shows 2004/2005 (the record low for the month of February); and solid gray indicates average extent from 1979 to 2000. 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
High-resolution image
Conditions in context
During February 2010, ice extent grew at an average of 25,700 square kilometers (9,900 square miles) per day. Sea ice extent increased at a fairly steady rate in the early part of the month and then slowed after the middle of February. Ice extent remained more than two standard deviations below the 1979 to 2000 average throughout the month.
Figure 3. Monthly February ice extent for 1979 to 2010 shows a decline of 2.9% per decade.
—Credit: National Snow and Ice Data Center
High-resolution image February 2010 compared to past years
The average ice extent for February 2010 was the fourth lowest February extent since the beginning of the modern satellite record. It was 220,000 square kilometers (85,000 square miles) higher than the record low for February, observed in 2005. The linear rate of decline for February is now 2.9% per decade.
Figure 4. Map of air temperature anomalies for February 2010, at the 925 millibar level (roughly 1,000 meters or 3,000 feet above the surface) shows warmer than usual temperatures over the Arctic Ocean, with especially warm temperatures over Eastern Canada. Areas in orange and red correspond to strong positive (warm) anomalies. Areas in blue and purple correspond to negative (cool) anomalies.
—Credit: National Snow and Ice Data Center courtesy NOAA/ESRL Physical Sciences Division
High-resolution image Double-dip Arctic Oscillation
As noted previously, the Arctic Oscillation has been extremely negative this winter, with unusually high surface pressure over the Arctic Ocean. Following a strong negative phase from mid-December through mid-January, the AO briefly went positive, but then dipped again to a strongly negative phase. For more information on the Arctic Oscillation, see the NOAA Climate Prediction Center Web site.
The strong negative AO has contributed to cold temperatures throughout much of the U.S. and northern Europe, and the notable snow events in the eastern U.S. However, the impact on the Arctic has been quite different. First, a negative AO tends to bring warmer than normal temperatures to the Arctic. This factor contributed to the low ice conditions in the Atlantic side of the Arctic, discussed above. Second, the AO has a strong effect on Arctic sea ice motion. The pattern of winds associated with a strongly negative AO tends to reduce export of ice out of the Arctic through the Fram Strait. This helps keep more of the older, thicker ice within the Arctic. While little old ice remains, sequestering what is left may help keep the September extent from dropping as low as it did in the last few years. Much will depend on the weather patterns that set up this spring and summer.
Figure 5. The blue bars represent the average sea ice area on Canada's east coast for the first three weeks of February, from 1969 to 2009. The red bar shows the sea ice area for the same period in 2010.
—Credit: Data is from Environment Canada’s Canadian Ice Service
High-resolution imageIce conditions off the Canadian east coast
Tom Agnew, Stephen Howell, and Lionel Hache of Environment Canada note that average ice conditions off the east coast of Canada were at record lows during the first three weeks of February. Sea ice charts prepared by the Canadian Ice Service show that ice coverage in the Labrador Sea and Gulf of St. Lawrence was the lowest for that time period since analysts started charting the region in 1969. Mild temperatures and predominately northeasterly winds have prevented both the advance of ice down the Labrador coast and the formation of ice in the Gulf of St. Lawrence. These ice conditions are also linked to the strong negative Arctic Oscillation pattern.In February, Arctic sea ice extent continued to track below the average, and near the... more-
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Arctic Sea Ice: Freezing Toward a New Record?
With a month of freezing left, the Arctic seems to be trending toward yet another record.
After the third-straight year with record or near-record melting of Arctic sea ice, perhaps it's not a surprise that the annual re-freezing of the Arctic is continuing the consistently alarming trend.
December 2009 and January 2010 saw unusually warm conditions across the Arctic (even as North America got blasted with particularly cold air). The result? Arctic sea ice extent is now lower than it was at this point during the record-breaking 2006-2007 cycle that resulted in the record-lowest sea ice extent ever recorded in the summer of 2007. While both the summers of both 2008 and 2009 saw extreme melting far in excess of average, neither quite reached the extent of 2007.
The stage is being set for another significant melt in 2010, though there is still about a month of freezing to go. Arctic sea ice typically reaches its maximum extent for the year sometime around the end of February and the beginning of March.
Satellite records date to 1979, but ice cores and other data indicate that the rate of melting is unprecedented and can only be explained by the heat-trapping accumulation of greenhouse gases in the atmosphere. As ice melts, the darker water that is revealed absorbs more heat than the reflective ice, reinforcing the melting trend.
Greenpeace has predicted that most summer ice could be gone in five years, and the summer could be completely ice-free by 2050. While that may be an extreme view, the trend is heading in that direction eventually, and the extent of melting in the past three years was to an extent not expected for decades, under mainstream scientific predictions of just a few years ago.
As the ice melts, polar bear, Pacific walrus, ribbon seals and other species struggle for survival, and the potential for human use grows -- for oil and gas drilling, and for shipping through once ice-locked channels. More concerning for humans is this: As it becomes clear that the worst-case melting scenarios are taking place, does that mean that the worst-case predictions for other aspects of global warming are inevitable? Wildfires, droughts, crop failure, sea-level rise, massive rates of species extinctions ... each could appear more quickly, and have more severe impacts than the public expects.
Read more: http://www.thedailygreen.com/environmental-news/latest/arctic-sea-ice-47012703#ixzz0dq4fkk8VWith a month of freezing left, the Arctic seems to be trending toward yet another... more-
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September Global Surface Temperature Second Warmest Since 1880
The northeast is getting snow already, and low temperatures. Does this mean global warming is a myth? Not necessarily. A new analysis of global temperatures show that the combined global land and ocean surface temperature was the second warmest September on record, according to NOAA’s National Climatic Data Center in Asheville, N.C. Based on records going back to 1880, the monthly National Climatic Data Center analysis is part of the suite of climate services NOAA provides.
Global Temperature Highlights:
•The combined global land and ocean surface temperature was 1.12 degrees F above the 20th century average of 59.0 degrees F. Separately the global land surface temperature was 1.75 degrees F above the 20th century average of 53.6 degrees F.
•Warmer-than-average temperatures engulfed most of the world’s land areas during the month. The greatest warmth occurred across Canada and the northern and western contiguous United States. Warmer-than-normal conditions also prevailed across Europe, most of Asia and Australia.
•The worldwide ocean temperature tied with 2004 as the fifth warmest September on record, 0.90 degree F above the 20th century average of 61.1 degrees F. The near-Antarctic southern ocean and the Gulf of Alaska featured notable cooler-than-average temperatures.
•Arctic sea ice covered an average 2.1 million square miles in September - the third lowest for any September since records began in 1979. The coverage was 23.8 percent below the 1979-2000 average, and the 13th consecutive September with below-average Arctic sea ice extent.
•Antarctic sea ice extent in September was 2.2 percent above the 1979-2000 average. This was the third largest September extent on record, behind 2006 and 2007.
Image shows Global surface temperature anomalies (degrees F) for the month of September.
For more information: http://www.noaanews.noaa.gov/stories2009/20091015_sepglobalstats.htmlThe northeast is getting snow already, and low temperatures. Does this mean global... more-
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Arctic sea ice record low
While it's still too early to say whether the 2009 melt will exceed the record 2007 melt -- the annual low-point isn't reached until September -- the trend line for 2009 for the first time has dipped below 2007, according to the latest data from the National Snow and Ice Data Center.
Another record would be startling, but not surprising. Just 30% of the sea ice in the Arctic at the height of the winter freeze was thicker multi-year ice, leaving 70% susceptible to rapid melting. The amount of ice in the Arctic as of February 2009 -- the height of the annual freeze -- was the lowest on record. Most arctic scientists now say they expect an ice-free Arctic in summer within the next three decades -- far ahead of the projections in the last comprehensive United Nations report on global warming.
The melting of Arctic sea ice is one of the clearest signals of global warming, and a leading indicator of what is to come. The melting is also an example -- one of many -- of a positive feedback loop that scientists expect will accelerate global warming: As sea ice melts, the darker water that is exposed absorbs more of the sun's energy, which leads to warmer waters and more melting ice.
end of excerptWhile it's still too early to say whether the 2009 melt will exceed the record... more-
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