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Post by magellan on Feb 12, 2009 1:15:43 GMT
I didn't see icefisher use the word 'trend'. Did you? I saw him use the word 'dropped' and this seems to be,, entirely accurate.Ok fair enough - I assume it's entirely accurate, then, to say that temperatures have risen ~0.4 deg in the past 12 months. Though, of course, icefisher doesn't include the most recent months in his 'analysis', so I'm not sure what he claims is "entirely accurate". Point me to the data that indicates the oceans are gaining heatPoint me to where I said the oceans were gaining heat. What you still cannot grasp is the SST are not averaging upward, but downward.I can't grasp that fact because I'm not sure it's true. Certainly SSTs were lower in 2008 than they were in the previous 6 or 7 years but they were still warmer than they were in 1999 and 2000 and much warmer than any year prior to 1997. You are falling into the same trap that a number of sceptics fell into in 1999/2000. Following the 1997/98 El Nino many thought the 1999/2000 La Nina would herald the onset of a global cooling phase. In fact some leading sceptics such as Chip Knappenburger were prepared to place bets on a statistically significant cooling trend over the following decade. Chip K has since admitted he was wrong. The recent SSW (yes it was unusual) results in about a 4 week lag for tropospheric temps to respond, which means we should be seeing this in the coming week or so. In what way will the troposphere respond? Can you link to any literature which discusses SSW and the troposphere temp lag. I say there will be a dramatic cooling at the surface for the following ~2 months. What do you say? It depends what you mean by 'dramatic'. I think temperature anomalies will be a bit lower over the coming months but the year as a whole will be warmer than last year. OHC data has shown no increase after 2003. Frankly I don't care what Chip Knappenburger said 10 or 12 years ago. The oceans tell the real story, not the atmosphere. The reasons for that are glaringly apparent. Information on SSW (MMW) is available. I don't care to the work for you.
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Post by nautonnier on Feb 12, 2009 2:01:22 GMT
The recent SSW (yes it was unusual) results in about a 4 week lag for tropospheric temps to respond, which means we should be seeing this in the coming week or so. In what way will the troposphere respond? Can you link to any literature which discusses SSW and the troposphere temp lag. I say there will be a dramatic cooling at the surface for the following ~2 months. What do you say? It depends what you mean by 'dramatic'. I think temperature anomalies will be a bit lower over the coming months but the year as a whole will be warmer than last year. Not wanting to get involved in the - yes you did - no you didn't - but I had just read this .... What kind of sudden stratospheric warming does propagate to the troposphere?Extract from Abstract: A sudden stratospheric warming (SSW), a sudden breakdown of the stratospheric polar vortex, is caused by dynamical forcing of upward propagating planetary waves from the troposphere [Matsuno, 1971]. Recently, a growing body of evidence is accumulated for that a change in the stratospheric circulation affects the tropospheric circulation. The change in strength of the stratospheric polar vortex propagates into the troposphere within a few weeks and the influence of the stratospheric circulation on the troposphere persists up to two months [Baldwin and Dunkerton, 1999, 2001].I think that gives you sufficient reading and 'literature' on the subject.
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Post by icefisher on Feb 12, 2009 5:21:13 GMT
You are being impatient. If you look at Hadcrut, temps have been above average for 30 years with the exception of 2 years early on where the flux took it about a .03 of a degree below. And that was an "accelerated" warmingWe were discussing the SSW event (or I thought we were). Are you suggesting it will be 30 years before before the full effect of that becomes evident. Walterdnes in his post (see above) has suggested the upper stratosphere has already returned to near normal. If we have an "accelerated" cooling it should take another 10 to 20 years to drop below average, even though it is almost half way back already. We are not "half way back". Global temperatures to-day are higher than what they were 10 years ago when ENSO conditions were similar - but we were also approaching a solar maximum back then. So temperatures are still higher than they were at the last solar maximum. I can only think you are arriving at your figures by cherrypicking start and end dates . There is no cooling trend. Seems one should expect a little warming for a couple of years before it returns to its long sojourn back to normalcy.Why? The PDO is in a negative phase, we've had La Nina type conditions for ~18 months and we're in a deep solar minimum - why should there be warming? Already its dropped a quarter degree. No it hasn't. There is no data to support this. During the "accelerated" warming phase it took 12 years to do that before it dropped back again for 5 years. I'm not sure what this means. What took 12 years? So do you always just spout off about stuff without looking at any of the facts? Bottom line is I was reply to your post #9, you didn't address SSW until post #10 to a different poster. And in reply to some of your unsupported suppositions, you should not that one of those cooling retrogrades in the fourth year, (1982) of that warm period while solar activity was in the midst of a far above average maximum and while an El Nino was dominating the year cooled. Cycle 21, what we are talking about was one of the top 3 cycles in history. Our current minimum isn't even close to a top three record in depth, yet it is being suggested by you it is evidence of no cooling trend exists. Bottom line is the peak annual temperature was 1998 at a .546 degreesC positive anomaly. The most recent year to compare was 2008 at .325. Thats nearly a quarter degree. HadleyCrut is the source. What took 12 years was for the "accelerated" warming trend to breach the 1/4 mark. While this cooling trend hasn't done that yet it has gotten closer to it than it did during the first 11 years of the warming trend. Have fun splitting hairs but the fact is the facts do not support you.
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Post by icefisher on Feb 12, 2009 5:36:13 GMT
I can't grasp that fact because I'm not sure it's true. Certainly SSTs were lower in 2008 than they were in the previous 6 or 7 years but they were still warmer than they were in 1999 and 2000 and much warmer than any year prior to 1997. Any year? You mean any year since we had satellites measuring it. We have had almost 30 years of warming during that period. Its just plain ignorant to claim there is no cooling because 5 years after it started cooling it wasn't as cool as 12 years ago yet. Fact is the reversal of an "accelerated" warming trend should on average be back 10 years after 5 years. (5 years on each side of the curve) Saying we aren't cooler than 1997 simply isn't an argument because thats better than you would expect it to be on average when only natural forcings are at work.
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Post by glc on Feb 12, 2009 8:15:57 GMT
I think that gives you sufficient reading and 'literature' on the subject
Well that depends on what Magellan meant when he wrote this
"The recent SSW (yes it was unusual) results in about a 4 week lag for tropospheric temps to respond, which means we should be seeing this in the coming week or so."
In what way does he expect tropospheric temperatures to respond?
Icefisher:
Bottom line is the peak annual temperature was 1998 at a .546 degreesC positive anomaly. The most recent year to compare was 2008 at .325. Thats nearly a quarter degree. HadleyCrut is the source.
Ah - I see . So you are comparing the temperature anomaly for the year which had an unusually intense El Nino with a La Nina year. Why don't you compare 2008 with 1999 or 2000?
Its just plain ignorant to claim there is no cooling because 5 years after it started cooling it wasn't as cool as 12 years ago yet. Fact is the reversal of an "accelerated" warming trend should on average be back 10 years after 5 years. (5 years on each side of the curve)
You seem to be expecting some sort of symmetry about the 2003 point. I would have thought that would be dependant on a number of factors but, ok, have it your way. We'll just have to wait a few more years before we know whether or not 2003 really was a turning point, but rather than just comparing individual years either side of the 2003 maximum, I suggest you compare the average over a decade.
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Post by tallbloke on Feb 12, 2009 12:26:04 GMT
I didn't see icefisher use the word 'trend'. Did you? I saw him use the word 'dropped' and this seems to be,, entirely accurateJust to return t this point. Whether he was aware if it or not, I think icefisher was actually referring to the trend. His plot shows a trend line and it is the trend line which appears to fall ~0.25 deg (from start to end). You're getting confused glc, it was I who posted the woodfortees graph with the trendline which showed that icefisher's assertion that the temperature had dropped 0.25C was correct. You still haven't explained how you get jan2005-dec2008 to be "less than three years". Nor have you explained how the graph doesn't include "recent months". Given that the data is the latest available this is unfair surely? Paul at woodfortrees.org will be updating wti as soon as the Jan data is in for all four indices. Shall we revisit it then and see how much your niggle over 1 month's data matters?
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Post by glc on Feb 12, 2009 13:04:56 GMT
You're getting confused glc, it was I who posted the woodfortees graph with the trendline which showed that icefisher's assertion that the temperature had dropped 0.25C was correct
Actually he now seems to be referring to the Hadley record, i. he's cherry picked 1998 (an intense El Nino) and compared it with 2008 a La Nina year. He chose not to compare 2008 with other La Nina years such as 1999 or 2000. I can't think why.
You still haven't explained how you get jan2005-dec2008 to be "less than three years".
Ok - less than 4 years. The same point applies.
Nor have you explained how the graph doesn't include "recent months".
This may depend on what smoothing - if any - is used and where the Jan data point lines up. I would have expected the Dec data data point (end of year) to line up with the year label and the Jan data point (denoting end or posibly mid Jan) to be further along the axis. But it really doesn't matter because the plot is totally irrelevant. It's too short a timescale. Why not plot Jan 2008 to Jan 2009
Shall we revisit it then and see how much your niggle over 1 month's data matters?
None of it matters on that time scale because you're simply using a 4 year trend of which the last year is dominated by a La Nina, so naturally the La Nina will dominate the trend. I suggest we revisit it in 2 or 3 years. If you like 4 year trends, though, try plotting 1998-2001. It was in 1999/2000 that a lot of people were saying exactly what you're saying now for exactly the same reason as you, i.e. they focused on short term trends.
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Post by magellan on Feb 12, 2009 14:17:33 GMT
You're getting confused glc, it was I who posted the woodfortees graph with the trendline which showed that icefisher's assertion that the temperature had dropped 0.25C was correctActually he now seems to be referring to the Hadley record, i. he's cherry picked 1998 (an intense El Nino) and compared it with 2008 a La Nina year. He chose not to compare 2008 with other La Nina years such as 1999 or 2000. I can't think why. You still haven't explained how you get jan2005-dec2008 to be "less than three years".Ok - less than 4 years. The same point applies. Nor have you explained how the graph doesn't include "recent months".This may depend on what smoothing - if any - is used and where the Jan data point lines up. I would have expected the Dec data data point (end of year) to line up with the year label and the Jan data point (denoting end or posibly mid Jan) to be further along the axis. But it really doesn't matter because the plot is totally irrelevant. It's too short a timescale. Why not plot Jan 2008 to Jan 2009 Shall we revisit it then and see how much your niggle over 1 month's data matters? None of it matters on that time scale because you're simply using a 4 year trend of which the last year is dominated by a La Nina, so naturally the La Nina will dominate the trend. I suggest we revisit it in 2 or 3 years. If you like 4 year trends, though, try plotting 1998-2001. It was in 1999/2000 that a lot of people were saying exactly what you're saying now for exactly the same reason as you, i.e. they focused on short term trends. None of it matters on that time scale because you're simply using a 4 year trend of which the last year is dominated by a La Nina, so naturally the La Nina will dominate the trend. I suggest we revisit it in 2 or 3 years. If you like 4 year trends, though, try plotting 1998-2001. It was in 1999/2000 that a lot of people were saying exactly what you're saying now for exactly the same reason as you, i.e. they focused on short term trends. The heat is still not there regardless of what you say. A whole ten years was used by Hansen (IPCC AR4) to conclude it was "proof" of CO2 AGW. We are now going on seven years with no added heat to the system. That may be "short term", yet there is a reason for every weather/climate event; things don't "just happen". Also, despite NASA verifying the existence of PDO shift in April and then again in December last year, it sails right over your head. You must therefore place a lot of confidence in the radiative forcing part of AGW, however it will fail because it has never been proved to work as advertised in the past, so why will it now? What else other than the sun can warm the oceans? climatesci.org/2009/02/09/update-on-a-comparison-of-upper-ocean-heat-content-changes-with-the-giss-model-predictions/
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Post by heatsink on Feb 12, 2009 17:16:19 GMT
In terms of climate, I have to agree with glc. In order to see a reversal of the 20th century warming trend, we would need a trend of at least a few years of climate data smoothed over five years. Other wise the change could be a blip on the chart when we look back 50 years from now.
When looking at the 400 years of warming since the LIA, we need, at least, 20 years of tend data smoothed over a 10 year time scale.
Another way to look at the data could be to wait for three full ENSO positive and negative cycles before we can declare a change in the climate direction.
In terms of AGW, I think the shorter weather statistics are justified. Human CO2 emissions have only been substantial for the past 50 years. The AGW proponents think they can prove their case with this short data set. This time includes a rare solar grand maximum. If we select 10 years of this data, that come to over 20% of their data set. If we select 5 years, it come to 10%. Both are a significantly large percent of the time in question.
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Post by socold on Feb 12, 2009 18:52:49 GMT
On the otherhand a 10 year period is far more succeptible to the pattern of ENSO events than say a 20 year period.
If your 10 year period starts with a strong El Nino and ends with a strong La Nina with ENSO neutral inbetween, then that 10 year trend will be subject to a significant downward bias having nothing to do with the longterm trend.
So when you observe a downward trend in that 10 year period, is that because the longterm trend has reversed? Or because of the pattern of ENSO over that period?
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Post by icefisher on Feb 13, 2009 2:12:06 GMT
I think that gives you sufficient reading and 'literature' on the subjectIcefisher: Bottom line is the peak annual temperature was 1998 at a .546 degreesC positive anomaly. The most recent year to compare was 2008 at .325. Thats nearly a quarter degree. HadleyCrut is the source.Ah - I see . So you are comparing the temperature anomaly for the year which had an unusually intense El Nino with a La Nina year. Why don't you compare 2008 with 1999 or 2000? Why in the world would I do that? I made the mirror image comparison for the warming trend. Bottom line is what it explains is there is more than CO2, solar maxes, and El Nino/La Nina's affecting the temperature record. Perhaps its just random error in the sampling program, but its there as a natural fluctuation. You claim there is no cooling trend ostensibly because 3 years of cooling and 11 years of no warming isn't enough for you. But you are perfectly happy to use the opposite of that logic to destroy something you claim doesn't exist. It doesn't make sense destroying a cooling trend with something you believe to not represent a new trend or an adequate continuation of an existing trend. You seem to be expecting some sort of symmetry about the 2003 point. No I don't expect symmetry. There is some degree of symmetry to the start of the previous warming cycle. . . .and as long as that continues there is no evidence that there isn't cooling going on. I would have thought that would be dependant on a number of factors but, ok, have it your way. We'll just have to wait a few more years before we know whether or not 2003 really was a turning point, but rather than just comparing individual years either side of the 2003 maximum, I suggest you compare the average over a decade. What I find remarkable is in the midst of so much doom saying we found an 11 year period with no new record warm year. We haven't seen anything like that for 30 years. The closest we came was a single 5 year stretch that included the Pinotubo eruption. Excluding that known cause, the previous record drought in the hockey stick era was 4 years during the cycle 22 minimum. If we don't have a record warm year this year we will have tripled that. What kind of multiple are you looking for GLC?
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Post by nautonnier on Feb 13, 2009 2:17:21 GMT
On the otherhand a 10 year period is far more succeptible to the pattern of ENSO events than say a 20 year period. If your 10 year period starts with a strong El Nino and ends with a strong La Nina with ENSO neutral inbetween, then that 10 year trend will be subject to a significant downward bias having nothing to do with the longterm trend. So when you observe a downward trend in that 10 year period, is that because the longterm trend has reversed? Or because of the pattern of ENSO over that period? "If your 10 year period starts with a strong El Nino and ends with a strong La Nina with ENSO neutral inbetween, then that 10 year trend will be subject to a significant downward bias having nothing to do with the longterm trend."Or to slightly rephrase that If your 10 year period starts with the Pacific SST hot and ends with the Pacific SST very cold with ENSO neutral inbetween, then that 10 year trend will be subject to a significant downward bias having nothing to do with the longterm trend. Well what you have seen in that period is the ocean getting colder this is not a downward bias its a huge loss of heat.
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Post by icefisher on Feb 13, 2009 2:32:57 GMT
Actually he now seems to be referring to the Hadley record, i. he's cherry picked 1998 (an intense El Nino) and compared it with 2008 a La Nina year. He chose not to compare 2008 with other La Nina years such as 1999 or 2000. I can't think why. I cherry picked nothing GLC. I took the most recent three years of cooling (and your prognostications on the implications of a possible fourth year with some warming); and compared that to the first 3 years of the warming trend in 1978 heralding the "accelerated" warm phase. . . .it was followed by two years of cooling during an El Nino that started in the last year of a very high solar max. Its a mirror image except the introduction of that warm phase was weaker than the past 3 year change.
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Post by poitsplace on Feb 13, 2009 6:40:13 GMT
On the otherhand a 10 year period is far more succeptible to the pattern of ENSO events than say a 20 year period. If your 10 year period starts with a strong El Nino and ends with a strong La Nina with ENSO neutral inbetween, then that 10 year trend will be subject to a significant downward bias having nothing to do with the longterm trend. So when you observe a downward trend in that 10 year period, is that because the longterm trend has reversed? Or because of the pattern of ENSO over that period? So if we had a 30 year stretch starting out with La Nina conditions and a couple volcanic eruptions and ending in El Ninos and no eruptions (which is actually a little bit unusual for such a long period of time)...we would expect warming and not think anything of it? Gee, I wonder if such conditions have ever existed...hmmmm
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Post by glc on Feb 13, 2009 9:43:37 GMT
What I find remarkable is in the midst of so much doom saying we found an 11 year period with no new record warm year. We haven't seen anything like that for 30 years
This has more to do with the magnitude of the warming during the 1998 El Nino year. The global temp anomaly for 1998 far exceeded anything that had gone before. It was a bit like the Bob Beamon long jump record in 1968 which beat the previous world record by ~2 feet and wasn't surpassed until the 1990s. But it would be nonsense to suggest that later long jumpers such as Carl Lewis were not as good as Beamon simply because of this one jump.
I cherry picked nothing GLC.
I took the most recent three years of cooling (and your prognostications on the implications of a possible fourth year with some warming);
Ok - what about 1998-2000? A much greater cooling trend which was interpreted at the time - mistakenly as it happens - that warming had stopped and cooling was now underway. Funnily enough - exactly the same interpretation you're making now.
and compared that to the first 3 years of the warming trend in 1978 heralding the "accelerated" warm phase. . . .it was followed by two years of cooling during an El Nino that started in the last year of a very high solar max.
....and a volcanic eruption.
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