Posted on 03/03/2006 11:03:07 AM PST by Ernest_at_the_Beach
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Seasonal results from the survey
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ERS radar altimeters work by sending 1800 separate radar pulses down to Earth per second then recording how long their echoes take to bounce back 800 kilometres to the satellite platform. The sensor times its pulses' journey down to under a nanosecond to calculate the distance to the planet below to a maximum accuracy of two centimetres.
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ERS in orbital configuration
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The result is a scientifically valuable long-term dataset covering Earth's oceans and land as well as ice fields – which can be used to reduce uncertainty about whether land ice sheets are growing or shrinking as concern grows about the effects of global warming.
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Greenland's east coast seen by Envisat
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The influx of freshwater into the North Atlantic from any increase in melting from the Greenland Ice Sheet could also weaken the Gulf Stream, potentially seriously impacting the climate of northern Europe and the wider world.
Efforts to measure changes in the Greenland Ice Sheet using field observations, aircraft and satellites have improved scientific knowledge during the last decade, but there is still no consensus assessment of the ice sheet's overall mass balance. There is however evidence of melting and thinning in the coastal marginal areas in recent years, as well as indications that large Greenland outlet glaciers can surge, possibly in response to climate variations.
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Overall elevation changes over 11 years
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By combining tens of millions of data points from ERS-1 and ERS-2, the team determined spatial patterns of surface elevation variations and changes over an 11-year period.
The result is a mixed picture, with a net increase of 6.4 centimetres per year in the interior area above 1500 metres elevation. Below that altitude, the elevation-change rate is minus 2.0 cm per year, broadly matching reported thinning in the ice-sheet margins. The trend below 1500 metres however does not include the steeply-sloping marginal areas where current altimeter data are unusable.
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Changes in Greenland Ice Sheet elevation, above and below 1500 m
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The team, led by Professor Ola M. Johannessen of NERSC, ascribe this interior growth of the Greenland Ice Sheet to increased snowfall linked to variability in regional atmospheric circulation known as the North Atlantic Oscillation (NAO). First discovered in the 1920s, the NAO acts in a similar way to the El Niño phenomenon in the Pacific, contributing to climate fluctuations across the North Atlantic and Europe.
Comparing their data to an index of the NAO, the researchers established a direct relationship between Greenland Ice Sheet elevation change and strong positive and negative phases of the NAO during winter, which largely control temperature and precipitation patterns over Greenland.
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Greenland elevation changes plotted against NAO index
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He cautioned that the recent growth found by the radar altimetry survey does not necessarily reflect a long-term or future trend. With natural variability in the high-latitude climate cycle that includes the NAO being very large, even an 11-year long dataset remains short.
"There is clearly a need for continued monitoring using new satellite altimeters and other observations, together with numerical models to calculate the Greenland Ice Sheet mass budget," Johannessen added.
Such models agree with the new observational results. However after that threshold is reached, potentially within the next hundred years, losses from melting would exceed accumulation from increases in snowfall – then the meltdown of the Greenland Ice Sheet would be on.
A paper published in Science in June this year detailed the results of a similar analysis of the Antarctic Ice Sheet based on ERS radar altimeter data, carried out by a team led by Professor Curt Davis of the University of Missouri-Columbia.
The results showed thickening in East Antarctica on the order of 1.8 cm per year, but thinning across a substantial part of West Antarctica. Data were unavailable for much of the Antarctic Peninsula, subject to recent ice sheet thinning due to regional climate warming, again because of limitations in current radar altimeter performance.
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CryoSat was lost on launch
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Efforts are currently underway to investigate the possibility of building and flying a CryoSat-2, with a decision to be taken by the end of the year. In the meantime, the valuable climatological record of ice sheet change established by ERS and Envisat will continue to be extended.
Bush's fault!!!
relocate the polar bears? Maybe just the Canadians.
Its all suppose to be melting away!!!!!!!
You never read about what catastrophe would befall us if the ocean levels DROP because too much water gets frozen in Greenland.
It would be hilarious if we found out that the entire interior of the greenland ice sheet was only 3 feet thick, with a huge empty space underneath because of melting from underground heat sources. I know we know that isn't true, I'm just saying it would be funng.
What's AL Gore going to do now.....?
That's it...its over..the global warming is over..I called it first..now I have to write a book
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Last Updated: Sunday, 22 May 2005, 14:32 GMT 15:32 UK 
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Antarctic buffers sea level rise
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This bulge, which was recorded by satellite, may temporarily buffer rising sea levels, they believe. Antarctica's "weight gain" is due to extra snowfall, caused by rising temperatures, the US-UK team thinks. However, the scientists worry the overall mass of the Antarctic may be decreasing because ice near the coasts is melting, possibly at a greater rate. Understanding Antarctica The Antarctic contains the bulk of our planet's ice, so understanding its growth or shrinkage is critical to predicting future sea level changes.
Sea levels are currently rising at about 1.8mm per year, largely because ice sheets in polar regions are melting, the Intergovernmental Panel on Climate Change (IPCC) has said. However, the panel also predicted that global warming would lead to an increase in snow fall over the Antarctic, because warmer air leads to more evaporation and precipitation. Scientists from both sides of the Atlantic tested this theory by analysing the thickness of Antarctica's central ice sheets, using satellite radar altimetry measurements. They discovered that East Antarctica thickened at an average rate of 1.8cm per year between 1992 and 2003. The region, which covers 75% of Antarctica's total land area, holds 85% of the total ice volume. "The East Antarctic ice sheet absorbed ocean mass in the form of snowfall so, as a result, it slowed sea level rise," Curt Davis, of the University of Missouri, US, told the BBC News website. "It is a modest slowing, but it is somewhat surprising because all the other terrestrial ice masses are contributing to sea levels. This is the only one that is absorbing mass rather than contributing to it." Although Greenland may also be experiencing increased precipitation, Professor Davis says, the result is not the same. "In Greenland we are getting more snowfall but Greenland is a lot warmer," he explained. "So whenever you get an increase in temperature in Greenland, you also get increased melt." Finite effect Even though Antarctica is, at the moment, taking the edge off the effects of a warming global climate, we should not take too much comfort, say the researchers. Snowfall over East Antarctica will not continue to increase indefinitely in a warming world but, conversely, ice melt will accelerate proportionately with every degree of rising temperature, swelling oceans further. "The effect will only work for a finite period of time," Professor Davis said. "Eventually, the snow will start to melt." Also, the overall mass of Antarctica may be decreasing, because coastal melt may be happening faster than internal ice sheet gain. "Since sea levels are rising, that would be a reasonable assumption to make, although we don't know for sure," added Professor Davis. The instruments used in this particular study were unable to monitor the coastal regions because they could not cope with the steep terrain. However, the European Space Agency satellite CryoSat, due to be launched in the next year, should be up to the task, Professor Davis believes. "CyroSat has some special processes that allow it to do a better job," he said. "Over the next few years we should get a more definitive answer."
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The amount of crap being peddled by the Global Warming crowd is mindboogling.....
"Such models agree with the new observational results. However after that threshold is reached, potentially within the next hundred years, losses from melting would exceed accumulation from increases in snowfall – then the meltdown of the Greenland Ice Sheet would be on."
Here we go again, the most up-to-date data fails to support the melting theory so we stretch the time frame out another few decades to a hundred years, comfortably beyond any reader's likely long-term memory.
Forgot sarcasm tag :P
Using the above reasoning will allow one to defrost a freezer; turn off the cooling and the frost gradually melts away.
However, the atmosphere's power is the sun and we have no way to turn it off, turn it down, or turn it up.
After 11 years of study, the numbers show that no net loss is taking place, and one might think that a financially prudent thing to do would be to turn off the money spigot.
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New York Times - Two new satellite surveys show that warming air and water are causing Antarctica to lose ice faster than can be replenished by interior snowfall and thus are contributing to rising global sea levels. The studies ... Antarctic ice sheet is shrinking Scientists find Antarctic ice shrank significantly |
See the links at post #16 for those stories,,,they have more....
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From
Not by Fire but by Ice
THE NEXT ICE AGE - NOW!
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What a bunch of double talk - 17 Feb 06 - Here’s yet another article
screaming about how “global warming” is causing twice as much ice from the
Greenland ice cap to advance toward the sea than was flowing toward the sea
five years ago.
For years we've been told that receding glaciers are evidence of global warming.
Now we’re being told that advancing glaciers are evidence of global warming.
What a bunch of double talk.
Advancing glaciers are NOT evidence of global warming, advancing glaciers are an
indicator that we're headed into an ice age. Glaciers advance toward the sea because
increased snowfall makes them heavier at the top and pushes them out at the sides.
It's truly simple. Any geology 101 course will tell you that the concept of glacier
mass balance suggests that a glacier is influenced by two processes: accumulation
and ablation. If accumulation exceeds ablation the glacier surges forward. If ablation
exceeds accumulation the glacier retreats.
(See Greenland Icecap Growing Thicker)
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Climate change: On the edge
A satellite study of the Greenland ice cap shows that it is melting far faster than scientists had feared - twice as much ice is going into the sea as it was five years ago. The implications for rising sea levels - and climate change - could be dramatic.
Yet, a few weeks ago, when I - a Nasa climate scientist - tried to talk to the media about these issues following a lecture I had given calling for prompt reductions in the emission of greenhouse gases, the Nasa public affairs team - staffed by political appointees from the Bush administration - tried to stop me doing so. I was not happy with that, and I ignored the restrictions. The first line of Nasa's mission is to understand and protect the planet.
Abstract: Changes in ice mass are estimated from elevation changes derived from 10.5 years (Greenland) and 9 years (Antarctica) of satellite radar altimetry data from the European Remote-sensing Satellites ERS-1 and -2. For the first time, the dH/dt values are adjusted for changes in surface elevation resulting from temperature-driven variations in the rate of firn compaction. The Greenland ice sheet is thinning at the margins (+42 +/- 2 Gt a-1 below the equilibrium-line altitude (ELA)) and growing inland (+53 +/- 2 Gt a-1 above the ELA) with a small overall mass gain (+11 +/- 3 Gt a-1; +0.03 mm a-1 SLE (sea-level equivalent)). The ice sheet in West Antarctica (WA) is losing mass (-47 +/- 4 Gt a-1) and the ice sheet in East Antarctica (EA) shows a small mass gain (+16 +/- 11 Gt a-1) for a combined net change of -31 +/- 12 Gt a-1 (+0.08 mm a-1 SLE). The contribution of the three ice sheets to sea level is +0.05 +/- 0.03 mm a-1. The Antarctic ice shelves show corresponding mass changes of -95 +/- 11 Gt a-1 in WA and +142 +/- 10 Gt a-1 in EA. Thinning at the margins of the Greenland ice sheet and growth at higher elevations is an expected response to increasing temperatures and precipitation in a warming climate. The marked thinnings in the Pine Island and Thwaites Glacier basins of WA and the Totten Glacier basin in EA are probably ice-dynamic responses to long-term climate change and perhaps past removal of their adjacent ice shelves. The ice growth in the southern Antarctic Peninsula and parts of EA may be due to increasing precipitation during the last century.
a-1 is per annum, i.e. per year.
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This is the only place that is absorbing mass rather than contributing to it 
