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Post by marchesarosa on Jun 21, 2011 23:17:04 GMT 1
www.the-cryosphere-discuss.net/5/1311/2011/tcd-5-1311-2011.pdfSmedsrud, L. H., Sirevaag, A., Kloster, K., Sorteberg, A., and Sandven, S.: Recent wind driven high sea ice export in the Fram Strait contributes to Arctic sea ice decline, The Cryosphere Discuss., 5, 1311-1334, doi:10.5194/tcd-5-1311-2011, 2011 Arctic sea ice area decrease has been visible for two decades, and continues at a steady rate. Apart from melting, the southward drift through Fram Strait is the main loss. We present high resolution sea ice drift across 79° N from 2004 to 2010. The ice drift is based on radar satellite data and correspond well with variability in local geostrophic wind. The underlying current contributes with a constant southward speed close to 5 cm s-1, and drives about 33 % of the ice export. We use geostrophic winds derived from reanalysis data to calculate the Fram Strait ice area export back to 1957, finding that the sea ice area export recently is about 25 % larger than during the 1960s. The increase in ice export occurred mostly during winter and is directly connected to higher southward ice drift velocities, due to stronger geostrophic winds. The increase in ice drift is large enough to counteract a decrease in ice concentration of the exported sea ice. Using storm tracking we link changes in geostrophic winds to more intense Nordic Sea low pressure systems. Annual sea ice export likely has a significant influence on the summer sea ice variability and we find low values in the 60s, the late 80s and 90s, and particularly high values during 2005–2008. The study highlight the possible role of variability in ice export as an explanatory factor for understanding the dramatic loss of Arctic sea ice the last decades. ------ NASA scientists proposed this factor was important several years ago and I posted their finding it in several places, most recently at reply #9 on the "Arctic Warms" thread here radio4scienceboards.proboards.com/index.cgi?board=witter&action=display&thread=599. This climatic effect of wind on Arctic sea ice has now been written up in the peer-reviewed paper above. Enjoy! Just another detail to add to the rather small cache of knowledge we possess about natural variation.
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Post by speakertoanimals on Jun 23, 2011 1:24:10 GMT 1
So, wind contributes to sea-ice loss, but doesn't totally explain it. Plus we have the effect of AGW on the wind patterns themselves, lets not forget that!
What I don't see here is anything saying -- it ain't warming, just the wind.
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Post by principled on Jun 23, 2011 9:37:59 GMT 1
STA
But it is another piece of evidence to show that we are far from understanding the interplay of all the factors that affect the observations scientists are making. Is this and important discovery? I don't know in scientific terms, but it is important in showing that the certainty expressed previously that x and y are indicators only of AGW are not always as certain as AGW activists have made them out to be.
P
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Post by marchesarosa on Jun 25, 2011 21:59:08 GMT 1
Precisely, principled.
The more we learn about natural variation the better.
If as much cash had been poured into studies of natural variation as have been poured into AGW we would be better informed, undoubtedly.
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Post by marchesarosa on Jun 27, 2011 19:18:44 GMT 1
Quote of the Week:
“…it was clear that the first and greatest need was to establish the facts of the past record of the natural climate in times before any side effects of human activities could well be important.”
HH Lamb, Founder, on establishing the Climatic Research Unit at University of East Anglia [H/t Tim Ball]
------- This was from the era before mediocre IPCC climatologists thought they were saviours of mankind.
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Post by marchesarosa on Jun 30, 2011 14:23:45 GMT 1
This as about Antarctica but I'm sure stu won't mind. Geology (Geological Society of America) Reduced ice extent on the western Antarctic Peninsula at 700–970 cal. yr B.P.July 2010 B.L. Hall, T. Koffman, and G.H. Denton Abstract
Rapid warming and consequent ice-shelf collapse have focused attention on the glacial record of the Antarctic Peninsula. Here, we present the first record of terrestrial organic material exposed by recently retreating ice that bears on past glacier extent and climate in this sensitive region. Radiocarbon dates show that ice on Anvers Island was at or behind its present position at 700–970 cal. yr B.P., coincident with ice reduction elsewhere in the Southern Hemisphere. Moreover, the data indicate that present reduced ice extent on the western Antarctic Peninsula is not unprecedented and is similar to that experienced during at least three periods in the last 5600 yr.geology.geoscienceworld.org/cgi/content/abstract/38/7/635Sorry, alarmists, you should have heeded Hubert's message above - FIRST RULE OF CLIMATOLOGY - discover the natural climate cycles and events first. It's just MORE of that inconvenient EVIDENCE revealed underneath retreating ice! Remember how kiteman was so upset at the mention of tree stumps and neolithic remains underneath his fav retreating glacier in Switzerland? There's MORE where that came from, fraid, ol' pal!
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Post by nickrr on Jun 30, 2011 19:35:13 GMT 1
Oh dear - same mistake over and over again.
I doesn't matter that the current conditions have existed before. The one thing we know for certain is that they weren't caused by humans. The evidence shows that the current warming almost certainly is. What's more, we know that the current reason for warming isn't going away so it's very unlikely that the current warming trend will reverse, unlike during previous periods of reduced ice cover.
Why can't you get it into your head that the argument "climate has changed before so it must be alright now" is fallacious. It's really not that difficult to understand!
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Post by speakertoanimals on Jun 30, 2011 20:09:42 GMT 1
Except why do you think people DON'T study natural variation?
As has been pointed out before, when people study whatever it is, they have to look at present conditions (where one hypothesis is that human activity has caused a change that wouldn't have occured naturally), and they look at past conditions, where human factors didn't operate. Hence it is unavoidable that at some point they will be forced to confront the question -- what is natural variability WITHOUT human interaction, and is what we see now explainable by that?
Of course, the answer that people keep getting is that natural variability can't explain what we see now.
Why keep pretending that all these scientists just keep ignoring natural variability as a possible explanation? It just isn't true that that is the way the science has been done and is being done.
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Post by StuartG on Jul 1, 2011 0:25:09 GMT 1
#21 "I doesn't matter that the current conditions have existed before. The one thing we know for certain is that they weren't caused by humans." If the current conditions have existed before, and humans didn't cause them, then something else did. So if those conditions are current as well, then perhaps that something else is still present.
"The evidence shows that the current warming almost certainly is [man]." Not if that which is now current has also existed before without man.
"we know that the current reason for warming isn't going away so it's very unlikely that the current warming trend will reverse" IF, it's known that the current reason for warming isn't going away and is unlikely to be reversed, then there's nothing man do to prevent this. To be this sure then the likely end must have been calculated/ or calculated to be likely unending. If that is so then did they give a date, or at least an indication of when this might happen?
StuartG
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Post by marchesarosa on Jul 1, 2011 4:40:06 GMT 1
"All these scientists", STA? Who on earth are you talking about? Which scientists? I'd love you tell me which IPCC scientists are studying "natural variation" because my guess would be that NONE of them are. In fact, the IPCC was set up SOLELY to demonstrate Anthropogenic Global Warming - that is its rationale, its function and its objective - nothing else. The clique stopped looking when they found the pre-determined answer.
Certainly, other studies relevant to climate are done in other disciplines and for other organisations, and I regularly report them, but they are NOT from the IPCC and its tame "climatology" hacks, no sirree, nor are they included in IPCC reports. The IPCC takes YOUR view, STA and nickrr and ListenerLouise, in fact you could all be IPCC parrots for all I know, with your silly claim that whatever caused previous climate variation (i.e. warming) isn't the cause of the purported "current" warming.
I don't buy that because lots of reputable scientists don't buy it either and they are FAR more convincing than you, STA et al, with your constant repetition of orthodoxy and not an atom of wisdom, originality or independence in your silly heads.
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Post by marchesarosa on Jul 1, 2011 5:11:16 GMT 1
Well, nickrr, if it's a mistake to consider natural climate variation first before allocating any aspect of it to mankind it's a mistake I am happy to share with HH Lamb, father of UK climatology and plenty of other eminent scientists.
Whose your fav "climatologist", nickrr, - Keith Briffa, Michael Mann or Phil Jones?
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Post by nickrr on Jul 1, 2011 18:04:24 GMT 1
True, except that there is no good evidence that the current warming is due to non-human factors and very good evidence that it is. Therefore the fact that some other factor caused warming in the past is no reason why it can't now be caused by humans.
Of course there is if the problem is caused by man!
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Post by nickrr on Jul 1, 2011 18:08:22 GMT 1
Of course it isn't. Your usual tactic of trying to claim someone said something they didn't and then trying to rubbish it.
That's your problem. You rely on guesses and intuition rather than facts.
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Post by StuartG on Jul 1, 2011 19:17:10 GMT 1
"no good evidence that the current warming is due to non-human factors " That Man is making some effect on the environment is true, but how much is the debate. There are too many unknowns to say with enough confidence, at present. If some action were taken now, with the present knowledge, damage may result from that. "is no reason why it can't now be caused by humans." the 'reciprocal' to that is also not unreasonable, "is no reason why it can now be caused by humans."
"Of course there is if the problem is caused by man!" You said earlier... "we know that the current reason for warming isn't going away" and that "it's very unlikely that the current warming trend will reverse" so whether we did or did not cause any intervention is pointless.
Lets say that Your point of view is all true, how would, and what action, would be taken? StuartG
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Post by louise on Jul 1, 2011 20:21:22 GMT 1
The more we learn about natural variation the better. I absolutely agree and so do all climate scientists. To claim that this is not being investigated with vigour and rigour is just not true as I have pointed out before. At the risk of being accused of being rude and posting a large chunk of text, I'll risk it here as some folk don't seem to be able to follow the links to learn this for themselves. The links to the scientific studies that have looked at natural variation can be found in the original article at www.skepticalscience.com/global-warming-natural-cycle.htm
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