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Post by nautonnier on Aug 22, 2010 22:04:19 GMT
"Which of course is the only place on earth we aren't taking any real readings" vs "Here look at these actual arctic measurements." Both comments by icefisher on this thread and this page. As it so incredibly important, how many real temperature readings does GISS have from the Arctic and Antarctic?
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Post by icefisher on Aug 22, 2010 22:39:14 GMT
"Here look at these actual arctic (SURFACE TEMPERATURE) measurements." vs "Which of course (THE TROPOSPHERE) is the only place on earth we aren't taking any real readings"
Both comments by icefisher on this thread and this page.Just more of your moronic blabberings Socold. If you could read you would know the former statement was with regards to DMI surface readings which show the arctic cooling over at least the past 15 years AND the latter statement was in response to your claim that surface temperatures were low due to ice melting and the heat was in the troposphere. "The observations presented in the second graph show faster warming in the troposphere than the surface during summer in the arctic. "In describing your hypothesis you provided graphs of model outputs for the troposphere over the Arctic and proclaimed that as being the place of warming in the Arctic. . . . a place that there are no thermometers nor satellites doing any measurements. You went on to explain negative feedback as limiting the warming at the surface. I pointed out if the negative feedback is stronger than the forcing its not feedback at all but instead an elemental forcing not included in the model. The surface temperature record helps validate that. Your response with model output of the troposphere is meaningless as you have zero evidence for that hypothesis.
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Post by astroposer777 on Aug 22, 2010 22:43:11 GMT
Actual measurements!
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Post by scpg02 on Aug 22, 2010 22:46:29 GMT
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Post by astroposer777 on Aug 22, 2010 22:47:23 GMT
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Post by scpg02 on Aug 22, 2010 22:48:29 GMT
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Post by nautonnier on Aug 22, 2010 23:27:53 GMT
icefisher"You went on to explain negative feedback as limiting the warming at the surface.
I pointed out if the negative feedback is stronger than the forcing its not feedback at all but instead an elemental forcing not included in the model. "That is an interesting point. Although in a chaotic system the response to an input can easily be significantly more than the size of the input. Like touching the hair trigger on a punt-gun But the next time that same input is made - nothing may happen. I am not sure that all this simplistic talk of 'feedback' makes a lot of sense in a chaotic system itself made up of many chaotic interacting subsystems some of which may be close to moving from their current attractor. It would probably be more correct to talk of system reaction - and even then it would need to have some kind of indication of the state(s) of the system(s) at the moment of the input.
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Post by icefisher on Aug 23, 2010 0:36:40 GMT
icefisher
"You went on to explain negative feedback as limiting the warming at the surface.
I pointed out if the negative feedback is stronger than the forcing its not feedback at all but instead an elemental forcing not included in the model. "
That is an interesting point. Although in a chaotic system the response to an input can easily be significantly more than the size of the input. Like touching the hair trigger on a punt-gun But the next time that same input is made - nothing may happen.
I am not sure that all this simplistic talk of 'feedback' makes a lot of sense in a chaotic system itself made up of many chaotic interacting subsystems some of which may be close to moving from their current attractor. It would probably be more correct to talk of system reaction - and even then it would need to have some kind of indication of the state(s) of the system(s) at the moment of the input.
The results of touching a trigger isn't feedback to the trigger alone it is feedback to the cocking of the gun delayed by the trigger mechanism. Accelerated melting of ice has to come from warmth, thus the melting of the ice can mediate the warmth but not overpower it because if it does then the melting is not coming from extra warmth. Likewise the feedback to the cocking of the punt gun can't be more than the forcing that cocked it. Its possible for the coolness of the arctic to be feedback just not feedback from extra surface warmth melting ice because there is none by what socold admitted was the best measure. That was my question to Socold, where did the CO2 forcing go during the summer. The decreasing ice mass in the arctic is apparently due to less freezing in the winter, perhaps less precipitation, maybe extra winter warmth (ocean currents perhaps). But if the extra warmth comes from the atmosphere CO2 why isn't it there in the summer busily warming the surface melting more ice? Socold produced a model run that does not fit what is happening. The model run shows warming year round in the arctic at all but the highest levels in the atmosphere with diminished warming in the summer suggesting feedback from accelerated melting of ice. That would be possibly feedback from ice melting in the presence of extra heat at the surface melting the ice. But that is apparently not what is happening. There is an important missing element to the models devising actual cooling of the arctic surface temperatures. p.s. Going a step further one has to ask how you get tropospheric warming from CO2 without at least some surface warming. That is a question that should be answered also because accelerated tropospheric warming has been postulated from the basic premise of surface warming. That further brings into question Socold's model run.
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Post by socold on Aug 23, 2010 1:15:36 GMT
Looks like it fits quite well to me. Simulated temperature response to sea ice loss: Observed arctic temperature changes: There are some clear similarities in pattern. There are observations of the arctic troposphere if you include reanalyses - just like how the graph you posted of arctic surface temperatures is from a reanalysis too. I disagree but mainly because I don't think feedback and forcing make sense here. At the very least I find it an unnecessary complication. This is actually a simple concept regarding the behavior of a warming arctic with respect to "where does the heat go". In summer a large part of the additional heat that would warm the air instead gets used in melting the ice, therefore leaving the air to only warm up a bit. Whereas in winter the additional heat can all go into warming the air, thereby warming it up a lot more than in summer. That's a pretty simple mechanism for why the winter surface temperature would be warming faster than the summer. It also suggests, and this is less intuitive, why in the summer the tropospheric trend may be higher than the surface. The implications of all this being quite significant as the sea ice during summer is depleting, so therefore it's role as a heat sink is diminishing.
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Post by magellan on Aug 23, 2010 2:10:41 GMT
Looks like it fits quite well to me. Simulated temperature response to sea ice loss: Observed arctic temperature changes: There are some clear similarities in pattern. There are observations of the arctic troposphere if you include reanalyses - just like how the graph you posted of arctic surface temperatures is from a reanalysis too. I disagree but mainly because I don't think feedback and forcing make sense here. At the very least I find it an unnecessary complication. This is actually a simple concept regarding the behavior of a warming arctic with respect to "where does the heat go". In summer a large part of the additional heat that would warm the air instead gets used in melting the ice, therefore leaving the air to only warm up a bit. Whereas in winter the additional heat can all go into warming the air, thereby warming it up a lot more than in summer. That's a pretty simple mechanism for why the winter surface temperature would be warming faster than the summer. It also suggests, and this is less intuitive, why in the summer the tropospheric trend may be higher than the surface. The implications of all this being quite significant as the sea ice during summer is depleting, so therefore it's role as a heat sink is diminishing. The implications of all this being quite significant as the sea ice during summer is depleting, so therefore it's role as a heat sink is diminishing. Purely speculative. www.frontier.iarc.uaf.edu/~igor/research/amplif/index.phpModerating role of arctic ice? . Perhaps the lack of polar amplification of global warming in SAT records is due to the moderating role of arctic ice? The ice-extent and fast ice thickness time series display a combination of decadal and multidecadal variability, with lower values prior to the 1920s, in the late 1930s-40s, and in recent decades, and higher values in the 1920s - early 1930s, and in the 1960-70s (Figure 3). This is consistent with the multi-year variability (LFO) evident in SAT records (Figure 1). Analysis of trends in these records shows that they are not statistically significant. Trends for recent decades seem to be larger but because of the fewer degrees of freedom in these shorter time records they are not statistically significant either. This is inconsistent with a hypothesis that sea ice has moderated arctic air temperatures in the last century, reducing atmospheric warming through ice melt. . . Conclusions
Arctic variability is dominated by multi-decadal fluctuations. Incomplete sampling of these fluctuations results in highly variable arctic surface-air temperature trends. Modulated by multi-decadal variability, SAT trends are often amplified relative to northern-hemispheric trends, but over the 125-year record we identify periods when arctic SAT trends were smaller or of opposite sign than northern-hemispheric trends. Arctic and northern-hemispheric air-temperature trends during the 20th century (when multi-decadal variablity had little net effect on computed trends) are similar, and do not support the predicted polar amplification of global warming. The possible moderating role of sea ice cannot be conclusively identified with existing data. Observed long-term trends in arctic air temperature and ice cover are actually smaller than expected, and may be indicative of complex positive and negative feedbacks in the arctic climate system. In summary, if we accept that long-term SAT trends are a reasonable measure of climate change, then we conclude that the data do not support the hypothesized polar amplification of global warming. Now ask socold why climate models could not reproduce Arctic warming and cooling pre-1970
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Post by icefisher on Aug 23, 2010 4:28:12 GMT
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Post by stranger on Aug 24, 2010 1:47:30 GMT
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Post by sigurdur on Aug 24, 2010 1:54:58 GMT
Does anyone else notice the spike in temps around day 320-340 in many years?
This is interesting, and one has to wonder what happens at that time of year in a lot of years that there is this dramitic spike. The spike would be well out of the normal error bars so has to be considered a real happening.
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Post by astroposer777 on Aug 24, 2010 2:32:51 GMT
I looked up acronyms and it could also stand for "Master of Arts in Theology-Nice and Tight-Feeding at Keyboard"
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Post by astroposer777 on Aug 24, 2010 3:32:54 GMT
Does anyone else notice the spike in temps around day 320-340 in many years? This is interesting, and one has to wonder what happens at that time of year in a lot of years that there is this dramitic spike. The spike would be well out of the normal error bars so has to be considered a real happening. What truly stands out is the fact that almost all of the spikes in temperature occur during periods when there would be little or no solar influence (polar night). I think that polar temperature fluctuations during late fall/winter/ early spring are almost entirely controlled by atmospheric pressure variations, which probably exhibit similar patterns at certain times of year more often than not. I think the scientific term for this is Arctic Amplification.
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