Arguments
Recent Comments
Prev 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 Next
Comments 116401 to 116450:
-
TOP at 23:56 PM on 27 June 2010What causes the tropospheric hot spot?
J. Neuman, 1955 for an explanation of lapse rate change with latitude and season. J.G. Moore, 1956 Distinction between upper and lower troposphere trends. I. Thaler et al, 2010 Discussion of current models and recent satellite data. Trend is highly dependent on scenario chosen. -
Riccardo at 23:51 PM on 27 June 2010What causes the tropospheric hot spot?
RickG, if anything, it should be considered as a negative feedback. Indeed it's some forcing that causes the response of a reduced lapse rate which, in turn, increases OLR emission. Note that the opposite is true at mid and high latitudes. -
Doug Bostrom at 23:44 PM on 27 June 2010IPCC were wrong about Amazon rainforests
Oops, meant to say WG1 &WG2. WG3 is where things become really debatable. -
Doug Bostrom at 23:39 PM on 27 June 2010IPCC were wrong about Amazon rainforests
I should amend my earlier remarks to Willis. Willis, the reason I'm probably coming off as a bemused-to-irritated on this is for the very reason that you're clearly capable of spending your effort on more useful activities that dragging up done-to-death issues such as this one. On WUWT you've performed some noteworthy service and in fact have stuck your neck out to help set some of the more resistant folks there straight on some science basics. You've corrected the record on C02 attribution, you've assisted WUWT readers in understanding that there is in fact a phenomenon called anthropogenic warming, you've traced the path of anthropogenic pH change in the ocean. You've taken a bit of flack for that, no surprise. Despite all your unusually pragmatic work at WUWT, here you are regressed to grinding on IPCC process minutia of no actual significance. I don't understand it, it does not seem in character and when I read your post to Riccardo here I honestly wondered, "is this really Willis Eschenbach?" Maybe your effort at WUWT is about getting folks to understand they should now be touting adaptation but I don't really know, only you can say. What I can say with more confidence is that focusing on one miss out of thousands of accurate hits is to miss a major point, namely that the IPCC WG1 synthesis is overwhelmingly useful in bringing together a multitude of inputs to help understand a novel situation we've accidentally created on our planet. If adaptation is the new mode for people discomfited with the unfortunate facts we're creating on the ground, maybe it would be better to focus on sections of the synthesis other than WG1. The more into policy one goes the more there is to argue about, meanwhile the fundamental science portion is a pretty futile subject of discussion at this point, as you've been pointing out. -
RickG at 23:35 PM on 27 June 2010What causes the tropospheric hot spot?
Thanks David, I was thinking possibly a feedback if anything, but "neither" makes sense. If I understand, correctly its a result rather than a mechanism. -
David Grocott at 23:05 PM on 27 June 2010What causes the tropospheric hot spot?
RickG, Neither, it is simply a signature which the models says should be seen if the earth is warming sufficiently. -
Doug Bostrom at 22:36 PM on 27 June 2010IPCC were wrong about Amazon rainforests
...is the reason that this website is trying so hard to make folks think that the IPCC is blameless in this matter. More unfounded speculations, daubs of paint flung on a canvas to make an impression. What, are you not only a rhetorical artiste but telepathic? A mind-reader? Meanwhile, back in reality, aren't you becoming just a wee bit self-conscious about what a strange impression you convey when you're so obsessed with the image you're trying to portray here, and what odd little bits of arcana you're trumpeting as some sort of triumphant evidence of defect? Bottom line is that the IPCC has justifiable and clearly stated policies about what sort of expertise and publications quality they draw on to construct synthesis reports. Out of many thousands of such dependencies they have apparently flubbed less than a handful. In the case of the error here it was completely immaterial because it had no actual effect on the conclusion and the reason you must bring it up is because there's only known material error, the Himalaya matter, which you can discuss elsewhere here if you're rooted in the past. As I say Willis, you're definitely capable of better work than this and you ought not to waste your time on lunatic-fringe arcana. Finally, whether the IPCC relies on un-referenced puff pieces from the WWF is hardly "trivia" as you say ... It is -so- strange that you're so desperate to leave a final note in the air here that you'd keep repeating this. One more time, hopefully, unless you're absolutely intractable: Original author of the Amazon study in question, Nepstad: In sum, the IPCC statement on the Amazon was correct. The report that is cited in support of the IPCC statement (Rowell and Moore 2000) omitted some citations in support of the 40% value statement. -
Spencer Weart at 22:19 PM on 27 June 2010What causes the tropospheric hot spot?
According to Santer et al. (2008), International Journal of Climatology 28: 1703-22 [doi:10.1002/joc.1756], "there is no longer a serious discrepancy between modelled and observed trends in tropical lapse rates. This emerging reconciliation of models and observations has two primary explanations. First, because of changes in the treatment of buoy and satellite information, new surface temperature datasets yield slightly reduced tropical warming relative to earlier versions. Second, recently developed satellite and radiosonde datasets show larger warming of the tropical lower troposphere. In the case of a new satellite dataset from Remote Sensing Systems (RSS), enhanced warming is due to an improved procedure of adjusting for inter-satellite biases." -
RickG at 22:11 PM on 27 June 2010What causes the tropospheric hot spot?
Question. Would the "hot spot" be considered a forcing or feedback? -
David Grocott at 21:01 PM on 27 June 2010What causes the tropospheric hot spot?
Re: this sentence:The reason the hot spot in box c is so strong is because greenhouse warming is so strong compared to the other forcings.
I would say "...is because greenhouse warming has been so strong compared to other forcings over the last 100 years" as that is all the figure is showing. Non-CO2 forcings have been small, so the tropospheric response has been small. Perhaps someone could answer this for me: to pose a hypothetical question - if the current warming turns out to have been caused by changes in solar output would we expect to see an identical tropospheric hot spot? Presumably we would, as it's the amount of warming, not the type, that determines the existence of the hot spot, right? -
CBDunkerson at 20:40 PM on 27 June 2010Temp record is unreliable
BP #62, if what you say were true then would not the satellite and surface temperature results diverge more and more as time goes by? After all, your argument is essentially that the satellite temperature data was 'set' to conform to surface results (though in fact UAH originally came up with results significantly different from the surface results and only later came to line up after several errors were identified). However, now that those 'assumptions' needed to match the satellite record up are in place they are fixed. If the surface temperature continued to change, per the 'UHI error theory' for instance, then it should diverge from the satellite record which is still based on the assumptions needed to match up to the older temperatures. Yet we aren't seeing this sort of growing divergence. I believe that is because you are simply incorrect about the satellite record being deliberately 'set equal' to the surface record... as also demonstrated by the fact that they originally did not match and the primary adjustments made since then have had to do with correcting for sensor drift rather than baselining to the surface data. -
Riccardo at 20:32 PM on 27 June 2010IPCC were wrong about Amazon rainforests
By the way, the IPCC procedure does not exclude the use of non peer-reviewed papers. Though, I agree thet it's not a good choice to use them, in particular when the proper peer reviewed papers are available. Definitely it should be avoided. But I'm way more interested in the science (the substance) than in the formal procedures, and the former looks correct and supported by proper scientific papers. -
Phil at 20:02 PM on 27 June 2010What causes the tropospheric hot spot?
Just a typo, John. I think 3 paras up from the bottom; last sentence - the word "equivocally" should be "unequivocally"Response: Fixed, thanks for the tip. Dang semantic glitches. -
Riccardo at 20:01 PM on 27 June 2010IPCC were wrong about Amazon rainforests
If we care about the form more than the substance, we should also check the ortography in the IPCC reports. After all, if one cannot write in good english how could he ever claim to know the science? -
Willis Eschenbach at 19:56 PM on 27 June 2010IPCC were wrong about Amazon rainforests
doug_bostrom at 17:16 PM on 27 June, 2010 I had said:... Now, it's possible they were relying on the 1994 document (although we have only this website's word for it). But I find nothing in that document that makes the 40% claim either ... perhaps someone could quote where in the 1994 document the 40% claim was made.
You replied:Original author of the Amazon study in question Nepstad:
In other words, you can't find anything in the 1994 document that supports the 40% claim ... and neither can Nepstad. He gives no citation, he only repeats the claim that it was correct, and says that Rowell and Moore "omitted some citations". Well ... yes. It is those "omitted citations", that neither you nor Nepstad have provided, that I am asking for. Where did the "40%" claim come from? Nepstad says that the WWF authorsIn sum, the IPCC statement on the Amazon was correct. The report that is cited in support of the IPCC statement (Rowell and Moore 2000) omitted some citations in support of the 40% value statement.
So it's your impressionism versus the ultimate authority on the matter, the fellow who actually did the research to which the citation trail was supposed to lead, in other words reality.... had originally cited the IPAM website where the statement was made that 30 to 40% of the forests of the Amazon were susceptible to small changes in rainfall.
Again, this sounds good. But my search of the IPAM website doesn't reveal any citations to the 40% figure there either. So where did it come from? Finally, whether the IPCC relies on un-referenced puff pieces from the WWF is hardly "trivia" as you say ... it goes directly to their claims of scientific credibility, and is the reason that this website is trying so hard to make folks think that the IPCC is blameless in this matter. -
Doug Bostrom at 17:16 PM on 27 June 2010IPCC were wrong about Amazon rainforests
Willis, the problem here is that you're so keen on your impressionist artwork, you're painting a picture that does not resemble reality. Your claim: Now, it's possible they were relying on the 1994 document (although we have only this website's word for it). But I find nothing in that document that makes the 40% claim either ... perhaps someone could quote where in the 1994 document the 40% claim was made. Original author of the Amazon study in question Nepstad: In sum, the IPCC statement on the Amazon was correct. The report that is cited in support of the IPCC statement (Rowell and Moore 2000) omitted some citations in support of the 40% value statement. So it's your impressionism versus the ultimate authority on the matter, the fellow who actually did the research to which the citation trail was supposed to lead, in other words reality. As I say, you're resurrecting this trivia because it's useful rhetoric, if nobody bothers to correct you. I've read some of your stuff on WUWT, you're capable of producing much original and entertaining pieces so it's baffling that you'd resort to such a stale technique. -
Willis Eschenbach at 17:01 PM on 27 June 2010IPCC were wrong about Amazon rainforests
doug_bostrom at 10:24 AM on 27 June, 2010Resurrecting "Amazongate?"
Nope. I bring it up to show that the IPCC did not follow its own guidelines, and that there was nothing at the end of the citation trail that supported the 40% number.Now, I am not saying that the claim is wrong. I do not know whether it is or not.
But you'll bring it up because it's handy rhetoric. -
ScaredAmoeba at 16:50 PM on 27 June 2010Astronomical cycles
There appears to be an 'Article in Press' version of the Scafetta paper over at SPPI The fact that SPPI [of Monckton infamy] received what was probably an embargoed pre-publication copy could easily lead one to draw all manner of conclusions about the motives behind this. Scafetta has produced [ahem]poorweak papers in the past and I suspect this attempt is just more of the same. -
gallopingcamel at 14:15 PM on 27 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
Oops! I meant #62! -
gallopingcamel at 14:14 PM on 27 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
John Cook, My apologies for getting "Off Topic" in #69. I am impressed by the fact that nobody on this blog is panic stricken by the prospect that north pole ice sheet may be smaller in September 2010 than it was in 2007. -
Lon Hocker at 11:47 AM on 27 June 2010Is the long-term trend in CO2 caused by warming of the oceans?
Oops, should have been "increases the uptake" instead of "reduces the uptake" -
Lon Hocker at 11:45 AM on 27 June 2010Is the long-term trend in CO2 caused by warming of the oceans?
Peter: Thank you for the excellent comment. I agree with pretty much everything you wrote. The carbon ratios support the emission of CO2 from the equator and absorption near the poles with a half time of about 5 years, regardless of model, as long as you accept the 100GtC flow. No question that there is a net flow of CO2 into the ocean from anthropological sources. The higher atmospheric CO2 due to anthropogenic sources reduces the amount that would have been emitted by the ocean for the same temperature increase (and decreases the uptake), and that would have been a clearer description than my stating that it came from the oceans. With a 5-year tome constant, the anthropogenic contributions to the CO2 increase would be about 25% of the observed increase, leaving the rest for the temperature change. I realize that this is an emotional subject for all, and I likely would have been more politic to not have written such a aggressive headline! In any event the science is far from settled, and I wanted to present a contrasting argument to that usually accepted. I greatly value postings, such as yours, that provide information and opinion dispassionately . I know that my understanding of this is far from complete, and I am open to changing my mind on pretty much everything, except for the Mauna Loa and satellite data, and my understanding of math and calculus! Again, thank you, and I would enjoy hearing more of your perspectives. -
Berényi Péter at 11:03 AM on 27 June 2010Temp record is unreliable
#61 Ned at 00:20 AM on 5 April, 2010 The close agreement between satellite and surface temperatures is a bit of a problem for those skeptics who believe that the surface record is hopelessly contaminated by UHI effect Ned, the problem with satellite "temperatures" is that satellites do not measure temperature, not even color temperature, but for a specific layer of atmosphere (e.g. lower troposphere) brightness temperature is measured in a single narrow IR band. This measurement may be accurate and precise, but it is insufficient in itself to recover proper atmospheric temperatures. In order to make that transition, you need an atmospheric model. With the model atmosphere you can calculate the brightness temperature backwards and tune parameters until a match is accomplished with satellite brightness temperature data. Then you can look at the lower troposphere temperature of the model and call it temperature. However, with no further assumptions, the relation is not reversible, i.e. many different atmospheric states lend the same brightness temperature as seen from above. The very assumptions in the model, that make reverse calculations possible are the hidden backlink to surface temperature data. For there is no other way to verify model reliability than compare it to actual in situ measurements. Therefore if the surface temperature record is unreliable, so are atmospheric models used to transform satellite measured brightness temperatures to atmospheric temperatures. That makes the whole satellite thing dependent on surface data, in spite of independent sensor calibration methods. -
Doug Bostrom at 10:24 AM on 27 June 2010IPCC were wrong about Amazon rainforests
Resurrecting "Amazongate?" Now, I am not saying that the claim is wrong. I do not know whether it is or not. But you'll bring it up because it's handy rhetoric. IPCC has something like a "four nines" reliability record with cites, so dredging up this silliness is only going to continue playing badly for those using it for impressionist art purposes. Read what Nepstad himself had to say. Senior Scientist Daniel Nepstad endorses the correctness of the IPCC’s (AR4) statement on Amazon forest susceptibility to rainfall reduction: "The IPCC statement on the Amazon is correct, but the citations listed in the Rowell and Moore report were incomplete. (The authors of this report interviewed several researchers, including the author of this note, and had originally cited the IPAM website where the statement was made that 30 to 40% of the forests of the Amazon were susceptible to small changes in rainfall). Our 1999 article (Nepstad et al. 1999) estimated that 630,000 km2 of forests were severely drought stressed in 1998, as Rowell and Moore correctly state, but this forest area is only 15% of the total area of forest in the Brazilian Amazon. In another article published in Nature, in 1994, we used less conservative assumptions to estimate that approximately half of the forests of the Amazon depleted large portions of their available soil moisture during seasonal or episodic drought (Nepstad et al. 1994). After the Rowell and Moore report was released in 2000, and prior to the publication of the IPCC AR4, new evidence of the full extent of severe drought in the Amazon was available. In 2004, we estimated that half of the forest area of the Amazon Basin had either fallen below, or was very close to, the critical level of soil moisture below which trees begin to die in 1998. This estimate incorporated new rainfall data and results from an experimental reduction of rainfall in an Amazon forest that we had conducted with funding from the US National Science Foundation (Nepstad et al. 2004). Field evidence of the soil moisture critical threshold is presented in Nepstad et al. 2007. In sum, the IPCC statement on the Amazon was correct. The report that is cited in support of the IPCC statement (Rowell and Moore 2000) omitted some citations in support of the 40% value statement. -
Willis Eschenbach at 09:38 AM on 27 June 2010IPCC were wrong about Amazon rainforests
Riccardo, thanks for the links. The WWF document cites the Nature document (Nepstad 1999) as their source for the statement that"Up to 40% of the Amazonian forests could react drastically to even a slight reduction in precipitation".
I don't find that. The nearest I could find is a quote in the 1994 paper that supports the statement referred to in the head post:"A 1994 paper estimated that around half of the Amazonian forests lost large portions of their available soil moisture during drought."
Yes, forests lose soil moisture during a drought. That is a very different statement from saying that the Amazon could "react drastically to even a slight reduction in precipitation." In fact, the 1994 paper says that in 2001, half of the Amazon suffered a 50% loss in soil water ... but it says nothing about that causing a "drastic reaction". I find nothing in the cited document that makes the 40% claim. This website says that the WWF citation is incorrect, that they really were relying on a 1994 document, Nepstad 1994. It is unknown how this website came to that conclusion ... but the practice of randomly substituting one citation for another hardly inspires confidence. Now, it's possible they were relying on the 1994 document (although we have only this website's word for it). But I find nothing in that document that makes the 40% claim either ... perhaps someone could quote where in the 1994 document the 40% claim was made. Now, I am not saying that the claim is wrong. I do not know whether it is or not. I do think, however, that for the IPCC to rely on a WWF document whose cited reference for a claim does not support what the WWF document says is ... well, it is far away from Pachauri's claim that the IPCC depends 100% on peer reviewed science. This is not even second-hand peer reviewed science, the citation doesn't support the claim. And for this website to say that the WWF document is really referring to a totally different paper (and one which does not contain the 40% claim either) is Monday morning quarterbacking. You present no evidence at all that the WWF was referring to the 1994 paper. Now that you know that the 1994 paper does not contain anything even remotely similar to the claim that "Up to 40% of the Amazonian forests could react drastically to even a slight reduction in precipitation", I suppose that you could come up with some other citation that kinda supports the claim if you squint at it in the right way ... but that's not the point. The point is that the IPCC relied on a WWF paper which was not peer-reviewed, and the citation listed for that WWF claim did not back up the claim ... Finally, you say:However, the 40% figure comes from several other papers by the same author that the WWF failed to cite. ... In 2004, new rainfall data showed that half of the forest area of the Amazon Basin had either fallen below, or was very close to, the critical level of soil moisture below which trees begin to die (Nepstad 2004).
Sorry, not possible. The WWF paper is not dated, but the most recent citation is from 2000, and it refers to 2001 as "the future", viz:So when will the next El Niño occur? Scientists at the American Climate Prediction Centre believe that La Niña conditions will prevail globally until March 2000 and it is too early to say when the next El Niño will be. However, the Eighth ASEAN Ministerial meeting on Haze in August concluded that as “La Niña is expected to weaken by the end of this year, meteorological experts have predicted a likely recurrence of dry conditions associated with the El Niño phenomenon next year or by 2001”.
So unless WWF has invented time travel, the idea that the WWF "failed to cite" a 2004 document is simply not possible ... -
Riccardo at 07:58 AM on 27 June 2010IPCC were wrong about Amazon rainforests
For the lazy readers, here's the Global Review of Forrest Fires, Nepstad 2004, Nepstad 2007 and Philips 2009. And should the webmaster at WHRC decide to move their pages again, we won't let them hide anything: Nepstad, D., P. Lefebvre, U. Lopes da Silva, J. Tomasella, P. Schlesinger, L. Solórzano, P. Moutinho, D. Ray, and J. Guerreira Benito. 2004. Amazon drought and its implications for forest flammability and tree growth: a basin-wide analysis. Global Change Biology 10(5):704-717. Nepstad, D.C., I.M. Tohver, D. Ray, P. Moutinho, and G. Cardinot. 2007. Mortality of large trees and lianas following experimental drought in an Amazon Forest. Ecology 88(9):2259-2269. John, you might want to update your link and delete this comment. -
gallopingcamel at 07:53 AM on 27 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
CBDunkerson (#54), No big deal. When one is looking at the poles satellite data would be more convincing. Somewhere on another thread it was shown that there are only a handful of high latitude ground stations in the NASA and NOAA data bases. Perhaps you or Berenyi Peter can say how many ground stations there are above 66 degrees latitude. I suspect that the number is too small to justify the fine grained contours seen on NASA anomaly maps.Moderator Response: There's no specific thread (yet) for discussion of polar temperature measurement and interpolation so for the time being please continue discussing the polar instrumental temperature record on the Temperature Record Is Unreliable thread. Thanks! -
Doug Bostrom at 07:03 AM on 27 June 2010IPCC were wrong about Amazon rainforests
Welcome to Skeptical Science, Willis. Do you have anything more substantial to offer other than pointing out expired links? -
Willis Eschenbach at 07:00 AM on 27 June 2010IPCC were wrong about Amazon rainforests
Two of your links go nowhere. The third says nothing about "up to 40% of the Brazilian forest". How is this supposed to convince anyone? -
J Bowers at 06:56 AM on 27 June 2010How Jo Nova doesn't get past climate change
To complement this post, I highly recommend Prof. David Greenwood's comment at Climatesight, which is a very lucid description of what we know. http://climatesight.org/the-credibility-spectrum/#comment-2320 Jo Nova should it read it, too, especially as David Greenwood started out as a sceptic. -
CBDunkerson at 05:41 AM on 27 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
It's just another aspect of the old 'we cannot predict the weather so we cannot predict climate' fallacy. No, we can't precisely predict the minimum sea ice extent in any given year... but that doesn't change the fact that the long term trend is clearly in sharp decline and we CAN predict eventual complete melt of the Arctic sea ice in Summer. That said, sea ice predictions are constantly improving and have now entered the realm of having some practical usability... specifically they've now got a good enough grasp on some of the dynamics to provide estimates of coastal sea ice stability about a week in advance. This is similar to weather prediction or volcano monitoring... so long as the prediction is limited to situations we have a good handle on they have some viable utility. There is a good article on the subject here. -
Peter Hogarth at 05:29 AM on 27 June 2010Ocean acidification
Berényi Péter at 01:56 AM on 27 June, 2010 Being charitable, I see what you have done on your final charts. With hindsight an obvious misunderstanding that should be very quickly clarified here. When we talk about “ocean acidification” we are really talking about pH changes in the upper layers, and not the entire water column. As you have found, deeper waters are much less alkaline anyway (pH around 7.6 at around 700m in this case) and clearly it is the interaction with increasing atmospheric CO2 in the upper layers that is driving the “acidification” process - top down. If you had tracked down and read Dore 2009 (linked above) and looked at figures 1 and 2 you might have saved yourself a bit of aggravation. The variation of pH with depth, and the rate of change of pH with depth, for both the measured and “calculated” values, are shown in figure 2 and it is definitely worth showing on this thread, though I would advise looking at the original, as there is a pleasing level of detail.
Hope this is all starting to make sense.
-
Philippe Chantreau at 04:58 AM on 27 June 2010Ocean acidification
Well it's a good thing that Peter, Riccardo and Doug were here to audit the auditor, isn't it? Let's see what kind of language we find in the "audit": "Outrageous, impermissible, no trend whatsoever." All generously sprinkled with subtle suggestions of incompetence or fraud, based on a superficial and rather incompetent "audit" that the auditor himself now acknowledges as needing to be entirely redone. Perhaps BP should hold on the emotional response, the grandiloquent language and the veiled suggestions of fraud or incompetence until absolute certitude is established that someting is amiss. -
dhogaza at 04:57 AM on 27 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
"I have to disagree with this because one thing it does tell us is just how good our understanding of arctic sea ice is. These are the best arctic scientists. Its good to know just how good they are given so much rides on what they are telling us. It's a good complement to peer-review." What they know is arctic sea ice predictions will always be less reliable than long-range weather forecasts, because the variability between years depends so much on weather. If weather forecasters were able to tell arctic sea ice experts what wind patterns (and the partially dependent water circulation patterns), temp anomalies, etc lie in store between now and the third week of September, sea ice forecasting would be far more accurate. But the weather people can't, and therefore sea ice minimum forecasts are guaranteed to be a crapshoot. -
Doug Bostrom at 04:38 AM on 27 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
One of the SEARCH predictions might be spot-on this year but that's not going to tell us much about the skill of the method employed. Although we ought to be happy that skills change and improve over time, from another perspective it would indeed be interesting to see the exact methods chosen by each group using a reproducible system applied over several years' time, maybe a decade. Short of that one year is going to teach us very little about the validity of any system of prediction against the other. As Chris suggests this is at the level of a spectator sport for us, or maybe watching tournament poker. It's fun (maybe in a morbid fashion) but shouldn't be taken too seriously. Trends are what we should be paying attention to from a more serious perspective. -
chris at 04:22 AM on 27 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
HumanityRules at 03:47 AM on 27 June, 2010 I have to agree with CBW here. We may understand Arctic sea ice quite well, but that doesn't mean that our single year predictions will necessarily be accurate. Predictions should encompass both the essential scientific understanding of sea ice response to warming and its seasonal progression (likely increasingly good) and the inherent uncertainty that results from stochastic variability (aka "weather" in this context). Sea ice response to global warming should increasingly be predictable in relation to the longer term trend that averages stochastic variability. Prediction of yearly levels is fun for the peanut gallery, but doesn't say a huge amount about our understanding of Arctic sea ice unless we (i.e. those that study this) have a good handle on the predictability of weather-related influences. My prediction is lots of blogospheric hot air to come! -
HumanityRules at 03:47 AM on 27 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
35 CBW at 01:27 AM on 26 June, 2010 "I find all of these predictions interesting, but not particularly helpful to the discussion of AGW" I have to disagree with this because one thing it does tell us is just how good our understanding of arctic sea ice is. These are the best arctic scientists. Its good to know just how good they are given so much rides on what they are telling us. It's a good complement to peer-review. -
HumanityRules at 03:39 AM on 27 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
29 doug_bostrom at 16:19 PM on 25 June, 2010 "Further to HR's thoughts about psychological influences on predictions" No psychological angle from me, are you referring to my use of the word bias? If so what I meant is that the very low 2007 extent is in someway playing through the different methods used to make the prediction. The most likely thing is because so much ice disappeared in 2007 we have very little multi year ice, this effect will continue until next year. I suspect the methods give too much value to this lost ice. -
HumanityRules at 03:33 AM on 27 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
25 Neven "I've also written a piece on the Cryosphere Today archive data and the discrepancy with the daily ice concentration map on the front page. No conclusions, unfortunately, but the archive maps look fishy to me." They are not fishy, they just use a different colour scale compared to the images on the front. I don't understand why they don't bother to be consistent. -
Doug Bostrom at 02:56 AM on 27 June 2010Sea level rise is exaggerated
Dan, rhetorical laughter is not a persuasive argument. You need to undo some statistics in sufficient detail to show how the measurement uncertainty reported by Donnelly is in error: This 700-year record from Barn Island provides a SLR estimate free of vertical displacement due to autocompaction of the peat column. A linear rate of rise of 1.0 ± 0.2 mm/year intersects all the 2s uncertainty boxes of the record from the 14th to the mid-19th century (Figure 2). Linear regression of the NYC tide-gauge data reveals an average rate of SLR of 2.8 mm/year from 1856–2001 A.D. Why don't you attack the Donnelly paper in detail? Until you do so your credibility does not seem equal to that of the authors you're critiquing. -
CBDunkerson at 02:05 AM on 27 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
gallopingcamel, does it matter? Given that the satellite and ground temperature records match other than minor variations, as even the UAH satellite team acknowledges, what's the difference? That said, the anomaly map in question was compiled by NASA from ground station data. -
Berényi Péter at 01:56 AM on 27 June 2010Ocean acidification
#60 Peter Hogarth at 10:21 AM on 26 June, 2010 It is a shame you get angry instead of taking time to be more thorough and thoughtful Yes, it is. Let me apologize for that. Fortunately you guys are here to set things straight. What I have actually done is to lump together pH measurements for all sites (there are 24 of them, STNNBR 1-19,50-52,60-61) and all depths (down to 4909.7 dbar, that's about 4821 m). This is what is shown in the graphs above and this is why pH values are so low. Now I see mean surface values are defined as average of measurements taken between 0-30 dbar, that is, the upper 30 m of ocean. As for the sites, Aloha is STNNBR 2. I can see two more, Kahe (1) and Kaena (6). Could not find documentation for the rest. It may be due to the fact neither hot*.sea nor Readme.water.woce referenced in the BEACH Water Column Chemical Data Format Document are to be found at the FTP site.
As 87.4% of all measurements were performed at STNNBR 2 (Aloha), depth must be the real problem. At that site only 17.2% of measurements were done "at surface" (down to 30 dbar).
With these in mind I will redo my analysis and let you know the results.
I assume pH calculations based on other parameters were done by the co2sys. As source code is not available at the CDIAC site, it is a bit cumbersome to perform a proper audit. Documentation of algorithms implemented is also deficient. IMHO no scientific work should be based on closed source applications.
-
Peter Hogarth at 01:47 AM on 27 June 2010Ocean acidification
Berényi Péter at 04:34 AM on 26 June, 2010 I anticipate that some may argue that the ALOHA data set could be some freak regional anomaly. I mentioned that other oceans and regions are showing similar trends.
From NOAA coral reef watch for Greater Caribbean region. Data is surface Aragonite saturation state (used because this is related to coral calcification rates). This is directly proportional to carbonate ion concentration, and hence indirectly to pH. It is up to date and based on ongoing geochemical measurements backed by modeling based on satellite measurements of SST etc. Solid points are confirmed measurements, open points are preliminary. Methodology is described here
There are also long time series (25 years) for the high North Atlantic Olafsson 2009 and an admittedly limited number of others.
Whilst it is true we do not have a global monitoring network for ocean chemistry yet, we do have enough information from continuous independent measurements from various locations to state that the change in Ocean pH (call it what you will, semantics won’t alter the data) is a reality and is directly caused by the increased atmospheric CO2. We know that this pCO2 increase is a global phenomenon, but is interestingly highest in the North Atlantic.
Feely 2010 et al call for a new comprehensive integrated observational network to maintain and increase the reliability and coverage of our data. Take a look at the organizations below the author list. This represents a great deal of collective expertise. To gain further insight into the reality of what we are measuring look at the presentations in pCO2 workshop 2007
These are sobering. Increased pCO2 is evident almost everywhere we look, it tracks the steadily rising atmospheric CO2, mostly just below, meaning on average the Ocean is a sink. For example:
Many areas previously identified as CO2 sources are now unambiguously net sinks. Global average pH is steadily decreasing in the upper layers. Some small comfort may be derived from the possibility that reducing Arctic ice cover will allow a significant increase in area of open water that will increase the net CO2 sink.
-
CBW at 01:37 AM on 27 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
dhogaza: "There are problems with melt ponds on top of the ice fooling the various ice measurement algorithms, but year-to-year comparisons should still be apple-to-apple." This isn't quite true. If surface temperatures are warmer than normal, you could see more melt ponds, which would tend to cause an underestimation of ice area. At the same time, you could have colder sea temperatures keeping the ice from melting through. Given arctic temperatures this year, it's likely that at least the first part of this is happening. If the second part is also happening, we'll likely see a recovery in ice volume (from the straight down trajectory PIOMAS is currently showing), and ice area, once the freezing starts again. But it's unlikely to move the ice volume back to anywhere near the 1979-2009 trend line. That looks broken for good. In any event, the existence of abnormally extensive melt ponds is in itself an important observation. Either way, things are warming up in the arctic. -
dhogaza at 23:59 PM on 26 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
a_yeeles "Precisely. Which is why, as AMSU-A shows global temperatures continuing to track well above average, an exceptional arctic ice season may well be in prospect." People talk about weather patterns and melt because water is a much more effective melter of sea ice than warm air. The warmer temps are going to accelerate melting, of course, but for a truly exciting melt season we need more than that. We need ice being pushed down from the arctic basin into the (relatively) balmy narrows of the Nares Strait, or the ocean south of the Fram Strait. At least, that's what the 2007 season told us. If it stays super-warm up there over the next three months, as it is currently doing, maybe that will have a bigger effect on extent and area of coverage and the movement of ice into warmer waters won't be so important. Each day that passes leads me to believe we might, as you say, have a very low minimum extent. The next four weeks will tell us a lot. -
gallopingcamel at 23:30 PM on 26 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
CBDunkerson (#46), Is that temperature anomaly map based on satellite or ground station data? -
daniel at 22:03 PM on 26 June 2010Sea level rise is exaggerated
To doug-bostrom post # 19 Sorry it has taken me a month to get back to you doug. You're links were a little hard to follow to be honest and I will say that it is probably because they are lengthy wafflings about how we can test the outputs of a simple two term equation to a "simulated" millenial scale model and recent sea level observations. We all know that water expands when heated and although there may be some credibility issues with the global temperature record of the last 200 years we can safely assume that things have warmed a bit since the LIA and that the sea level may have responded. The question is, just like the temp record, is it unprecedented? Rather then spend time reading how the two term equation predicts future sea levels I decided to turn my attention instead to the papers cited by the above article. The article claims that skeptics are guilty of interpreting small recent trends from noisy data as significant. Here's a quote: "The lesson from this is to treat with skepticism anyone who concludes long term trends from several years of a noisy signal (after all, skepticism should cut both ways)" Yes indeed it does cut both ways. What the author of this article doesn't realise is that the two papers cited for paleo sea levels make the mistake of claiming an unprecedented rapid sea level rise from very noisy data. The Donnely paper, on the reconstruction of SLR at Barn Island Connecticut, on it's own is simply an utter joke. 10 or so paleo samples with quite large height and age uncertainties are used to construct a linear 1mm/year sea level trend over 1300-1850 A.D. There is more than enough slack in this data to periodically reproduce the apparently rapid sea level rise of 2.8mm/year in the NYC tide gauge data of the last ~150 years (cited and compared to by the authors). The Gehrels paper I would say is a much more commendable attempt at reconstructing sea levels off the west Icelandic coast. The low resolution issue is adressed but the uncertainty issue does not disappear. Height and age error estimates again provide more than enough slack to allow the reproducuction of the modern rates of sea level rise. The authors fail to discuss the suspicious nature of the sudden and relatively linear increase in sea level reconstruction at ~ 1800 A.D. which also marks the point at which the age of the reconstruction is measured by Pb and Cs isotopic ratios and paleo-magnetism rather than the seemingly much less certain C14 analysis. As I have mentioned elsewhere on this website (see "There is no concensus" argument page) the claim that "experts" of climate science have a more credible opinion on this issue is highly insulting to scientists from other fields. Scientists who after having found the time and inclination to review the data of climate scientists are utterly apalled at the conclusions drawn. -
a_yeeles at 19:09 PM on 26 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
Oops, sorry Link should be http://discover.itsc.uah.edu/amsutemps/ Apologies -
a_yeeles at 19:06 PM on 26 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
CBDunkerson #46 "Actually, temperatures in the Arctic have been further above normal than any other part of the world." Precisely. Which is why, as AMSU-A shows global temperatures continuing to track well above average, an exceptional arctic ice season may well be in prospect. ( http://discover.itsc.uah.edu/amsutemps/execute.csh?amsutemps ) -
Pete Dunkelberg at 11:18 AM on 26 June 2010September 2010 Arctic Ice Extent Handicapping Via ARCUS
"... or if the reports of rotten older ice last year turn out to be important." As a_yeeles says, the heat is important. BTW, watch for new information Tuesday.
Prev 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 Next
