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Post by sigurdur on Aug 20, 2010 3:15:35 GMT
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Post by steve on Aug 20, 2010 6:38:36 GMT
I loved this part:
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Post by inverse on Aug 20, 2010 6:45:49 GMT
Lets hope the Antarctic does not have a 50 year cycle of expand and contract, if we are now at the peak we could have 50 years of warming scare to put up with. Then NSIDC will probably highlight the Antarctic melt and sideline the Arctic Ice growth.
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Post by byz on Aug 20, 2010 7:11:36 GMT
From other articles I've read it appears that as the Arctic warms Antarctica cools and then it the opposite happens. This is due to changes in water movement in the oceans.
At present Antarctica is at a high so it will be interesting to see if this actually happens as they flip back again.
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Post by poitsplace on Aug 20, 2010 7:35:36 GMT
From other articles I've read it appears that as the Arctic warms Antarctica cools and then it the opposite happens. This is due to changes in water movement in the oceans. At present Antarctica is at a high so it will be interesting to see if this actually happens as they flip back again. Well I should think that's obvious...as the arctic recovers and the antarctic ice extent shrinks, "scientists" will rather conveniently find that antarctic ice extent is the one true measure of global warming.
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Post by steve on Aug 20, 2010 8:06:09 GMT
Numerous independent studies are showing that the Antarctic continent is losing ice mass, so the assumption that the sea ice changes are symptomatic of a cooling Antarctica should not necessarily follow.
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Post by icefisher on Aug 20, 2010 8:28:39 GMT
Numerous independent studies are showing that the Antarctic continent is losing ice mass, so the assumption that the sea ice changes are symptomatic of a cooling Antarctica should not necessarily follow. How were these parameters measured Steve? How many studies are we talking about? And how was independence ensured?
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Post by steve on Aug 20, 2010 9:06:04 GMT
The GRACE satellite that looks at gravitational changes, satellite altimetry has measured thinning of glaciers, and measurements of sea-level rise combined with changes in ocean heat content suggest that the observed rise in sea level is mostly related to land ice loss (and Greenland melting cannot account for it all). That's three independent ways (looked at with more than 3 separate studies).
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Post by tobyglyn on Aug 20, 2010 10:00:20 GMT
Have a look at wuwt both of the main authors have posted there and there are two different threads discussing and um, eviscerating it.
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Post by nautonnier on Aug 20, 2010 10:56:26 GMT
The GRACE satellite that looks at gravitational changes, satellite altimetry has measured thinning of glaciers, and measurements of sea-level rise combined with changes in ocean heat content suggest that the observed rise in sea level is mostly related to land ice loss (and Greenland melting cannot account for it all). That's three independent ways (looked at with more than 3 separate studies). "The idea that circulation in the Earth's mantle can significantly affect sea levels has been gaining momentum, says Clint Conrad of the University of Hawaii in Honolulu. Changes like those seen in Scotland may mean that records of global sea levels on Earth, which track climate swings and plate tectonics, may need to be re-examined to take account of this mechanism."www.newscientist.com/article/mg20727674.800-giant-hand-pushed-up-coast-of-scotland.html" GRACE is showing ice loss in places that stay incredibly cold, all year round. The problem with GRACE is that it measures gravity, not ice. Changes in gravity can be due to a lot of different things beneath the surface of the ice. Antarctica has active magma chambers. Plate tectonics and isostasy also cause gravity changes"wattsupwiththat.com/2010/06/29/amazing-grace/There needs to be some care with metrics that can measure several things. Sea level can alter because the land moved, gravity changes in one part of the world are 'magma and tectonic shifts' in another part of the world they are 'ice loss'. This sounds like the metrics can be anything the 'scientist' wants them to be. If you are an AGW proponent then obviously your bias states it must be sea level rise - but a geologist that currently has no AGW bias would say its volcanism with moving magma and land lifting and falling. Its a case of believe what you want to believe - there are two hypotheses and the metrics do not indicate which is false.
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Post by steve on Aug 20, 2010 11:05:52 GMT
nautonnier,
Obviously, having three separate strands of evidence helps given that each strand may be open to interpretation.
Steve Goddard's post stands entirely on his complaint that GRACE is showing ice loss in cold places with the implication that ice cannot be lost in cold places. This implication is wrong. An alternative explanation to his post is that, notwithstanding the uncertainties in temperatures, the glaciers are indeed moving quicker and losing more ice by calving.
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Post by icefisher on Aug 20, 2010 11:10:48 GMT
The GRACE satellite that looks at gravitational changes, satellite altimetry has measured thinning of glaciers, and measurements of sea-level rise combined with changes in ocean heat content suggest that the observed rise in sea level is mostly related to land ice loss (and Greenland melting cannot account for it all). That's three independent ways (looked at with more than 3 separate studies). Oh so they didn't even measure the antarctic! Its just the plug figure in the numerous independent studies! Numerous? So 3 studies not even of the antarctic is in your mind numerous antarctic studies? In the common English language 3 is not numerous it is a "few". Thats less than several but more than one. And several means more than 2 or 3 but not many. And numerous means a lot or many. Independent? Gee you didn't say a word about that. How was that figured? Fact is we are learning more about complexity of the topic of the height of the surface of the earth than we are learning about the causes of changes in surface heights at this point in time. The most remarkable differences in surface height are proving to be plate boundaries, not ice sheets. Its definitely fun to go on a blog and blurt out a few unfounded theories in support of your Grand Theory and support them by exaggerations of how your conclusions have been replicated by numerous independent sources. . . .but pretty clearly none of that stands up to scrutiny. . . .and what suffers as a result? Do you have any ideas on that?
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Post by steve on Aug 20, 2010 11:41:31 GMT
Icefisher, re-read my post....a....little...more...slow...ly. It was actually self-consistent. Since you only listen to evidence that supports your preconceived and fixed views, listing a few papers isn't going to help. But here goes anyway. Two studies about two techniques: Nature Geoscience 2, 859 - 862 (2009) Published online: 22 November 2009 | doi:10.1038/ngeo694 Accelerated Antarctic ice loss from satellite gravity measurements J. L. Chen1, C. R. Wilson1,2, D. Blankenship3 & B. D. Tapley1 Nature Geoscience 1, 106 - 110 (2008) Published online: 13 January 2008 | doi:10.1038/ngeo102 Recent Antarctic ice mass loss from radar interferometry and regional climate modelling Eric Rignot et al A review article of other numerous studies: journals.cambridge.org/action/displayAbstract?fromPage=online&aid=6215004
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Post by hunterson on Aug 20, 2010 12:55:55 GMT
If the Antarctic was losing ice mass, there would be evidence of it from other than a gravity sensor that does not measure ice but gravity fluctuations. The Antarctic sea ice is not evidence of continental ice loss. That is why the Curry paper was written. The AGW promoters are grasping for rationalizations to explain increased sea ice. the problem for the recent Curry explanation is that it is evidence free: the temperature data they use is cherry picked for ending in 1999, avoiding the inconvenient drop in southern ocean temps over the last ten years or so while the sea ice has expanded. Whatever is going on in world sea ice dynamics, it is not well explained by the CO2 obsession. But since we are in the age of CO2 obsession, we will just have to wait until cooler heads emerge to look and find actual causes.
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Post by william on Aug 20, 2010 13:19:28 GMT
Steve,
As the Antarctic Ice Sheet is cooling, how does one explain GRACE's measurement? i.e. What is causing the ice sheet mass of an ice sheet that has an average thickness of 1.5 kilometer and a year average temperature around -40C?
It seems physically impossible for the Antarctic Ice Sheet to lose mass as temperatures on the ice sheet are significantly below freezing for the entire year.
Something else besides ice sheet mass appears to be affecting the GRACE measurement.
The change is very, very rapid as compared to geological process which rules out a geological explanation.
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