Guest Post by Willis Eschenbach
In a recent interchange over at Joanne Nova’s always interesting blog, I’d said that the slow changes in the sun have little effect on temperature. Someone asked me, well, what about the cold temperatures during the Maunder and Dalton sunspot minima? And I thought … hey, what about them? I realized that like everyone else, up until now I’ve just accepted the idea of cold temperatures being a result of the solar minima as an article of faith … but I’d never actually looked at the data. And in any case, I thought, what temperature data would we have for the Maunder sunspot minimum, which lasted from 1645 to 1715? So … I went back to the original sources, which as always is a very interesting ride, and I learned a lot.
It turns out that this strong association of sunspot minima and temperature is a fairly recent development. Modern interest in the Maunder sunspot minimum was sparked by John Eddy’s 1976 publication of a paper in Science entitled “The Maunder Minimum”. In that paper, Eddy briefly discusses the question of the relationship between the Maunder sunspot minimum and the global temperature, viz:
The coincidence of Maunder’s “prolonged solar minimum” with the coldest excursion of the “Little Ice Age” has been noted by many who have looked at the possible relations between the sun and terrestrial climate (73). A lasting tree-ring anomaly which spans the same period has been cited as evidence of a concurrent drought in the American Southwest (68, 74). There is also a nearly 1 : 1 agreement in sense and time between major excursions in world temperature (as best they are known) and the earlier excursions of the envelope of solar behavior in the record of 14C, particularly when a 14C lag time is allowed for: the Sporer Minimum of the 16th century is coincident with the other severe temperature dip of the Little Ice Age, and the Grand Maximum coincides with the “medieval Climatic Optimum” of the 11th through 13th centuries (75, 76). These coincidences suggest a possible relationship between the overall envelope of the curve of solar activity and terrestrial climate in which the 11-year solar cycle may be effectively filtered out or simply unrelated to the problem. The mechanism of this solar effect on climate may be the simple one of ponderous long-term changes of small amount in the total radiative output of the sun, or solar constant. These long-term drifts in solar radiation may modulate the envelope of the solar cycle through the solar dynamo to produce the observed long-term trends in solar activity. The continuity, or phase, of the 11-year cycle would be independent of this slow, radiative change, but the amplitude could be controlled by it. According to this interpretation, the cyclic coming and going of sunspots would have little effect on the output of solar radiation, or presumably on weather, but the long-term envelope of sunspot activity carries the indelible signature of slow changes in solar radiation which surely affect our climate (77). [see paper for references]
Now, I have to confess, that all struck me as very weak, with more “suggest” and “maybe” and “could” than I prefer in my science. So I thought I’d look to see where he was getting the temperature data to support his claims. It turns out that he was basing his opinion of the temperature during the Maunder minimum on a climate index from H. H. Lamb, viz:
The Little Ice Age lasted roughly from 1430 to 1850 … if we take H. H. Lamb’s index of Paris London Winter Severity as a global indicator.
After some searching, I found the noted climatologist H. H. Lamb’s England winter severity index in his 1965 paper The Early Medieval Warm Epoch And Its Sequel. He doesn’t give the values for his index, but I digitized his graph. Here are Lamb’s results, showing the winter severity in England. Lower values mean more severe winters.
So let me pose you a small puzzle. Knowing that Eddy is basing his claims about a cold Maunder minimum on Lamb’s winter severity index … where in Lamb’s winter severity index would you say that we would find the Maunder and Dalton minima? …
Figure 1. H.H. Lamb’s index of winter severity in England.
As you can see, there is a reasonable variety in the severity of the winters in England. However, it is not immediately apparent just where in there we might find the Maunder and Dalton minima, although there are several clear possibilities. So to move the discussion along, let me reveal where they are:
Figure 2. As in Figure 1, but with the dates of the Maunder and Dalton minima added.
As we might expect, the Maunder minimum is the coldest part of the record. The Dalton minimum is also cold, but not as cold as the Maunder minimum, again as we’d expect. Both of them have warmer periods both before and after the minima, illustrating the effect of the sun on the … on the … hang on … hmmm, that doesn’t look right … let me check my figures …
…
…
…
… uh-oh
…
…
Well, imagine that. I forgot to divide by the square root of minus one, so I got the dates kinda mixed up, and I put both the Maunder and the Dalton 220 years early … here are the actual dates of the solar minima shown in Lamb’s winter severity index.
Figure 3. H.H. Lamb’s England winter severity index, 1100-1950, overlaid with the actual dates of the four solar minima ascribed to that period. Values are decadal averages 1100-1110,1110-1120, etc., and are centered on the decade.
As you can see …
• The cooling during the Wolf minimum is indistinguishable from the two immediately previous episodes of cooling, none of which get much below the overall average.
• The temperature during the Sporer minimum is warmer than the temperature before and after the minimum.
• The coldest and second coldest decades in the record were not associated with solar minima.
• The fastest cooling in the record, from the 1425 decade to the 1435 decade, also was not associated with a solar minimum.
• Contrary to what we’d expect, the Maunder minimum warmed from start to finish.
• The Dalton minimum is unremarkable in any manner other than being warmer than the decade before the start and the decade after the end of the minimum. Oh, and like the Maunder, it also warmed steadily over the period of the minimum.
Urk … that’s what Eddy based his claims on. Not impressed.
Let me digress with a bit of history. I began this solar expedition over a decade ago thinking, along with many others, that as they say, “It’s the sun, stupid!”. I, and many other people, took it as an unquestioned and unexamined “fact” that the small variations of the sun, both the 11-year cycles and the solar minima, had a discernible effect on the temperature. As a result, I spent endless hours investigating things like the barycentric movement of the sun. I went so far as to write a spreadsheet to calculate the barycentric movement for any period of history, and compared those results to the temperatures.
But the more I looked, the less I found. So I started looking at the various papers claiming that the 11-year cycle was visible in various climate datasets … still nothing. To date, I’ve written up and posted the results of my search for the 11-year cycle in global sea levels, the Central England Temperature record, sea surface temperatures, tropospheric temperatures, global surface temperatures, rainfall amounts, the Armagh Observatory temperatures, the Armagh Observatory daily temperature ranges, river flows, individual tidal stations, solar wind, the 10Beryllium ice core data, and some others I’ve forgotten … nothing.
Not one of them shows any significant 11-year cycle.
And now, for the first time I’m looking at temperature effects of the solar minima … and I’m in the same boat. The more I look, the less I find.
However, we do have some actual observational evidence for the time period of the most recent of the minima, the Dalton minimum, because the Berkeley Earth temperature record goes back to 1750. And while the record is fragmentary and based on a small number of stations, it’s the best we have, and it is likely quite good for comparison of nearby decades. In any case, here are those results:
Figure 4. The Berkeley Earth land temperature anomaly data, along with the Dalton minimum.
Once again, the data absolutely doesn’t support the idea of the sun ruling the temperature. IF the sun indeed caused the variations during the Dalton minimum, it first made the temperature rise, then fall, then rise again to where it started … sorry, but that doesn’t look anything like what we’d expect. For example, if the low spot around 1815 is caused by low solar input, then why does the temperature start rising then, and rise steadily until the end of the Dalton minimum, while the solar input is not rising at all?
So once again, I can’t find evidence to support the theory. As a result, I will throw the question open to the adherents of the theory … what, in your estimation, is the one best piece of temperature evidence that shows that the solar minima cause cold spells?
Now, a few caveats. First, I want to enlist your knowledge and wisdom in the search, so please just give me your one best shot. I’m not interested in someone dumping the results of a google search for “Maunder” on my desk. I want to know what YOU think is the very best evidence that solar minima cause global cooling.
Next, don’t bother saying “the Little Ice Age is the best evidence”. Yes, the Maunder occurred during the Little Ice Age (LIA). But the Lamb index says that the temperature warmed from the start of the Maunder until the end. Neither the Maunder’s location, which was quite late in the LIA, nor the warming Lamb shows from the start to the end of the Maunder, support the idea that the sun caused the LIA cooling.
Next, please don’t fall into the trap of considering climate model results as data. The problem, as I have shown in a number of posts, is that the global temperature outputs of the modern crop of climate models are nothing but linear transforms of their inputs. And since the models include solar variations among their inputs, those solar variations will indeed appear in the model outputs. If you think that is evidence for solar forcing of temperature … well, this is not the thread for you. So no climate model results, please.
So … what do you think is the one very best piece of evidence that the solar minima actually do affect the temperature, the evidence that you’d stand behind and defend?
My regards to you all,
w.
[UPDATE] In the comments, someone said that the Central England Temperature record shows the cooling effects of the solar minima … I’m not finding it:
As you can see, there is very little support for the “solar minima cause cool temperatures” hypothesis in the CET. Just as in the Lamb winter severity data and the Berkeley Earth data, during both the Dalton and Maunder minima we see the temperature WARMING for the last part of the solar minimum. IF the cause is in fact a solar slump … then why would the earth warm up while the sun is still slumping? And in particular, in the CET the Dalton minimum ends up quite a bit warmer than it started … how on earth does this support the “solar slump” claim, that at the end of the Dalton minimum it’s warmer than at the start?
The Usual Request: I know this almost never happens, but if you disagree with something that I or someone else has said, please have the common courtesy to QUOTE THEIR EXACT WORDS that you disagree with. This prevents much confusion and misunderstanding.
Data: Eddy’s paper, The Maunder Minimum
Lamb’s paper, The Early Medieval Warm Epoch And Its Sequel
Berkeley Earth, land temperature anomalies
Sturgis, tephra deposit in the surrounding area is not the best measure of overall magnitude and intensity. What gets into the stratosphere is the better measure of its global impact and therefore significance climatically. Even better, when ice cores from both poles show the eruption, you can say to one and all, that was a big one. The eruption of 1257-58 shows up in North and South Pole ice cores and stands way above the signatures of other bi-polar sulfur and ash deposits, including Tambora’s.
sturgishooper says:
June 24, 2014 at 2:26 pm
As estimated in the various linked studies, some have found that the presumed Samalas eruption released about twice as much sulfate as Tambora, which ejected almost four times as much tephra as the older Indonesian event.
So Samales was much bigger than Tambora. Good to establish that.
If it were up to me, I’d count all the spots observable and measure the total area covered.
My question was not what you would do. I’ll repeat it:
svalgaard says:
June 23, 2014 at 11:15 pm
The proper weighting scheme to be compatible with the rest of the historical record is ‘no weighting’.
To continue with Socrates: do you agree with the above?
If so, should we not reduce the lone observers count to compensate for the overcount?
As for evidence of possible solar influence on interglacial climate fluctuations
The past few hundred year hardly qualify as ‘interglacial’.
Tonyb says:
June 24, 2014 at 2:22 pm
You’re welcome. That’s just Willis being Willis.
Thanks for all the hard & excellent work you’ve done on reconstructing paleotemperature data, & analysis thereof.
“””””…..Bob Weber says:
June 23, 2014 at 6:56 pm
george e. smith says:
June 23, 2014 at 6:36 pm
You can find standard definitions for everything I mentioned, and brightness is part of it. Notice you made a much much bigger deal out of the use of that word than I did, although Jack Eddy reported in the BBC video circa 1977 “The Sunspot Mystery” that people back during the Maunder Minimum observed the sun to be “dim”. That qualitative observation can be tested scientifically in this day and age. That video link is http://www.youtube.com/watch?v=v3frXY_rG8c . I recommend it for it’s historical perspective.
“”…. brightness is part of it. Notice you made a much much bigger deal out of the use of that word than I did, although Jack Eddy reported in the BBC video circa 1977 “The Sunspot Mystery” that people back during the Maunder Minimum observed the sun to be “dim”. ….”””
“”…. brightness is part of it. ……………observed the sun to be “dim”. ….”””
So OK, just what does the word …… DIM …… have to do with the word ……BRIGHTNESS……”” ??
Those two words, don’t even have the same number of syllables; let alone the same meaning.
I noticed YOU didn’t cite ANY of those “standard definitions” of everything you mentioned.
I’ve been using all of that terminology, continually for at least the last 55 years of gainful employment. I have shelves of standard textbooks, that go into them in interminable detail.
So I don’t actually need to know what your “standard definitions” references say. It’s my bread and butter, which is why I keep them all in my head..
I once wrote an extensive invited paper on radiometry and photometry, and its measures and units, for a very popular Electronics Industry weekly magazine, to educate electronic engineers on the metrology for LED light sources. That was more than 40 years ago.
The magazine editor “edited” my raw copy, “to make it more interesting to read.” Then he sent it to me, asking me to check it for technical correctness, and send it back.
Everywhere I had used some correct scientific unit or quantity or word, with precise defined meanings, the editor had simply replaced them willy nilly, with some street language synonyms from a thesaurus; well, to make it more interesting (and quite meaningless).
So I sent his script back to him with the short note; “It WAS technically correct, as I originally wrote it.”
The magazine published my App Note verbatim, and never changed a single word or punctuation mark.
The editor subsequently apologized for not understanding that scientific terms have specific meanings, and cannot be replaced by colloquialisms ; like “brightness” for example.
If you want to keep using incorrect terminology; go for it. I actually don’t care, that you do that. I do care that you mislead others.
Francis Grose (@JackPudden) says:
June 24, 2014 at 2:40 pm
“Several other tests have been described and
their results all indicate that the contribution of changing solar activity either through cosmic rays or otherwise cannot have contributed more than 10% of the global warming seen in the twentieth century.”
Sounds like a sober and well-supported analysis
Pamela Gray says:
June 24, 2014 at 2:44 pm
The geologists who set up the VEI disagree with you. VEI ratings are based upon tephra volume, as you easily could have found out had you bothered to look on the Internet.
http://www.agu.org/books/hg/v002/HG002p0143/HG002p0143.pdf
How many more times do I need to show you that higher sulfate record at the poles does not translate into greater climatic effect? Tambora’s massive ejection did have a global climatic effect.
I would have thought it obvious that if you want to claim that Samalas caused the Little Ice Age, you have at least to show that it had some climatic effect.
Time to quit digging yourself a deeper hole.
lsvalgaard says:
June 24, 2014 at 2:46 pm
You did not establish any such thing. As I’ve repeatedly shown Pamela, Tambora was about four times as massive as Samalas. Tephra and not sulfates is how eruptions are measured.
I guess I wasn’t clear enough. No, we should not reduce the observer count to compensate.
I also guess you’re less familiar with elementary earth history than I assumed. The Holocene is an interglacial. It started over 11,000 years ago but includes the past several hundred years right down to today. So, yes, AMO fluctuations since the Medieval Warm Period and Little Ice Age have occurred during an interglacial.
sturgishooper says:
June 24, 2014 at 2:59 pm
No, we should not reduce the observer count to compensate.
Then we would have an inhomogenous record which is useless for studies. If an observer uses a much larger telescope should we then not reduce his count to compensate?
So, yes, AMO fluctuations since the Medieval Warm Period and Little Ice Age have occurred during an interglacial.
That is like saying that what has happened the last five minutes is a millennium phenomenon.
William Astley says:
In case you missed it the planet has started to cool due to solar magnetic cycle 24. We can watch the cooling in real time with satellite data.
Thanks, William. To date, neither the RSS nor the MSU satellite temperature data show cooling. Their trends have been ≈ 0 for a decade and more.
What satellite record of global temperatures are you referring to that shows the cooling in real time?
Although the 17+ yr temp is flat, both the RSS UAH data show a 5-yr cooling trend of 2.5 C/century
Milodon
My bad. In noticed that In my previous teply to you My iPad decided It preferred the name Milton. Sorry.
Tonyb
lsvalgaard says:
June 24, 2014 at 3:05 pm
No. As I’ve advocated, adjust the smaller count up, if there’s reason to think that the other observer missed some spots.
You make no sense. Fluctuations on annual to decennial scale, like the AMO, PDO & ENSO, and on the centennial to millennial scale, like the MWP, LIA and previous similar warmer and cooler periods occur in this and other interglacials, as shown in all proxy records. That Bond cycles operate in interglacials at a similar frequency but less amplitude than D-O cycles during glacials is also well supported. This issue is what causes these fluctuations. Is it insolation, as has been established for the fluctuation between glacials and interglacials themselves, ie on the scale of ten to 100 thousand years?
IMO the evidence strongly suggests so.
oebele bruinsma says:
…….
Re LOD
Couple of years ago I wrote an article about LOD , but never put it on line. From two sets of data (geodesic and geomagnetic), by using simple filtering I produced two graphs now added to my CET-D comment above .
Tonyb says:
June 24, 2014 at 3:16 pm
That autofill is a bitch. Try typing Spanish on an English iPhone sometime. I could switch default languages, but that takes almost as much time, & the phone is starting to accept Spanish words anyway.
No worries. My real name is John, not Milo or Milton anyway.
The absurdity of Leif and Willis is comical. More will be leaving this site until their free run and control of this site is curtailed. So many valuable posters have left already because of them being able to run free with all of their repeated absurd statements. They are off way off. I think Leif is more or less not based in reality. I am serious.
You need (Anthony) at the very least to start posting articles in opposition to what they are trying to say. Secondly you need to reach out to those who oppose them . This way your site will once again be in balance. Right now it is not.
REPLY: See, here’s the thing, and there is no way of getting around this: 1) Willis and Leif don’t control WUWT, I do. 2) you haven’t refuted what they have to say about a solar climate connection, so you go ad hominem, say they are making absurd statements, that Leif is mentally imbalanced, and try to guilt me into banning them. From my perspective, that’s just not going to fly here. Feel free to be as upset as you wish, but please refrain from commenting like this any further unless you have some science to discuss. If you feel you can’t, then you are most certainly welcome to make good on your threat of leaving. – Anthony
Willis
You asked for data showing the sun climate connection. You are not ignoring me – you are ignoring Steinhilber . I gave you a reference to a specific Stenhilber paper that is what you choose to ignoring.
Leif’s stock answer to any work on GRF is to point out that there are some problems taking into account depositional processes in analyzing the data properly – truly an amazing discovery.
The Sturgishooper reference pretty well takes care of that.
I said
“Furthermore Fig 8 shows that the cosmic ray intensity time series derived from the 10Be data is the most useful proxy relating solar activity to temperature and climate. – see Fig 3 CD from Steinhilber
http://www.pnas.org/content/early/2012/03/30/1118965109.full.pdf
This paper shows the direct connection between the various LIA minima and GCRs
This should be read in association with my other comment above
“The value of the Steinhilber interpretations is indicated in the following link posted earlier by Sturgishooper
http://www.sciencedirect.com/science/article/pii/S0012821X12004748
“This suggests that studies which assimilate bipolar composite 10Be records in solar or cosmic ray
intensity reconstructions (e.g. Steinhilber et al., 2012), or variants,
such as the leading principal component of multiple records (e.g.
Muscheler et al., 2007b) are less likely to introduce spurious
climate-related signals than those assimilating 10Be records from
individual sites (e.g. Bard et al., 2000; Vonmoos et al., 2006;
Shapiro et al., 2011). Using multiple 10Be records in addition to
cosmogenic 14C (from tree rings), which has a very different
geochemical behaviour to 10Be, can help to further decouple the
climate signal from the 10Be record (e.g. Muscheler et al., 2007b;
Usoskin et al., 2009; Steinhilber et al., 2012″
Couple of questions,
1What do you think of Steinhilbers paper- specifically his Fig 3 CD
2 Do you not think that a reasonable case – a useful working hypothesis- can be made from Fig 4 at
http://climatesense-norpag.blogspot.com/2013/10/commonsense-climate-science-and.html
for a quasi millennial connection? (If you think that natural climate periodicities are not going to be quasi – you are in the wrong business)
2 If so where do you think we now stand relative to the late 20th century peak?
This link describes a new kind of data set that records volcanic explosiveness based on volcanic flux, as well as other measures, extrapolated from sulfur/ash records in ice cores. It describes the extent of stratospheric sulfur loading. This metric of volcanic significance carries global information. For the periods we are talking about related to global cooling, this kind of index provides information germane to this topic, whereas amount of tephra surrounding a volcano is not as germane. In terms of shear explosiveness into the stratosphere as measured by volcanic flux (total flux minus background flux), Samalas takes the prize by more than a length.
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&cad=rja&uact=8&ved=0CEkQFjAE&url=http%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1029%2F2011JD015916%2Fpdf&ei=ZfepU9zwBs-HyATynoDAAw&usg=AFQjCNHhAoZswLECaxKdbtP3ma97Pe8MCA&sig2=900fOILT6noCxAQwf1GB4Q&bvm=bv.69620078,d.aWw
sturgishooper says:
June 24, 2014 at 3:16 pm
No. As I’ve advocated, adjust the smaller count up, if there’s reason to think that the other observer missed some spots.
You are not answering the question. Careful analysis shows that for the weighting scheme no spots are missed, just the larger ones overcounted because of the weighting. So to be clear: if you have two observers counting the same spots but one is weighting and nobody else in the world is weighting should we not reduce the weighted count in order to get a homogeneous series? Analogously, if one observer measures a temperature in Fahrenheit and another in Centigrade, should we not convert one series to the other by using the appropriate scaling?
similar warmer and cooler periods occur in this and other interglacials
There is no data for solar activity in other interglacials, so you are overstating your case.
richardscourtney: The Null Hypothesis is a basic principle of the scientific method. This fact is not affected by Fischer having applied the Null Hypothesis to statistical testing in the 1930s.
nitpick: I think you mean R. A. Fisher.
Oppenheimer states that, “The global climatic impacts of large eruptions are known to scale, in a non-linear way, to the mass and distribution of sulphate aerosol formed in the stratosphere as a result of the atmospheric injection of sulphur gases (e.g. Robock, 2000).” Clearly, again, Samalas stands out. In terms of its ability to shoot its sulfur content up into the stratosphere and in huge amounts, the explosiveness of Samalas is unequaled in the data string studied by Oppenheimer.
For the purpose of this thread, I stand by my opinion that based on the literature review, Samalas stands out as the most significant and explosive volcano in the last 7000 years and certainly one of the most significant and explosive in the Holocene. Based on its signature, I have no qualms about accepting that it figured largely in the beginning years and I speculate decades of the slide down towards the depth of the last LIA in terms of its disruptive affect on ENSO processes that serve to recharge and discharge oceanic heat.
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=6&cad=rja&uact=8&ved=0CFUQFjAF&url=http%3A%2F%2Fonlinelibrary.wiley.com%2Fdoi%2F10.1002%2Fjoc.891%2Fpdf&ei=ZfepU9zwBs-HyATynoDAAw&usg=AFQjCNEOg3_dn4mRMN76bW81HT8bt8ln3w&sig2=1jV5_zjlsLN7uIKb8f91YQ&bvm=bv.69620078,d.aWw
Leif Svalgaard, thank you again for your many pertinent posts.
beng says:
June 24, 2014 at 10:07 am
———————————
Beng,
while there is considerable uncertainty regarding TSI, it is fairly safe to say it only varies around 0.1 to 0.2%.
The issue is spectral variance and its effect on energy accumulation in the oceans. Here TSI is not a useful measure as it does not account for depth of energy absorption. For selective surfaces such as our deep transparent oceans, depth of absorption has a significant role in rate of accumulation or discharge. The experiment posted up thread is a clear demonstration of this mechanism.
Willis Eschenbach says:
June 24, 2014 at 9:59 am
———————————-
“And no, Konrad, this is not an invitation to discuss your idee fixé, nor is it the thread for that. Please, let’s stick with solar minima, thanks.”
“idee fixe”… “monomania”..yes, yes, nice strawman. Well stabbed. Multiple physical principles, multiple separate experiments, falsely called one idea and then stabbed. Brilliant.
Lets stick with solar minima.
When I posted a comment regarding just one of my experiments, it was because it directly related to how spectral variance rather than minor TSI changes could effect energy accumulation in the oceans. The sort of thing that occurs at solar minima.
The problem here is we have little TOA UV data prior to 1978 and no accurate ocean temp data below 100m prior to 2003. The good news is the ARGO data base is building, and empirical experiment can tell us where to look.
Funny thing, I found this UV mechanism while looking at an entirely different issue. But it seams to match very closely to what David and Jo are looking at.
Dr Norman Page says:
June 24, 2014 at 3:24 pm
Leif’s stock answer to any work on GRF is to point out that there are some problems taking into account depositional processes in analyzing the data properly – truly an amazing discovery.
This has been known for several years now and is not controversial, e.g. http://www.leif.org/EOS/2009GL03804-Berggren.pdf
“the transport and deposition rate is influenced by atmospheric mixing, scavenging and snow accumulation” and “Periodicity in 10Be during the Maunder minimum reconfirms that the solar dynamo retains cyclic behavior even during grand solar minima. We observe that although recent 10Be flux in NGRIP is low, there is no indication of unusually high recent solar acitvity in relation to other parts of the investigated period [the last 600 years].”
http://arxiv.org/ftp/arxiv/papers/1004/1004.2675.pdf
“We have made other tests of the correspondence between 10Be predictions and the ice core measurements which lead to the same conclusion, namely that other influences on the ice core measurements, as large as or larger than production changes themselves, are occurring. These influences could be climatic or instrumentally based”.
Pamela Gray says:
June 24, 2014 at 3:25 pm
As I said, you really need to quit digging and lying more. Your link provides no such thing as “a new kind of data set that records volcanic explosiveness based on volcanic flux, as well as other measures, extrapolated from sulfur/ash records in ice cores”. Sulfates have been measured in ice cores since long before 2011. Nor have sulfates replaced tephra as the index of volcanic eruption explosivity, as you appear to try to insinuate.
However what your link does do however is explain why Tambora, despite being about four times as massive as the presumed Samalas eruption, appears in ice cores to have emitted only half as much sulfate.
“Three other events (1334, 1274, and 1235) are comparable to Tambora (Table 2) in volcanic flux magnitude. However, the actual atmospheric aerosol mass loadings by these volcanic events are probably not as large as that by Tambora, for, as discussed earlier, the Tambora flux in SP04 is much smaller than expected as a result of the significantly reduced accumulation rate in the period of 1500–1900 A.D. The Kuwae eruption and 1259 UE are the largest volcanic events in the second millennium A.D. in most Antarctica ice core volcanic records, except those from Dome C [Castellano et al., 2005], Siple Dome [Kurbatov et al., 2006], and DT401 [Ren et al., 2010], in which the Kuwae signal is smaller than that of Tambora. The magnitude of volcanic signals in low‐accumulation areas (e.g., Dome C and DT401) is highly variable, compared with signals in areas of moderate or high accumulation [Cole‐Dai et al., 2000]. Signals in the Siple Dome record may be significantly affected by the unusually high and variable nonvolcanic background at the at the coastal West Antarctica location [Kurbatov et al., 2006].”
And why was there a reduced accumulation rate during 1500 to 1900 at site SP04? The authors state that, “Usually, a significant shift in accumulation rate on a century timescale is a characteristic of climate change [EPICA Community Members, 2004; Li et al., 2009]”. However, they go on, such a reduction for so long hasn’t been reported previously. Never the less, it coincides with the LIA, and might reflect reduced snowfall during such a long, cold, dry spell.
The upshot is that Tambora’s apparently lower sulfate loading could be an artifact of deposition, not production.
You really ought to read all of the papers which you link.
In any case, you still haven’t offered any evidence that the 1257/8/9 event caused the LIA. On the contrary, your own sources state that doubling sulfates (if such a thing happened) doesn’t double the climatic effect.
Nor have you shown that Samalas, if that were it, is the biggest eruption of the past 7000 years. Based upon its estimated tephra volume of 40 km^3, it’s only a VEI 6 (10-100 km^3), while Tambora is a 7.
Matthew R Marler says:
June 24, 2014 at 1:13 pm
Thanks as always, Matthew. The “bar-room fight” is what is called a “metaphor” for a situation where there’s a fight going on but you don’t have a dog in the fight … the dog is a metaphor as well, but you knew all of that.
Again its a metaphor, Matthew. When I see a comment from you, for example, I metaphorically “snap to attention” because your ideas are worth listening to. But the name “tonyb” didn’t engender that response.
You go on to quote me saying:
Sorry, I’d quoted it in the previous comment so I figured that covered it. In any case, it was quoted from the paper he referred to, where he said:
Where is my “misunderstanding”?
By “Mannian garbage, I meant the Hockeystick and the various “stick-alikes” by Mann and others attempting vainly to rescue the Hockeystick from well-deserved oblivion. So yes, he did use Mannian garbage. Again, where is my misunderstanding?
Matthew, you’ve just proven conclusively that you don’t know what Tony meant by his unreferenced accusation that I misunderstood him. And this is no surprise, because nobody but Tony knows what he meant.
As to whether I should “care to reread what you wrote about what he wrote” in a vain effort to decipher his meaning, no, I wouldn’t care to do that. I used to do that. When someone tried something like that, I’d pore over his words and then respond to what I decided he was talking about … only to be told, often rudely, that I’d picked the wrong thing.
So I gave it up, and I’d advise you to do the same. It’s a fools errand. Instead, I do what I did above—I asked Tony what he meant.
Nope. After all the fighting I’ve done against the Hockeystick and its demon spawn (e.g here among others), anyone claiming that the Hockeystick is “essentially confirmed” is not my ally. Nor are they paying attention. Let me recommend to you what I said to Tony—take a week, go to climateaudit, and do a search on both the hockeystick and the NAS report. Both of them are trash, and anyone who thinks that the NAS report is fit for more than a series of post-evacuation exhaust pipe wipeups hasn’t done their homework.
In any case, I was serious about you being a decent and well-meaning guy, and I do snap to attention when I see your name on a post … tonyb, not so much.
w.
PS—And that doesn’t even touch the time when Michael Mann appropriated my ideas and published them as his own … so yeah, anyone saying that Mann’s work is “essentially confirmed” is no friend of mine, or of the truth for that matter …