Sea Ice Decline Intensifies
Summer Arctic sea ice falls far below average for fourth year, winter ice sees sharp decline, spring melt starts earlier
This is a joint press release between the National Snow and Ice Data Center (NSIDC), a part of the Cooperative Institute for Research in Environmental Sciences at the University of Colorado, Boulder; NASA; and the University of Washington.
For the fourth consecutive year, NSIDC and NASA scientists using satellite data have tracked a stunning reduction in arctic sea ice at the end of the northern summer. The persistence of near-record low extents leads the group to conclude that Arctic sea ice is likely on an accelerating, long-term decline. “Considering the record low amounts of sea ice this year leading up to the month of September, 2005 will almost certainly surpass 2002 as the lowest amount of ice cover in more than a century," said Julienne Stroeve of NSIDC. If current rates of decline in sea ice continue, the summertime Arctic could be completely ice-free well before the end of this century. (Figure 1: September extent trend, 1978-2005).http://www.arctic.noaa.gov/detect/ice-seaice.shtml
The sea ice area for the Arctic shows near-record minimums for 2002-2006. The recent years represent a unique event because they show a year-to-year persistence of minimum ice extents (graph below). Sea ice area is now about 18% below the level of the 1980s and earlier.http://www.nasa.gov/vision/earth/environment/arcticice_decline.html
Satellites See a Double-Texas Sized Loss In Arctic Sea Ice
Scientists using satellite data have confirmed that the amount of sea ice that floats in the chilly Arctic is much less than it used to be, and that's probably because of warmer Arctic temperatures.
Each year, during the month of September, the amount of sea ice floating in the Arctic Ocean is typically at its lowest amount for the entire year. This year, and all the way back to 2002, the amount of sea ice has been 20 percent less than the average amount seen normally between 1979 and 2000.
Satellites helped scientists learn that there was about 502,000 square miles less sea ice each September since 2001 than there typically was in previous Septembers.http://www.gfdl.noaa.gov/~kd/KDwebpages/NHice.html
Arctic sea ice changes in gfdl climate change scenario experiments
GFDL model results suggest that the Arctic is a region where one can look for potentially dramatic climate change signals in the 21st century. On this page, we show some results from coupled climate model experiments conducted at NOAA's Geophysical Fluid Dynamics Laboratory (GFDL) in Princeton, New Jersey.
using GFDL's current state-of-the-art climate model known as the GFDL CM2.1 model.
Michael McCarthy, Environment Editor, "Vast ice shelf collapses in the Arctic", Independent, December 30, 2006, http://news.independent.co.uk/environment/article2112609.ece
A vast ice shelf in the Canadian Arctic has broken up, a further sign of the astonishing rate at which polar ice is now melting because of global warming.
The Ayles ice shelf, more than 40 square miles in extent - over five times the size of central London - has broken clear from the coast of Ellesmere Island, about 500 miles south of the North Pole in the Canadian Arctic, it emerged yesterday.
The broken shelf has formed an ice island, in what a leading scientist described as a "dramatic and disturbing event", citing climate change as the cause. The news caps a dramatic year of discovery about just how quickly the polar ice is disappearing.
It comes as America's leading climate scientist, James Hansen, warns in today's Independent that the Earth is being turned into "a different planet" because of the continuing increase in man-made emissions of greenhouse gases. The break-up of the Ayles shelf occurred 16 months ago, in an area so remote it was not at first detected. "This is a dramatic and disturbing event," said Professor Warwick Vincent of Laval University in Quebec City. "It shows that we are losing remarkable features of the Canadian North that have been in place for many thousands of years."Ice shelves float on the sea, but are connected to land (as opposed to ice sheets, which are wholly land-based). In the past five years, several ice shelves along the fringes of the Antarctic peninsula have started to become unstable or break up. The most spectacular was the 2002 collapse of the Larsen B ice shelf, the size of Luxembourg.
Until now, there had not been a similar event among the six major shelves remaining in Canada's Arctic, which are packed with ancient ice that is more than 3,000 years old.
Professor Vincent, who studies Arctic ecosystems, travelled to the newly formed ice island and was amazed at what he saw. "It's like a cruise missile has come down and hit the ice shelf," he said. "Unusually warm temperatures definitely played a major role. It is consistent with climate change." The collapse was picked up by the Canadian Ice Service, which notified Luke Copland, head of the new global ice laboratory at the University of Ottawa. Using US and Canadian satellite images, as well as seismic data - the event registered on earthquake monitors more than 150 miles away - Professor Copland discovered that the ice shelf collapsed in the early afternoon of 13 August 2005. Scientists were surprised at the speed of the event, Professor Copland said - it took less than an hour.
There have already been several disturbing indications this year that the Arctic ice is melting at a much faster rate than expected. In September, two Nasa reports showed a great surge in the disappearance of the winter sea ice over the past two years, with an area the size of Turkey disappearing in 12 months.
Something weird happens with reports on Antarctic sea ice: they speak bouth mouths simultaneously like Laura wrote!http://iup.physik.uni-bremen.de:8084/amsr/amsre.html
Daily Updated Sea Ice Maps, Univ. Of Bremen, Germany (Arctic, Antarctic) from satellite AMSR-E
this one is quite interesting:http://www.terradaily.com/news/antarctic-05o.html
New Melting Moment
The collapse of a huge ice shelf in Antarctica in 2002 has no precedent in the past 11,000 years, according to a study that points the finger at global warming. Measuring some 3,250 sq km in area and 220m thick, the Larsen B iceshelf broke away from the eastern Antarctic Peninsula in 2002, eventually disintegrating into giant icebergs.
By chance, a US-led team of geologists had gathered a rich harvest of data around the iceshelf just before the spectacular collapse, including six cores that had been drilled into marine sediment. The cores contain the remains of plankton and algae imbedded in layers of minerals, and their radiocarbon and oxygen isotopes provide clues about ice cover and climate change over the millennia.
The researchers, reporting in Nature, the British science weekly, say that since the end of the last Ice Age, some 11,000 years ago, the iceshelf had been intact but had slowly thinned, by several dozen metres. Its coup de grace came from a recent but decades-long rise in air temperature, they say. "The modern collapse of the LIS-B [Larsen B iceshelf] is a unique event within the Holocene," they write.
"The LIS-B eventually thinned to the point where it succumbed to the prolonged period of regional warming now affecting the entire Antarctic Peninsula region." The Holocene is the period of relatively balmy weather that followed the last Ice Age. The research is the latest in a series of studies to sound the alarm about the effects of climate change in Antarctica, where the bulk of the world's freshwater is locked up.
The Antarctic Peninsula, which juts northwards out of West Antarctica, is considered a warming hot-spot.
Over the past half century, temperatures in the peninsula have risen by around two degrees Celsius.
In recent years, the peninsula has lost ice shelves totalling more than 12,500 sq km, equivalent to four times the area of Luxembourg.
Of the 244 glaciers that drain inland ice and feed these shelves, 87 per cent have fallen back since the mid-1950s, according to a British study published in April.
Global warming, also called the greenhouse effect, is caused by carbon gases mostly discharged by burning oil, gas and coal, that trap the Sun's heat. But Earth's climate also goes through natural oscillations of warming and cooling, resulting in Ice Ages and the milder interglacial periods in between.
The new study does not say that global warming caused by human activity was responsible for the Larsen B's demise. However, it refers to a steep rise in the temperatures over the past several decades, a phenomenon that climatologists concur was unleashed by fossil fuels.
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Overally, i have an impression that there is a mask of a peer-reviewed science in recent reports on climate change, it's like a terrible labirinth
one has to go through ... only to get lost!!