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
thingadonta says:
June 25, 2014 at 8:08 pm
Try this. Put a running average of some kind on the sunspot data. Of course it has to be a trailing average, since otherwise the future affects the present.
Now, run that average and see what happens in the Dalton minimum. As you point out, what happens is that when the sun cycles drop in size, so does the long-term average.
There are two big problems with this picture, however. The first is that the long-term average will not start to increase until the first regular-sized solar cycle … but in both the Maunder and the Dalton, the temperature starts rising way before that. And since the sun is not causing the rise in temperatures … why should we believe it caused the fall?
The second problem is more subtle, and is the problem that I was pointing to above. For your plan to work, you need a trailing average long enough to totally wipe out any single-cycle signal variation … but the average needs to be short enough to have a big response to two small cycles in a row. And the single-cycle variations (max to min) are much larger than the change in average from two successive cycles … so any filter long and strong enough to entirely wipe out the big single-cycle peak-to-trough variation will hardly twitch if there happens to be two smaller cycles in a row, as happened in the Dalton minimum.
When you have run the numbers and figured out what kind of a moving average can do that, wipe out a large single-cycle signal yet not wipe out the much smaller effect of a couple of pint-sized cycles, please let me know, because I can’t think of one …
w.
Greg Goodman says:
June 25, 2014 at 9:21 pm
———————————–
When it comes to selective surfaces such as our deep transparent ocean, covering 71% of the lithosphere 4 to 5 Km deep, then watts are not watts. Frequency matters. It matters a lot.
Listening to the leaf blower? Forget it. Notice the bleating about TSI not spectral variance? Someone carries the burning shame of talking Jack Eddy down over solar variance. A shame that can never be erased in the age of the Internet. “Disingenuous” is me being polite. [snip] is closer to the mark.
And Wally? Where’s Wally now? Still stuck where he was in 2011. Still thinks that DWLWIR slows the cooling rate of liquid water that is free to evaporatively cool.
Hello Wally.
Hello down there..
Yoo hoo..
Oh Yoooo Hoooo!
Keep digging. Send us a post card from China 😉
From Willis Eschenbach on June 25, 2014 at 10:27 pm:
As I understand it, as I absorb this stuff, the reason for checking for autocorrelation is the next data tends to be similar to the last data. The near past is like the near future which is like the near past.
Thus I don’t understand why it must be trailing average. You’re invoking a chronal paradox whereas a centered average simply admits the present will likely resemble the future.
@smith
“Such conditions are seldom encountered. The radiation would necessarily have to be thermal radiation, with a spectrum that depends on Temperature.”
That would be true for all radiations. I have enough of this.
Willis says:
“in both the Maunder and the Dalton, the temperature starts rising way before that.”
“any filter long and strong enough to entirely wipe out the big single-cycle peak-to-trough variation will hardly twitch if there happens to be two smaller cycles in a row”.
My only answers tho these right now are mostly non-statistical, and without going into the data too much deeper:
–the Dalton has only two low cycles, which quite rightly shouldn’t really affect a longer term average if it doesn’t affect single 11 year cycles, except that here there were also volcanic eruptions (not your cup of tea I understand) messing things up, and also the earth was still partly ‘locked’ into the cold conditions of the Maunder. It might be easier to re- plunge the earth or self-reinforce a ‘little ice age’, if the earth hasn’t come out of a colder period for very long. (eg high ice albedo levels etc), such as going back into a generally cooler Dalton not very long after the Maunder. Again, there might be background factors here which don’t come up in a pure statistical analysis.
– background cycles which are already going on, such as changes in ocean phases (have you checked the PDO changes within the Dalton/Maunder? etc, do we have that data?-probably not-this may explain a warmer trend before the sun springs back to life)
-the data you have used in the above graphs is not accurate enough at the yearly/multi yearly scale, such as ‘Lambs winter severity index’ which is only part of a year, (although the CET is better, but this is not a world temperature).
-ultimately the weaknesses in the data (yearly accuracy, single locations such as CET rather than the whole world etc) and any background cycles, lag effects, do not allow further penetration of the solar-temperature correlation. You can only say to those who advocate a solar- temperature correlation, that they have untested assumptions about background cycles etc because data on finer scales doesn’t really match all that well; the 11 year cycle in particular barely shows up if at all, which I agree with you about.
Exactly the same sort of issues with the natural variability going on now with ‘the pause’ etc. There is turning out to be a lot of ‘background natural variability’ out there. My favourite fudge factor is ocean cycles messing things up. Cosmic rays and clouds might be another. Do they change (ie the solar wind etc) exactly in sync with solar output? I’m guessing they don’t. (And I’m guessing you are getting to your favourite theory-that it isn’t background cycles messing the solar-temperature correlation at all, nor volcanos in the Dalton, nor cosmic rays etc, but the earth’s tropical thermostat. It might be all of them together).
lsvalgaard says: June 25, 2014 at 9:42 pm
….. Jupiter shine…..
You got it doc. Now we only need to find an event with 398 day period. I can’t think of one, but have found that the IDV (IHV) has sharp and distinct peak at 17.81 Bartels (which I think comes to 480 days), any ideas why could that be?
kadaka
“our “global average” temperature is controlled by the rate of heat retention. So it is foolish to think S-B will give surface temperatures.”
S-B equation will give you the radiative forcing at TOA. Will it change surface temperature? It should. If you claim it will not. You should compute the counter forcing that will cancel it. Like Trenberth’s “the ocean is taking up X amount of heat therefore the atmosphere will not warm” That’s how to present a scientific argument. (even if we disagree with it) But all you’re saying is “it will not because it’s too complicated to compute.” It’s a philosophical conjecture.
You claim 3 errors of Eratosthenes:
“1. That Alexandria and Syene lie on the same meridian.”
Trivial. You can measure a circumference across different meridians.
“2. That the distance between Alexandria and Syene is 5000 stades.”
Not his error. It was measured by Egyptian surveyors long before Eratosthenes. I suspect the distance was accurate but the road was not a perfect straight line. A straight distance would be shorter.
“3. That the Earth is a sphere.”
It’s a good assumption. Earth is close to an oblate spheroid.
It was Carl Sagan (1980) who said Eratosthenes got a value of 40,000 km (less than 2% error). He assumed 5,000 stades = 800 km. A rare mistake by Sagan. The point is scientists in the past made fairly accurate measurements without authorizing bodies. I said enough. Goodbye.
Greg says:
June 25, 2014 at 11:20 am
Are you really too stupid to read when I write QUOTE MY WORDS IF YOU DISAGREE WITH THEM, or are you really such a big jerk as to think that they don’t apply to you?
Your claim about my position is total fantasy of your own creation. It is nothing like the views I hold.
I have said nothing at all about “definite proof” for example, that’s just your weird interpretation of my views. Even if you don’t realize these things, I’m quite clear that a) you can’t prove a negative, and b) in science nothing can be proven. As a result, I’ve said nothing about my results “proving” anything. You’re just making up a position out of the whole cloth and claiming that it’s a position that I hold. Sorry, not buying it.
QUOTE WHAT I SAID.
Regarding the 11-year signal in the climate, what I’ve said is that there are a lot of people out there that believe that such a signal exists, but that despite lots of looking, I’ve never seen it. So I’ve asked adherents of the theory where the best evidence is, and I’ve look at that evidence, and I’ve still never seen it.
I have made no effort, and in fact I’ve deliberately refrained, from making the kind of further conclusions that you list above. I have NOT said that the sun has no influence on the climate, for example. I have NOT said that the lack of the 11-year cycle proves anything about the solar influence.
What I’ve said is that I can’t find the 11-year signal. I also can’t find the Gleissberg cycle, either in the sun or in terrestrial datasets. In addition, I can’t find the cooling that allegedly accompanies the Dalton and Maunder minimums.
The only conclusion that I’ve drawn from all of that is that those facts support my hypothesis that the earth has a thermostat. It’s not strong evidence, there may be other reasons, but the observations certainly support my hypothesis as a possible explanation.
And that’s all that I’ve said. The further conclusions that one might draw from those facts, Greg, I leave to you … although given the hash you’ve made of assessing my position, I probably should leave them to someone else …
w.
toto
“The bottom line is that the sun’s output is remarkably constant.”
It amazes me when laymen and even scientists say this because the earliest direct measurement of solar irradiance was in 1838 by Pouillet and he got a lower value than today. The belief that solar irradiance must be constant is very strong that we would rather disregard Pouillet and look for proxy data that confirm what we believe. It would be more honest to say we don’t know because nobody measured it before Pouillet.
BTW the 1 W/m^2 observed variance in solar constant translates to 0.25 W/m^2 change in irradiance. It can melt 1 inch of ice over a year. Sea ice is about 72 inch thick. Sea ice could disappear in 72 years with that small solar variance. What if it’s a negative variance? Remove that much heat for 100 years (1600-1700) and you will see sea ice and glaciers grow. You will see a little ice age in the Arctic region and Northern Europe. The River Thames in London will freeze on winters. Haven’t we seen that before?
Ohooo…
Too difficult? Too harsh?
I play a long game. Ten years. Screen shots for every post.
But trust me. Anthony is A-OK. However Wally and the leaf blower might be under the bus….
But then, who cares about those squealing bitches?
Willis says:
June 23, 2014 at 3:55 pm
“…..
Eliza says:
June 23, 2014 at 3:34 pm
CET shows nothing there’s not even a slight trend if you include latest data 2014http://www.climate4you.com/CentralEnglandTemperatureSince1659.htm
Say what? Each of those three datasets has a definite trend.
w.
……”
The CET summer trend is definitively not significant at 2 sigma level , and the winter trend is maybe just barely hanging in or on the verge of falling out of the 95% CI, though the annual trend can probably be said to be within statistically significant. limits at the 95% level.
( and nota bene all three have a lousy explanatory factor {r²} ). So no Willis , there is not a definitive trend in ALL three datasets, at least not in the strictly statistical sense.
But that said, its a minor quibble in my mind , because the CET time series just like the rest of the surface datasets most toted ,unfortunately do not satisfy the assumptions necessary for a valid least squares analysis to be anything but a very corse grained flat low resolution black and white snapshot of a many faceted and multicolored , multidimensional thingy.
For all participants, including the moderator magazine WUWT.
All the discussion so far and from now on, refer only to the conclusion phenomenon in so far as science is able to vividly convey to the stakeholders. But the real causes of phenomena have their origins hidden to be discovered, as well as some kind of strange disease. The doctor can not determine the correct diagnosis on the basis of the patient’s temperature. Who determines easier dijagnose, a doctor or a vet? Animals do not know tell me how you feel. Even with this consideration should enter the “interior” of the system, and to the solar system. You need to know who is the one who causes sunspots, their cycle and intensity.
Here, on this occasion, I give you a suggestion throughout this forum: to form a team of experts who will link up with strong institutions and governments of America, to make a deal for deciphering the true causes of the appearance of the sun, and with it the sunspot and a lot more.
It is certain that these and all participants will spend a third of the sum of 21.4 billion dollars and will get solutions for all time. Surest proof, set in the past, when something important happened and based on the budget transfer in the future. My evidence shows that the cycles of various phenomena “scattered” in time (past, future and present are), with different amounts of time and intensity, but all within the laws by which this happens. We’ll see how many people will be interested to solve this problem. It’s go time there.
Willis Eschenbach says:
“Like I said, until you have evidence of the effect, speculation about possible mechanisms is very premature.”
I would not be discussing it if I had not seen evidence for it in the observations in the first place. If anything is premature, it is your assumptions about solar forcing, page 15:
http://virtualacademia.com/pdf/cli267_293.pdf
http://www.woodfortrees.org/plot/esrl-amo/every:13/normalise/plot/sidc-ssn/from:1850/scale:0.5/normalise
Lester Via says:
“He also explained, adequately I thought, why that data didn’t provide much proof of causation.”
He said:
“As you can see, there is very little support for the “solar minima cause cool temperatures” hypothesis in the CET.”
Yet the three coldest periods in CET are ALL during solar minima, so clearly he is talking nonsense.
[snip . . maybe you have had a long day. . mod]
What explanations exist for the extremely abrupt temperature drops during the last glaciation?
http://iceagenow.info/wp-content/uploads/2011/06/Easterbrook-Natural_global_warming.jpg
Probable Explanation: For a period of years a minima of Solar Rads reached Earth.
Several generalized explanations of declines in Rads include:
A) The Sun’s radiation strength declines
B) Solar radiation is blocked from reaching Earth
One known culprit for B is volcanic ejecta.
What explanations exist for the extremely abrupt temperature drops during the last glaciation?
http://iceagenow.info/wp-content/uploads/2011/06/Easterbrook-Natural_global_warming.jpg
Greg says:”… Willis seems to be digging his heels in on the presence of not of a statistically significant 11y solar signal as definite proof of whether there is a solar influence. I think that is a mistake.”
Willis says: “Are you really too stupid to read when I write QUOTE MY WORDS IF YOU DISAGREE WITH THEM, or are you really such a big jerk as to think that they don’t apply to you?
Your claim about my position is total fantasy of your own creation. It is nothing like the views I hold.
…
I have NOT said that the lack of the 11-year cycle proves anything about the solar influence.”
Easy on the insults big fella. I’m not going to go trawling the last six months of your threads here on WUWT for a precise quote.
If that is now your stated position, fine, I’ll bookmark this page.
You suggested above someone run a trailing running mean. Hang on I supposed I’d better quote you before you start shouting again….
“Try this. Put a running average of some kind on the sunspot data. Of course it has to be a trailing average, since otherwise the future affects the present.”
Now I know you’re not a fan of running means, so I’m guessing that was just to make it easy to do. Why you want him to introduce frequency dependent phase shift is a bit odd, do you now think you need to lag the result of a gaussian filter as well?
In any case, one case where you will not centre the data is when applying a exponentially decaying weighting to simulate a relaxation response. This is also a convolution. This does add a delay, as you have shown in the past, one that is physically meaningful, determined by the response time of the system.
Implementation here:
http://climategrog.wordpress.com/2013/03/03/scripts/
This gives the graph I’ve posted already
http://climategrog.wordpress.com/?attachment_id=981
Now we’ve already seen that there are other signals that perturb the 11y cycle, it is not the sole driver of climate. However, that longer term trend seems a remarkably good match across most of the record.
You dived in to lambaste me not quoting you but so far you’ve avoided commenting on what I’ve shown in response to your call for people to post what they think may indicate a solar signal.
” The only conclusion that I’ve drawn from all of that is that those facts support my hypothesis that the earth has a thermostat. It’s not strong evidence, there may be other reasons, but the observations certainly support my hypothesis as a possible explanation.”
As I have repeatedly said, I think you have pointed out a key fact about tropical climate. It is remarkably stable and to a large degree probably for the reasons you suggest.
However, this applies less strictly to extra-tropical zones that do not have the same climate. They are more sensitive as I showed in detail with my volcano stack plots. So I think it would be over-doing it to suggest total thermal regulation, temperatures do change. In that graph I show how that may coincide with variations in SSN.
That would seem to be the sort of thing you have been searching high and low for, so it is odd you chose to ignore it. Perhaps you just missed it , so I’ll provide it again along with a possible explanation of how this is compatible with your hypothesis:
“The penetration depth of UV could explain how a long term signal circumvents the tropical surface feedbacks of which we are both so fond.”
Salvatore Del Prete
Observed increase in ozone in the region of the South Pole.
http://www.cpc.ncep.noaa.gov/products/stratosphere/strat_a_f/gif_files/gfs_t50_sh_f00.gif
thingadonta says:
“-ultimately the weaknesses in the data (yearly accuracy, single locations such as CET rather than the whole world etc) and any background cycles, lag effects, do not allow further penetration of the solar-temperature correlation”
Nothing can characterise Maunder and Dalton better than the negative NAO episodes during each of the monthly-seasonal cold hits in the regions known to have been effected by LIA weather.
Here we are in a weak solar cycle, and CET has already fallen 0.6°C due to an increase in negative NAO conditions. And it will follow the same pattern as Gleisberg and Dalton and get much colder again from just after SC24 maximum through to around SC25 maximum. Given that this will promote a return to warm AMO between SC24&25 maximums, and initially stronger El Nino (i.e. negative NAO = weaker trade winds), I don’t think that global mean temp’s is a good measure.
Sounds good Ulric, can you post some data support that rough outline.
” I don’t think that global mean temp’s is a good measure.” Are you saying that you don’t think there is a global impact because of induced climate variations? If I’m reading you correctly you are saying there feedbacks which keep temps constant.
may be short term that could explain the attenuation of 11y signal. Long term there are changes that appear to follow SSN.
http://climategrog.wordpress.com/?attachment_id=981
vukcevic says:
June 26, 2014 at 12:59 am
but have found that the IDV (IHV) has sharp and distinct peak at 17.81 Bartels
There are no such peaks in either IDV or IHV. The only significant large peaks are at 10.4 yrs and 11.0 yrs, respectively. In addition, IHV has a very sharp peak at 0.5 yrs because of the well-known semiannual variation.
According to the Temperature Chart the 1950’s were a fraction of a degree different than the Dalton minimum. We know the Thames froze over during that time period and not in the 1950’s.
IMO your temperature graph is incorrect as are most that scientists use today.
Ex. In April, the temperature when the sun sets in NYC is a full 10 degrees warmer than the temperature on Long Island. I’ve personally measured this many times. What does NOAA or most scientists say the temperature difference is due to UHI?
The temperature graphs are wrong and we need to look at the big picture which shows that the Sun spot count and the temp are closely related.
Greg Goodman says:
“” I don’t think that global mean temp’s is a good measure.” Are you saying that you don’t think there is a global impact because of induced climate variations? If I’m reading you correctly you are saying there feedbacks which keep temps constant.”
I’m saying that initially the global impact to a short term drop in solar forcing, is a temperature rise, due to El Nino and a warm AMO functioning as negative feedbacks, with considerable overshoot. Both have a negative effect on upper OHC and so result in longer term cooling of global mean surface temp’s. The corollary of that is when stronger solar forcing resumes, it results in a short term drop in global temperature due to La Nina and a cooler AMO, fueling longer term global mean temp rise by recharging of the upper OHC.
“may be short term that could explain the attenuation of 11y signal.”
I think these phase shifts in the response to solar cycles need to be taken into account:
http://wattsupwiththat.com/2014/06/23/maunder-and-dalton-sunspot-minima/#comment-1669182
Toto You quoted an earlier comment I made .giving a link. to one of Leif’s presentations. I had inadvertently posted the wrong link. A corrected post follows.
“The 10:30 AM post should read
“Leif – checked your link http://arxiv.org/ftp/arxiv/papers/1004/1004.2675.pdf
“
Heres quote I would cherry pick -( I especially like Fig 5 )
“One does notice a certain “regularity” in the 10Be ice core variations, however. In Figure 5 we show as blue lines, the envelope of the “minima” in the 10Be cyclic intensity variations.
This “envelope” has long term periodic maxima occurring at ~1685, 1815 and 1895 A.D. This
type of variation could possibly be related to long term 10Be production changes. Indeed 22 year
averages (filters) of the 10Be concentration, which smooth out the shorter term cyclic variations,
show broad maxima at approximately these times (McCracken, et al., 2004). These times also,
more or less, coincide with the times of maxima of 14C concentration in tree rings”
On this basis just connect the minima of the HMF on page 11 at
http://wattsupwiththat.com/2014/06/23/maunder-and-dalton-sunspot-minima/#comment-1669289
to see the recent solar grand maximum and the Dalton and Maunder Minima very nicely displayed. I’m happy to cherry pick your slide here.
http://www.woodfortrees.org/plot/esrl-amo/every:13/normalise/plot/sidc-ssn/from:1850/scale:0.5/normalise
There is see some periods in-phase some out of phase. Maybe with red/green 3D glasses they line up better 😉