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Composer99 at 03:16 AM on 20 October 2012Salby's ratio
Salby's graph appears to rely on a misrepresentation of IPCC/mainstream climatology, one which I have seen in many a comment thread. This misrepresentation relies on the assumption that the IPCC/mainstream climatologists believe global climate or temperature depends solely on CO2. As Chapter 2 (PDF) of the >IPCC AR4 (Working Group 1) shows, this misrepresentation is clearly false. -
markx at 03:02 AM on 20 October 2012Nuccitelli et al. (2012) Show that Global Warming Continues
Thanks, Mark R. Correct me if I'm wrong, but aren't the "Net Heat Content" measures we are discussing here derived from actual measurements of ocean temperature? If so, is there any possibility that measurements taken prior to the deployment of the 3,200 Argo floats may not have been accurate enough for us to be sure we have recorded a 0.09 C increase in temperature worldwide and across a 2000 metre depth? Or was this figure derived from modeling the calculated increase in energy content? "...We have estimated an increase of 24x1022 J representing a volume mean warming of 0.09°C of the 0-2000m layer of the World Ocean...." (Ref Levitus etal 2012) -
Doug Bostrom at 02:54 AM on 20 October 2012The Future We All Want
In addition to Fabiano's generous offer of advice, folks who like to tinker and are interested in solar hot water systems might want to visit the website Build It Solar which has a marvelous compendium of solar energy information for DIY types. One key tip: if you're building a home or remodeling, take the opportunity to include a path for plumbing and wiring to the roof. Make it easier to install a system for yourself or somebody else in the future. This seemingly minor matter is a large driver of installation cost, often the largest. -
Bob Lacatena at 02:33 AM on 20 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
Kevin C, I disagree. Dale's "question" amounts to an implication of the following: 1) Grudging acceptance that yes, there would be a record low this year, but... 2) We don't know how much the storm contributed to the low. 3) The storm therefore could be responsible for all ice melt more than a smidgeon over the record. 4) Therefore it's not really that big a deal, and we can delay a little longer. Outside of this context, the question of "how much did the storm contribute to the record" is really of no interest at all (at least to me). It was a reasonably rare storm, so how soon will it happen again? If it doesn't, then four years from now will you say "remember that storm back in 2012?" or will you say "oh, yeah, that, I'd forgotten." It is only of interest if changes in the Arctic make it not-so-rare anymore, in which case that is a big story in itself, that Arctic melt has generated an unexpected positive feedback in new weather systems that exacerbate the melt. It was also only one factor, and the main factors (serious melt in spite of otherwise mild weather) this year, as well as the main factor (global warming) that is demonstrated by the multi-year trend, are what are of interest, not singular events that affect the details. So... to me, the question and the lengthy debate are all designed to put doubt into people's minds as to whether or not this year's Arctic low means anything in terms of global warming in general and specifically the dangers of the future pace of Arctic summer ice melt. That's denial, plain and simple, and it angers me. -
Salby's ratio
Chris G - WoodForTrees has "Scale" and "Offset" parameters that can be adjusted. Just make sure your changes are to the correct CO2/temperature scales, unlike Salby's. -
markx at 01:25 AM on 20 October 2012Salby's ratio
The obvious lesson is with use of the correct scales any two near linear curves can be made to match,or to not match. -
What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
The storm was not the sole cause of the observed low area, but rather one factor involved. Storms like that are part of the natural variability (+/-) of Arctic ice extent. It was also not a sufficient cause for this years area, as seen by previous storms of similar magnitude not driving ice area to record lows. The storm was a contributing but not sufficient cause, one that only induced some variability over a multi-year trend of low ice volume due to another causal factor entirely - warming. In fact, if 2012 had the same weather factors as 2007, I expect the ice area minima would have been much much lower - this years weather was nowhere near as strong an influence on variability as 2007's. What dana1981 and Albatross have shown is that the 05 August 2012 storm cannot (by itself) be blamed for the low 2012 area, part of denying (as many 'skeptics' have attempted) the issue of declining total ice levels driven by global warming. Pointing to the storm and misattributing low Arctic extent solely to that variability factor is a "Look, squirrel" red herring. -
Chris G at 01:07 AM on 20 October 2012Salby's ratio
Nicely done, Tom. Trivial: "Off these..." Shoyemore, thanks for that link. Now I'm wishing WoodForTrees had a ln ratio function that could be applied. Suppose not hard to do with the graph data itself. -
Fabiano at 01:03 AM on 20 October 2012The Future We All Want
Hi Doug! Thank you for your post! There are different types of water heaters. The best ones are made of durable material and the energy consumption for their production is low. They work very well and there´s little impact on the environment. You can make your own one as I did at home. If you´re interested please let me know so that I can give you some tips. My email is: fabiano.scarpa@inpe.br Cheers, Fabiano. -
DSL at 00:14 AM on 20 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
My two cents on measuring storm impact. I think the first thing to do is eschew extent as the proper measure of the storm's impact. Extent/concentration is important in predicting potential melt conditions, but it's not a good metric for actual melt. I know using area has some issues (though the melt pond issue should be much less of an issue during the freeze season), and PIOMAS, while recently confirmed by Cryosat, has fairly large error bars. However, area and volume are still the more direct measures of melt, and the dailies are more problematic than the trends. Extent is highly variable and obviously especially susceptible to wind and current. It's the one place where "skeptics" don't have to work so hard at indulging in a bowl of cherries. -
DaneelOlivaw at 22:24 PM on 19 October 2012Salby's ratio
I've also seen some rescaling tricks while looking around near denialist blogs. Hey, look! There's no relationship between CO2 and temperature:
Oh, wait, it turns out there actually is one:
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chriskoz at 22:10 PM on 19 October 2012Salby's ratio
Nice debunking, Tom. Good to see you back and kicking on SkS after a longish break... The title would be better "Salsby's rescaling", which more adequately describes the misleading distortion by the subject, a central point of the article. BTW, Salsby is not the first one to employ the "graph rescaling trick". I've seen very similar trick on lord Monckton's slides. Unfortunately, I don't remember where Monckton presented it. Quite possibly, he did it on his visit to Australia, in which case Monckton is likely Salsby's inspiration. I dare to add that I share opinions that Monckton's willful deceptions can be considered criminal acts. So can be Salsby, Monckton's follower. It's not our duty to setup the trials here but our very duty is to debunk harmful deceptions. Well done. -
Kevin C at 21:29 PM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
A few possible lines. I don't have time to follow these up: 1. Obviously projecting sea ice anomalies forward across the storm is worth trying. The confounding factor is that the annual cycle seems to have been changing over recent years. This can be tested for the other storms as well. 2. While IIRC air temperatures were low this year, SSTs were high. If ice melt for other high SST years can be examined, then an attempt to determine the impact could be made. 3. Ice thickness, of course, which confounds any comparison with past years. While clearly a factor, I don't see a good way to test how big. 4. Other factors mentioned at Neven's: changing ocean circulation, influx of fresh water, low snow cover. First step: eyeballing the CT anomaly tape suggests ~300k drop over a month around the storm, but that ignores any decline which would be happening due to the new seasonal cycle. 2011 was also declining over the same period, so that's more likely an overestimate. Tamino has done something on anomalies against time varying baseline, that would be the next step. -
Kevin C at 20:51 PM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
Looking at this discussion, there are a couple of ionteresting things going on. Firstly, there has been a re-framing of what the article is about. The article was a response to various claims that the arctic minimum was not evidence for a decline in Arctic ice (ideally some more of these could be cited). The messaging was often subtle and implicit, along the lines: 'Declining ice means new records, this record was a fluke, therefore there is no evidence for a decline'. Reading various news site comment threads you can see that the hoi polloi have taken the implied argument and run with it. The article was not directly addressing Dale's more neuanced position, although it contains work which is relevant to it. However the discussion has continued as if it did. You could call that a thread hijack (although I don't claim it was deliberate or even attribute it to a single poster or post, it happens unintentionally all the time). I do however think that one contributory factor was Dale's @5. Dale, I presume you would recognize that there is a well-used debating trick of asking an unanswerable question and then drawing conclusions (or inviting the audience to draw conclusions) from the fact the question has no answer. However, in context, the question could equally well be legitimate. None of us can decide without access to Dale's thoughts. Now an aside about skepticism. I've been thinking about whether real skeptic and fake skeptic arguments can be distinguished on the basis of form alone - whether fake skepticism has a fingerprint which can be detected without investigating the content of the argument. Here's the sort of thing I'd be looking for as a first guess, but it needs study (e.g. in climate forums):- Fake skeptics will start from a piece of evidence which supports their position, and avoid encountering additional evidence in case it is inconvenient to their position.
- Real skeptics will be looking for additional evidence to test their views against.
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bratisla at 20:07 PM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
correction : "the added loss by the storm" instead of "the loss" in the last paragraph. I substracted 2012's figure from the mean of other years for the corresponding days, and then I widly integrated. All of that with my eyes as a calculator, so don't put too much weight on this estimate :] -
bratisla at 20:05 PM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
Thanks Bob Loblaw, you throroughly answered my question then :) I didn't think about checking Neven's posts on skepticalscience, hence my miss. The difference of rate of loss between the storm day in 2012 and the other years does not seem that staggering. Therefore, I have difficulties with the NASA loss numbers due to storm indicated by Dale. So I searched on the Internet, and after a few tries making me land in Watts's universe, I found the following : http://earthobservatory.nasa.gov/IOTD/view.php?id=79256 where they say that August sea ice loss rates were enhanced by the storm, but no quantitative indication of the storm effect on the total sea ice minimum. From a naive point of view, and using Bob's graphs, I would say that the loss was in the 50-100 000 km² range, but not 750 000 km². I'm terribly sorry to disturb everyone here, but could someone please share with me a link from NASA/NOAA with the 750 000 km² number ? -
MarkR at 18:37 PM on 19 October 2012Nuccitelli et al. (2012) Show that Global Warming Continues
Hi markx @ #60. You can see the error bars on Levitus et al pentadal estimates in their Figure 1. I'm not sure of the exact details, but those error bars are believable. We can estimate the rough size from basic statistics of Normal distributions. Typically the errors get smaller at a rate of the square root of the number of measurements. For 5 years you have about 180 measurements from each ARGO float, and with 3,200 floats that means that to reach 0.01 C uncertainty in the overall estimate you need to have each ARGO float measuring to within +-7.5 C. This isn't exactly how the measurements are done afaik, and it's actually more complex than that once you include other features, but it does indicate that the size of the change you're considering should be detectable and it makes the Levitus error bars credible. But it should be remembered that this is different from the radiative forcing values calculated, since they look at trends in the data. With enough data, the error in a trend can be smaller than you'd expect from the original errors. -
shoyemore at 18:03 PM on 19 October 2012Salby's ratio
Some supplementary information - Professor John Nielson-Gammon does a nice little "smell test" here to see if temperature rise since 1979 is within the ball-park of what would be expected from CO2. Carbon Dioxide and Climate -
amyjoy at 17:48 PM on 19 October 2012Most coral reefs are at risk unless climate change is drastically limited
This is a very interesting post and goes back to what I was taught in Oceanography and Marine Biology. This post is completely true and it is scary how we are potentially going to lose our corals. Unfortunately a lot of people see the best solution for climate change to be geo-engineering. There are so many feedback mechanisms to consider and most geo-engineering 'solutions' have negative affects somewhere down the line. For example: many people want to use the ocean to take up more CO2 and take it out the atmosphere (by Fe fertilisation) and an increased uptake of CO2 by the oceans will have large negative effects on the coral as this will create more ocean acidification. Simply the best solution is mitigation; decrease CO2 emissions. -
Doug Hutcheson at 16:11 PM on 19 October 2012Salby's ratio
To misquote a saying from my youth: "Graphs and statistics are like a bikini: what they show is revealing, but what they hide is vital". Mr. Salby may be more crafty than careless. I think his rescaled bikini might have just given him a wedgie. -
YubeDude at 15:54 PM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
54 It is just as likely, if not more so, that the large margin of ice loss compared to the previous record was marginally helped by a cyclone that was significantly amplified in power by the vast amount of ice loss in the ocean where it spawned and then spun to full power. Who begat who? I do think that objectivity is compromised if a cyclone is labeled as a storm when all the metrics show a low system existed that can only be described as a cyclone (963mb). Choosing not to call it a cyclone only opens the door for contrarians to ask: why is it being low-balled, to suggest that something is being hidden and then to ask for what purpose are they suggesting this was not a cyclone of historic proportions? Tell them how big it was, mention how powerful it was, and add that the ice loss was on a trajectory for a new low before the cyclone helped it along. It's not the record that is the big news, it is the cycle of loss that is showing no signs of abating. -
LRC1962 at 15:47 PM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
@Dale, The proof I believe can be found in the ice loss charts themselves. Best if you look at all the different charts. If the August storm was indeed a prime mover of ice loss then there should have been a dramatic change in the slope of the losses over an extended period or if not that a near vertical drop at that point. All charts do show a dip, but if you compared the slope pre storm to the slope post storm the general slope of losses did not change that much, nor was there a vertical drop. Certainly it did more damage to the ice then already there, but the end result I believe would have been just about the same. The argument that it was following the same trend as 2007 at that point is also very incorrect. It just happened that the 2 years matched at that point. The truth of the situation was that the starting point of this years melt was far higher then in 2007 so that the slope 2012 was on was far steeper then in 2007, and just continued on that path. The only way 2012 before the storm could have avoided smashing the records was to have all of Aug and Sept to be very cold, cloudy, calm conditions. -
DSL at 15:09 PM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
Let's see what happened to volume. The following is a graph of 15-day linear trends starting on July 15th. The dates on the graph are the last day of the 15-day base period. There is indeed a dip where the storm occurs. There is indeed a recovery. Must have been a storm at the beginning of August in 2011, too, 'cause there's a dip there, too. Just checked. Nope.
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Dale at 14:26 PM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
Dana @50 Clarification: it's the qualification "by such a large margin". -
Jim Eager at 14:08 PM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
And you forget, Dale, that average ice age, and therefore ice thickness and strength, was much lower going into this summer than in previous years with storm events, making the ice far more susceptible to being broken up by a storm of similar magnitude. The proximate cause of this year's dramatic breakup and subsequent melt out may have been the storm, but the ultimate cause was the multi year decline in ice thickness due to the increased warming in the Arctic. -
Treesong2 at 13:53 PM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
Dale's 'Look! A monkey!' tactics have been thoroughly demolished but I'd like to throw one more rock. Hope I didn't miss something already said. The effect of the storm was to smash up weak ice and leave a greater proportion of strong multiyear ice in what was left. So even if the storm were replaced with Dale's 'normal', is it not likely that melting, having more weak ice to work on, would have proceeded faster and longer than it did in reality, thus significantly or even mostly wiping out the differential effect of the storm? -
DSL at 13:39 PM on 19 October 2012Salby's ratio
No excuses. Just a straightforward excursion into ethical la-la land. It remains to be seen whether Salby can be held accountable for it. Yet another test case for the proposition that we're heading deeper into the condition of postmodernity. -
Doug Hutcheson at 13:25 PM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
Dale @ 47It is not unreasonable to propose that the Arctic storm was the cause of "such a large margin".
Equally, it is not unreasonable to propose that the margin would have been larger if the weather had been different. It is playing games to argue for one outcome or the other. Only if you can stipulate what the weather would have been like, in response to the factors that caused the storm, can you stipulate what the result might have been. The storm had a cause before the event, so you must stipulate what would have happened if not the storm. Clearly, it would not have been business as usual, so just excising the storm without replacing it with effects that caused the storm is hand waving. -
dana1981 at 13:16 PM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
Dale @47 - the part of the post which you are nitpicking says"Can this single storm really be responsible for breaking the previous Arctic sea ice record by such a large margin? The short answer is no."
That is correct. By itself the Arctic storm was not responsible for 760,000 km2 of sea ice loss. The storm certainly played a role, but for all the reasons we discussed, the storm is not responsible for breaking the previous record. -
Doug Hutcheson at 13:11 PM on 19 October 2012It hasn't warmed since 1998
Rosco, that is news to me. Can you provide a link to their research that says "that there has been no warming for the past 15 years"? It must be powerful stuff, to overturn the laws of physics and the metrics of ocean heat content. -
YubeDude at 12:46 PM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
I missed something from 47# The storm was characterized as "an Arctic cyclone" yet reading the article I see no mention of this label. Also it appears that little credit (other than where the article talks about fetch and wave action) is given by Dale to the strongest action responsible for the break up. surface waves. It is only because of the loss of ice that this fetch is created and it is only over a large fetch that wave and swell activity can reach a potential to break apart thinner sections of ice. The storms potential only exist because of the open water after the extensive loss of ice. It's not the wind on the ice, it's the wind on the water that creates a sea surface that will impact the ice. Wind driven ice is proportionally small when compared to the winds effect on sea surface and those effects on the ice mass If a mod wants to consolidate this into my post @48...? -
Doug Hutcheson at 12:35 PM on 19 October 2012The Future We All Want
Fabiano, thanks for the link to that pdf. I am reading it with interest. Here, in Queensland, solar energy systems for hot water and electricity enjoy government subsidies of various types. I am in favour of both uses of solar energy, but my budget does not yet stretch far enough to be able to afford the initial capital outlay, even though there is a long term payoff. If/when the carbon cost of electricity and gas are added to their consumption cost, I expect the equation to become a no-brainer. From a sustainability viewpoint, there must be embodied carbon costs and the consumption of non-renewables (such as metals and rare minerals) in supplying conventional water heaters and in solar systems, but I do not know what they are. If solar construction causes more damage to the environment than conventional, it would not be such a good idea. -
YubeDude at 12:06 PM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
46 post to try and clear the air, then the 47th post did a reasonable job of synopsis only to turn and throw another log on the fire of rhetorical excess by anchoring to the idea of storm=cause of large margin; not partial cause or marginal cause but rather "the" cause. A few good analogies have been used, here is mine. A cold and fat homeless guy meets a girl, ask for a kiss, she says no. Next day same guy sees the same girl only this time he has shaved, again she says no. Next day he asks again only this time he is wearing a clean shirt, same answer. This goes on for so long that finally he has warmed up, lost weight and is now dressed to the nines, he is funny with wonderfully engaging banter, he has an expensive haircut, nice watch, is very polite and respectful, only this time he has splashed on some Stetson. She has been won over and now gives him the kiss. Proportionally speaking, how much credit goes to the cologne? It appears that some want to assign an undue amount of credit to a storm that undoubtedly played a role in this seasons numbers but only after enormous ground work had been laid. I am interested in the question someone raised that posited, maybe the storm was as powerful as it was due to the extensive ice loss; ice loss driving the storm more than storm driving the ice loss. -
Dale at 11:27 AM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
I just want to point out, that only Dana @38 has attempted to answer my question. Thank you Dana. Q. If the storm had not have occurred, would the minimum ice extent have been the same? A. I think it's accurate to say that 2012 wouldn't have broken the record by as much if not for the storm. THUS: The statement in the article that the Arctic storm was NOT responsible for "such a large margin" isn't entirely right. Regardless of all other factors, which are conditions on the long term trend, the 2012 minimum ice extent is so bad because an Arctic cyclone ripped up a huge section of ice, pushed it into warmer waters and caused it to melt a lot earlier than it would have (thus impacting other factors in the Arctic such as albedo, ice structure stability, etc etc). It is not unreasonable to propose that the Arctic storm was the cause of "such a large margin". -
markx at 10:38 AM on 19 October 2012Nuccitelli et al. (2012) Show that Global Warming Continues
Given that the world wide ocean temperature from 0 to 700 metres has risen a measured 0.18 degrees C in 55 years, and the world wide ocean temperature from 0 to 2000 metres has risen 0.09 degrees C in that time period: I ask; 1. How much has the 700 to 2000 metre temperature increased in that time? 2. How confident are we in the accuracy of these measurements? Especially going back 55 years, before the time of Argo buoys, when it was mainly buckets and ropes? (Ref Levitus etal 2012) -
Philippe Chantreau at 10:21 AM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
"NASA estimated from satellite pictures the extent of storm damage to be around 500,000 km^2. They noted large chunks of ice broken off the main pack and pushed southwards towards warmer waters where they would melt much faster." And what exactly made the ice so susceptible to be broken off and carried away? Your questgion is still a rethorical one, of no real interest. Here is another question of that kind: NASA said 500.000 sq.km eh? If that storm would have happened at the same time of the year to the ice pack of 15 years ago, how many sq. km would have been carried away? What that storm reveals is not that one can quibble over a weather event to argue about how badly a record low was broken (although it did that too). It reveals that summer Arctic sea ice shows signs of being moribund. No rethoric can diminish that fact. -
Bob Loblaw at 10:02 AM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
Dale: Do you understand the link between the graph I have provided and the graphs that are in the main post by Dana and Albatross? Specifically, their figure 2? My graph is simple the slope of their graph, which means that their graph is the integral of mine - or sums, if you prefer. You don't have to do the sums to compare the average melt rates: that's in figure 2, which clearly shows that 2012 was in substantial decline compared to previous years long before the August storm. The steep slope in figure 2 is not the result of the storm, as was pointed out in the post. You are utterly wrong in using your eyecrometer on my graph to conclude that 2012 was is not abnormal in terms of ice loss. Yes, picking 2007 weather is a cherry pick, just as picking "normal" to replace the August 2012 storm is a cherry pick. You don't feel I'm justified in my cherry pick, yet you still haven't justified yours. If the "comparison should be done with similar weather", then you can't remove the storm and replace it with dissimilar weather ("normal"), either. Once again, you are one-sided: you are only willing to consider cases where your hypothetical "different weather" is limited to "weather that reduces ice loss". You are still assuming your conclusion. Your replacement of the storm with weather conditions from 2012 is not reasonable, because if the storm were somehow magically prevented then the rest of the summer's weather would not have been the same. The energy and dynamics would have to go through a significant shift in the period following the storm/not storm, to compensate for the changes in energy that "removing" the storm would have. You can't tell if the rest of the summer would have had more, less, or the same amount of ice loss without a lot more detailed analysis than your hand-waving. You need to include an analysis of everything else that would have changed after the time of the storm, presuming that the storm didn't happen. Unfortunately, your mind-set won't let that happen, probably because to consider that would force you to reconsider your conclusion. You will only consider possibilities that move one way: to reinforce your preconceptions. -
Neven at 09:56 AM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
the 2012 summer was pretty ordinary, not conducive for high melt like 2007, and not conducive for slow melt I think that's wrong. In the weeks preceding the storm weather conditions were very conducive for slow melt. The same conditions slowed the melt in 2010 and 2011, but they didn't this time. Just read the intros of the ASI updates on the Arctic Sea Ice blog for a chronology, especially this one. The 2012 melting season was the melting season that definitely confirmed that the ice is thin. PIOMAS was already telling us that for quite some time, but that's a model so we couldn't be sure. Sea ice behaviour at the end of the 2011 melting season already raised the veil a bit, but what happened this season is very strong evidence, backed up by satellite observations (CryoSat-2 and SMOS). Would the margin between this year's record and that from 2007 (perfect storm) be as big if the ice hadn't been as thin? That's the question. The pertinent question relating to the big summer storm is this: Will we see more big summer storms as the thin ice retreats earlier so that the waters warm up more? Let's hope not. Very good post by the way, Albatross and Dana. Thanks for digging up all that info on previous storms. I will re-post on the ASI blog. -
Rosco Bell at 09:13 AM on 19 October 2012It hasn't warmed since 1998
Britain's Met Office’s Hadley Centre is said to be reporting that there has been no warming for the past 15 years. What do you make of this?Moderator Response: That "saying" is incorrect. See the Skeptical Science rebuttal. -
Dale at 09:13 AM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
Bob @37 A comment on your graph: it shows the red line moving up and down in the range of years. There's some bad melt days, and some not so bad. That looks fairly common across all years. I'm not doing the sums to see if the average daily melt is worse than the average of all other days, but I would not say it's abnormal. If it were, then the red line would stay on the high melt level all year. As for choosing 2007 weather conditions to replace the storm, that's cherry-picking. You're cherry-picking conditions from a bad weather year to slot into an average weather year. Comparison should be done with similar weather, not extreme weather. Like I can't say definitely that if the storm had not have occurred the weather would have been the same as it had been, you cannot say definitely the weather would be like 2007. The difference is, at least my replacement with weather conditions from 2012 is reasonable. DSL @39/40 NASA estimated from satellite pictures the extent of storm damage to be around 500,000 km^2. They noted large chunks of ice broken off the main pack and pushed southwards towards warmer waters where they would melt much faster. Jim @41 You forget that the article lists other storms of similar size and intensity right from the beginning of the satellite era, and no conclusion of increasing frequency or intensity of storms over time can be made. -
Rob Honeycutt at 09:12 AM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
My own inclination is to believe that the storm this summer only acted to reveal exactly how weak the remaining ice is, rather than the other way around. In this Dr David Barber lecture he discusses his trip on the ice breaker Amundsen where they found the quality of the ice to be substantially degraded in ways that were not being picked up by satellite imaging. I believe the Arctic ice sheet is about to start a final rapid decline. I may be wrong but I don't think there will be a recovery next year. I think it's slipped of the edge of the cliff and it's just a matter of how quickly it's going to hit bottom. -
Jim Eager at 08:22 AM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
Dale, you are leaving a factor out of your hypothetical question: that the storm itself, or at least its size, severity and duration, may be a result of the increasing warmth in the Arctic and the amount of open water present immediately prior to the storm. Both the climate of the Arctic and the physical nature of the sea ice has clearly changed, which means even random natural weather events, such as the storm, reflect that change at least in part. -
DSL at 08:10 AM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
Dale: "The 2012 abnormality is not." Wrong. As I pointed out upstream, area in 2012 recorded daily anomaly record lows for 109 consecutive days -- starting in late June. Before that streak began, there was another stretch of 16 days. 2012 was dropping faster than any other year well before August. Storm schmorm. -
DSL at 08:03 AM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
Dale, I've done a back of envelope to approximate the storm damage. I used SIA, though, because I think extent is a nearly useless measure (less error prone, but also much less useful). I cam up with a max additional drop of 150,000 km2 over the remainder of the melt season. There's a clear rebound in both area and volume records that suggests that the effect is actually much less than even that. I'd like to know how you'd calculate it, if you had access to all data. -
dana1981 at 07:54 AM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
Just as a technical note, Albatross is co-author on this post and did a lot of the important research. A lot of people are saying "Dana" - I want to make sure he gets credit for his work on this too. I think it's accurate to say that 2012 wouldn't have broken the record by as much if not for the storm. Just like we can say 2007 wouldn't have broken the record by as much if weather conditions hadn't been ideal. But the point remains that similar storms in previous years had very little impact on the eventual minimum; therefore, it's safe to say that this year's storm only could have had a significan influence on the minimum because the ice was already much weaker. So if you're blaming the storm, you're also blaming the long-term sea ice decline. -
Bob Loblaw at 07:49 AM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
Dale @35: ...and we see that your "skepticism" is totally one-sided. Replacing the 2012 weather with the 2007 weather is just as valid as your choice of replacing the storm with other weather from the summer 2012 - they are both mind games. You have absolutely no justification is assuming that "no storm" means "replaced with normal conditions". Why? Because that "normal conditions" of the rest of the summer of 2012 was exactly the type of conditions that created the storm of early August. The storm is the result of a combination of dynamics and energy transfers. If the storm hadn't happened, the pressures and energy build-up would had to be dissipated in some other fashion, and the rest of the weather on either side of the storm would also not be the same. And you have absolutely no idea what that different weather would have done to the ice. You can't just erase the physics of the storm and pretend that it would not have any other effect on the physics of the rest of the season. In effect, you have assumed your conclusion: you are convinced that "no storm" means less of a record, because you start from a position where "no storm" can only lead to weather that causes less ice loss. You are keeping the weather that leads you where you want to go, and magically erasing the weather that might lead you elsewhere. It's cherry-picking the weather that you want. It's not science. ...and you haven't said a thing about the graph I presented above, that shows that large parts of the melt 2012 season had ice loss rates that were on the greater side of "normal". All it would take for the 2012 record to reach the same magnitude - in the absence of the early August storm - would be for the melt rates on some of the "low melt" days to approach the melt on some of the "intermediate" days. And physics requires that to prevent the August storm, something else would have had to change in the weather around it. -
reg61 at 07:46 AM on 19 October 2012The Skeptical Science temperature trend calculator
Thanks for those clear explanations. Probably a Dhoo moment called for. -
Kevin C at 07:44 AM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
That is a hypothesis. Dana presents an alternative hypothesis. The distinction between the two hypotheses is that Dana examined previous Arctic storms in order to test his hypothesis. -
Dale at 07:05 AM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
Bob @32 I think "replacing" the storm with 2007 weather is not valid. We know from reports that expect for the storm, the 2012 summer was pretty ordinary, not conducive for high melt like 2007, and not conducive for slow melt. Therefore "under normal conditions" replacing the storm with 2012 style of weather is more appropriate. Which under those conditions, I can see how a new record would be set, but not to such a large margin. CoalGeologist @33 Fair points, and I agree. Moving goalposts are bad. But what we're talking about in this article is attribution, ie: how much ice melt did the storm or underlying conditions cause? We can all agree based on the long term trend that Arctic ice is shrinking due to more warmth in the region. We can all agree based on the long term trend that 2012 is an abnormality. But what caused the abnormality? Was it the underlying long term trend or natural variance? For that we look back at how other similar examples are done, ie precedents. If we look at long term temperature, the growth in temperature is attributed to the long term slow rising trend. Abnormalities (ie: higher or lower years by large margins) are attributed to natural variance (ie: El Nino,, volcanism, etc). Thus using the same principles, the underlying long term Arctic melt is attributable to the growing warmth in the Arctic. The 2012 abnormality is not. So what can you attribute such a large margin to? The storm. -
Composer99 at 07:02 AM on 19 October 2012What Role Did the Arctic Storm Play in the Record Sea Ice Minimum?
Dale: The problem is that your speculatory question is directly rebutted by evidence noted in the OP. One might say it has been pre-bunked. dana shows several previous years in the satellite record with similar major early-August storms, and no discernable effect upon eventual sea ice extent minima. In some years, the minimum extents are higher than previously and in others they are lower. If it were truly the case that the storm was a critical causal factor in this years' minimum, surely the other years would show consistent decreases. In addition, your claim ignores the vulnerability of the severely-deteriorated sea ice (as a result of ongoing warming) to storm activity, which I have already quoted from the OP's concluding remarks. The effects of the storm require, of necessity, the prior vulnerability of the sea ice to have had a significant impact on the eventual minimum. As far as I am concerned, that is as good as saying "the storm is not responsible". I might also add that your behaviour here, which has been characterized as 'fake skepticism' is consistent with many of your myriad other posts on this site. No one need assume anything about you when we can review your posting history, and it strikes me as unreasonable to expect us to ignore that history when commenting on this thread.
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