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
“Thus it seems most likely you are either lazy, or trying to prevent the closer scrutiny of your “fit” that might result from only using the relevant SSN data for that size graph. Both together is a possibility.”
Listen kakada, if you can avoid being pissy and just ask for what it is you think should be bigger or whatever it would be more productive. I can produce a SVG image if you can suggest somewhere to drop it, then you can zoom in to your heart’s content.
I showed the full length of SSN data to demonstrate the long term rise which was half the point and scaled the two to fit SST to it. Your suggested motives are just because you are feeling bitchy, nothing to do with why I scaled the graph that way.
Now if you’d like a close a look a some part just say what you want so that I don’t get all lazy and produce something else not to you taste. Or suggest where I can drop you ans SVG file, wordpress won’t take them.
For the record, I scaled the relaxation calculation by 1/90 to match the SST variability.
vukcevic says:
June 26, 2014 at 11:36 am
I understand and accept your point, but what I found in number of data files (from various geomagnetic related records is ~ 27.851 days). I will also look at the Kyoto dst data, one year of daily numbers should be suffice.
What you find by mixing oranges and apples is some artificial period which is about the average of 27 and 28.5 days. One year of data is never enough.
Regarding the reconstruction attempts and the seemingly incongruent nature of different proxies, I have some thoughts. This is especially the case for warming and cooling periods and could be what is causing such a spread in these reconstructions.
Re: Oceanic/atmospheric teleconnected systems and their warming/cooling patterns. We have seen that the globe responds to these teleconnections in patterns, IE some areas are warmer and some are colder, and some are dryer and some are wetter. We know this pretty well about El Nino/La Nina and the Arctic Oscillation. Other large systems have their unique pattern of temperature/weather pattern variations. In addition, when oceanic/atmospheric teleconnected systems are not in phase with each other one kind of pattern develops. When they are in phase, another kind of pattern develops. The point is that if you pick a proxy from the warm location of the pattern, your cooling will not show up. But that is not to say that warming in that location is evidence against a cooling period. It could be part of the expected pattern. So I don’t get my knickers in a twist over incongruent reconstructions. That’s why I like the cream to dark brown combined reconstruction referred to in an earlier link I provided. That spread may indeed be showing us an oceanic/atmospheric teleconnected “pattern” or set of patterns that would help us understand why it got colder/warmer.
“The discovery paper is here http://www.leif.org/research/Long-term%20Evolution%20of%20Solar%20Sector%20Structure.pdf see in particular Figure 5. The data since the 1970s fully confirms this picture.”
Thanks I read that later.
It looks like sturgishooper has taken his ball and gone home wrt to the Socratic Method we started on. I interpret that as meaning that he has seen the light and no longer object to my reconstruction. Good for him.
Greg Goodman says:
June 26, 2014 at 11:48 am
“The data since the 1970s fully confirms this picture.”
Thanks I read that later.
A modern update is here: http://www.leif.org/research/Solar%20Sector%20Structure.pdf
[from a seminar I gave At Lockheed-Martin].
Willis Eschenbach says:
June 26, 2014 at 10:44 am (replying to)
Thanks, RA, but I’m not following you. What kadaka said is that the energy that is not reflected is absorbed … if that is not true, as you say, then where is it going? I mean, if it’s not reflected and it’s not absorbed, where is it?
You are correct – but only for an isolated body in a perfect infinite vacuum inside a perfect black body. The S-B equation cannot be used for a body of real-world ice floating in a real-world ocean at a real-world latitude radiated by a real-world sun beneath a real-world atmosphere transmitting only a portion of a annually-varying solar radiation that varies day-by-day.
Heat transfer is always instantaneous: The amount of long-wave radiation emitted at any given point int time is dependent on the instantaneous surface temperature, the actual emissivity at that temperature, and the area emitting (the local geometry immediately above the surface). The long-wave energy absorbed is proportional to the albedo at that received radiation frequency, the angle of emission/absorption direction of the ray coming into that surface, the temperature (energy) of the body emitting the received radiation, etc. The rest of the energy absorbed can be evaporated out, conducted out, convected away (by air AND by water), sublimated away (if the ice is topside), conducted to/from the iceberg interior, or increased by the condensation of excess humidity above the surface onto the surface. Fortunately, or unfortunately, depending on how you look at it, the various energy transfers can (and always do!) go on at the same time in different directions. Thermal equilibrium is rarely – if ever! – actually achieved in the real world.
RACookPE1978 says:
June 26, 2014 at 11:55 am
Thermal equilibrium is rarely – if ever! – actually achieved in the real world.
The question is not if the equation and assumptions are strictly correct, but if they are good enough for the purpose [which I think they are – show me with experimental data if I am wrong ]
lsvalgaard says:
===
Greg Goodman says:
June 26, 2014 at 10:04 am
And if we apply a relatively short relaxation response to SSN what do we see
Apart from this falling apart the last 30-40 years, the rest could just be a circular reasoning as you pick a relaxation response to produce the fit.
===
Why is that circular? Yes I did an approximate fitting of the time-constant variable to demonstrate that a relaxation to a SSN induced change could produce something close to long term SST variability. That’s not circular..
Neither does it “fall apart”. There is a progessive divergence near the end of a long record. I did not hide , crop it off of blend in a thermometer record, I drew attention to it. I estimate it diverges from about 1988-1990.
Now raises the question why surface temps are running flat when SSN is dropping. Either it’s totally unrelated or there’s another factor(s) at a play. Seems a bit late for AGW but maybe it could brought in somewhere, or maybe there is anther reason for extra net TOA energy since that time , like: 1.8 W/m2 of extra SW:
http://climategrog.wordpress.com/?attachment_id=955
http://climategrog.files.wordpress.com/2014/04/tropical-feedback_resp_ci.png?w=843
lsvalgaard,
“Put your money where your mouth is, I will bet you 200 dollars US that in ten years TSI will be at least 1 watt/Square Meter below the last minimum.
I hope I live long enough to collect.”
I hope we both do so I can collect, either PMOD is wrong or you’re contention that SSN can be directly translated to TSI is wrong, which is probably correct.
http://www.woodfortrees.org/plot/pmod/from:1980/mean:12/normalise/plot/sidc-ssn/from:1980/mean:12/normalise
climatereason says:
June 26, 2014 at 10:52 am
I read only far enough to check the quote. It’s always the first thing I do, to make sure the person is quoting me correctly, and that they are responding to something I said to them, and that the quote is not taken out of context.
But when I checked the quote, I saw that I hadn’t been responding to some new person posting as “climatereason”, I’d been responding to “tonyb”.
At that point I stopped reading, since obviously there had been some major confusion, and I don’t have time for reading confused threads. I noted the problem in my comment, and then moved on to the next comment … but as you say …
… at which point, of course, I noticed the signature at the bottom of the comment. However, it was NOT “[your] name clearly at the bottom”, as you fatuously claim.
It was just your other alias.
And since I’d already been fooled by that other alias, I realized that I’d been fooled again, and responded in my comment.
Oh, I see. It’s my fault. It has nothing to do with the fact that you are using two aliases. It’s because I’m “easily confused”.
Finally, I never responded to your “offer” because I never read your “offer”. When someone is screwing me around by using two aliases, I fear their comment goes unread. And now you’ve come back, told me I’m “easily confused”, claimed I’m being unresponsive to whatever your “offer” might be, and once again, you’re “out of here” … like it’s all my fault.
As I said quite clearly in my response, Tony …
So your claim that I’m being unresponsive and I’ve gone off on a tangent is simply not true. I have overlooked the fact that I’ve been fooled twice by your aliases, and said that if you post under your own name I’m happy to respond and discuss these issues with you. And I am.
However, blaming the fact that you are posting under two different aliases on some fault in WordPress or blaming it on your iPad won’t cut it. If you aren’t smart enough to figure out how to post as “Tony Brown”, I’m not interested. Seriously. I’ve told you I’ll discuss things with you if you post under your own name. I’m done with trying to guess what your new alias might be.
Look, Tony, I’m not happy that this has gone all pear-shaped, but truly, I don’t even make any attempt to connect an alias with a real person, or even more so, with another alias. Not enough hours in the day. I had no idea that tonyb was Tony Brown, and even less idea that “climaterealists” or “climatereason” or whatever your other alias is was actually tonyb who is actually Tony Brown. Other people’s worlds don’t revolve around you, my friend.
So I repeat my offer. Post as Tony Brown and I’m happy to discuss the science. Post as climatereason or tonyb, and you’re talking to the hand …
w.
Sure – Easy example, though as always, an incomplete example.
Essentially “all” thermal energy received on earth (as a sphere) is received as IR radiation from the sun, but – as you confirmed several months ago, the solar energy received at TOA (top of atmosphere) as a good approximation of day-of-year (DOY) is:
TOA (DOY) = TSI_average_year) x (1+ cos (DOY-3)/365)
So it TOA = a varying amount varies between 1310 watts/m^2 (early July) up to 1410 watts/m^2 in Jan 3.
Northern hemisphere radiation varies even more – maximizing in summer this week (the solstice) and minimizing in late December. But, actual NH temperatures peak 4-6 weeks later in late July-first of August. NOT at the peak of radiation, and NOT at the highest solar elevation angles or length of day. Coldest NH days are after the peak of solar TOA AND 2 months AFTER the minimum solar elevation angle.
Since longwave radiation emitted is a function of actual instantaneous temperature of the emitting surface, emitted radiation is of course immediately proportional to the thermal energy (temperature) (Tkelvin)^4 .
From this, emitted radiation is NEVER equal at ANY time of year to received radiation. In EVERY case – even at the whole-earth level on a total-over-the-average-day level, you have to include thermal lag and thermal transfer (hot areas to cold areas) to get a total heat transfer. And the “hot areas (because they are eventually radiating to a near-perfect space at 0.3 K) will always dominate the longwave radiation loss total.
For example, an open ocean Arctic at 4 degrees C radiates to a cloudy atmosphere at -30 degrees C. How much less energy is lost by radiation from a ice-covered arctic at -20 degrees C?
Look at ice areas for a different thermal “un-equilibrium” example: Maximum arctic sea ice extents are the first 2 weeks in April – well AFTER even the coldest days of the year, well after the minimum solar elevation angle/length of day, but getting towards the peak of the NH radiation. Antarctic sea ice maximums are late October, also as the Antarctic olar exposure increases AND as the SH summer approaches. Antarctic sea ice minimums are late February – which doesn’t ANY of the other peaks nor troughs.
RACookPE1978 says:
June 26, 2014 at 11:55 am
Thanks, RA, that’s all quite interesting, but you haven’t answered my question. Kadaka stated mathematically that the solar energy that is not reflected is absorbed.
You said no, you disagreed.
So I asked … IF (as you say) the solar energy is neither reflected nor absorbed … then where is it?
That’s what you didn’t answer. It has nothing to do with the S-B equation, by the way. It’s a simple question.
Regards,
w.
Phrasing it to those terms:
Solar energy in => IR + UV energy absorbed (heating the air or dust + clouds or land or water or ice or plants => that later cool off and heat something else) + latent and sensible heat changes + LW radiation losses to the atmosphere (that later re-radiate or radiate to space) .
Heat absorbed does go into those temperature and state-of-matter changes and thermal delays.
Leif Check Fig1 at
http://www.leif.org/research/Goelzer-Comment-with-Suppl.pdf
Join the minima on your red curve . Note 20th century rise in solar activity from 1902-45.decline 1945-67 rise from there to 20th century solar max plateau 80 – 90. Then of course sharp fall to 2010.
This fits nicely the Berggren Dye 3 20th century 10 Be flux data and Hadcrut temps. Even the 1945 -60 decline is seen.
I note the difference between you and other investigators especialy pre 1910. and need more time to investigate.
Do you think recent sharp fall presages global cooling in the near term?
“A modern update is here: http://www.leif.org/research/Solar%20Sector%20Structure.pdf
[from a seminar I gave At Lockheed-Martin].”
Thanks again the looks very interesting. Is the polarity data that was used to create that FFT power spectrum archived anywhere. I’d be very interested to in having a closer look at some aspects of that.
Greg Goodman says:
June 26, 2014 at 12:06 pm
Why is that circular? Yes I did an approximate fitting of the time-constant variable to demonstrate that a relaxation to a SSN induced change could produce something close to long term SST variability.
That is circular because you say: see the SST and the SSN match, but the variable was chosen to make them match.
I estimate it diverges from about 1988-1990.
That is the correlation falling apart.
Greg Goodman says:
June 26, 2014 at 12:42 pm
Thanks again the looks very interesting. Is the polarity data that was used to create that FFT power spectrum archived anywhere. I’d be very interested to in having a closer look at some aspects of that.
You can find the polarity data 1926-present here: http://www.leif.org/research/spolar.txt
The data is year, month, day, Bartels rotation nr., 27 X and ‘.” symbols, one for each day. X is polarity into the Sun. ‘.” away from the Sun.
lsvalgaard says:
What you find by mixing oranges and apples is some artificial period which is about the average of 27 and 28.5 days.
The rotation rate of the corona [which is what controls the HMF period at Earth] is a mixture of the Bartels rotation rate and another system rotating at 28.5 days so your 27.851 days is not a physical entity
The Bartels rotation rate (27 days) probably refers to a persistent structure in the deeper layers
It does not have a distinct name. 28.5 days is close enough. For what it is worth, it is also the rotation period of the radiative inner core [which has rigid rotation a bit slower that the differentially rotating outer layers].
………..
BINGO. “The rotation rate of the corona”. Coronal Mass Ejections (CMEs) !
Thanks.
It is likely that either a) 27 days or b) 28.5 days are not exact physical numbers, so 27.851 is (a+b)/2. 27 days may be the more likely candidate for obvious reason, error of 0.7%, i.e. 27.2 would do nicely, alternatively 28.7 or any other combination is just as welcome.
From my point of view, the actual rotation number is not so critical, it is what what may have an effect and detected and recorded in the data.
Thanks, you just resolved a two year long dilemma.
so much for the speed of light
http://phys.org/news/2014-06-physicist-slower-thought.html
Dr Norman Page says:
June 26, 2014 at 12:41 pm
Note 20th century rise in solar activity from 1902-45.decline 1945-67 rise from there to 20th century solar max plateau 80 – 90. Then of course sharp fall to 2010.
Note the 19th century rise in solar activity from 1901-1850 going back in time.
This fits nicely the Berggren Dye 3 20th century 10 Be flux data and Hadcrut temps. Even the 1945-60 decline is seen.
If you quantify your statement you’ll se that it does not fit at all.
I note the difference between you and other investigators especialy pre 1910. and need more time to investigate.
Yes, the purpose of the note is to point out that they are very wrong. Good that you caught that.
Do you think recent sharp fall presages global cooling in the near term?
No, why would it? And you are not precise. Global cooling by 0.0001 degrees, 0.01 degrees, 1 degree, 10 degrees, etc. Which one?
According to the Svensmark hypothesis, Cosmic rays are the mediator connecting solar activity with climate. But there is the implicit assumption that cosmic rays from outside the solar system are constant. Suppose that as the activity of the sun changes the magnitude of cosmic rays entering the solar system changes and that climate is a function including both solar activity and cosmic ray input.
Willis Eschenbach says:
June 25, 2014 at 7:54 pm
Yet again you step in it. Thanks at least for replying, however. Now that I’ve played your game, how about you’re returning the favor & looking at another paper?
Now the one I ask you to consider is Meehl, et al, to include all the studies it cites finding the 11 year signal.
If you yet again refuse, then we’ll know for sure that you’re intentionally dodging. That’s the “one” study I now ask that you review, or else be known as a dodger.
Charles Tossy says:
June 26, 2014 at 1:26 pm
Cosmoclimatology doesn’t presume that GCR flux is constant. Quite the contrary.
Please see Nir Shaviv’s explanation for the fairly regular occurrence of Icehouse intervals on earth, based upon spiral-arm passages.
http://astrogeo.oxfordjournals.org/content/48/1/1.18.full
vukcevic says:
June 26, 2014 at 1:00 pm
From my point of view, the actual rotation number is not so critical, it is what what may have an effect and detected and recorded in the data. Thanks, you just resolved a two year long dilemma.
Well, there is not one rotation rate. Your analysis, if it is any good, should have picked up three rates: 26.8, 27.2, and 28.5. It did not, so …
Charles Tossy says:
June 26, 2014 at 1:26 pm
According to the Svensmark hypothesis, Cosmic rays are the mediator connecting solar activity with climate. But there is the implicit assumption that cosmic rays from outside the solar system are constant.
And on the time scale of hundreds of years the cosmic ray intensity is constant. But the Svensmark hypothesis does not hold water, i.e. is not supported by the data, as the cosmic ray intensity measured in the Earth’s atmosphere does not vary as the temperature.
‘milodonharlani”
“Now the one I ask you to consider is Meehl, et al, to include all the studies it cites finding the 11 year signal.
I can do better than that!
Willis The one study I ask you to look at is the study I just did.
google “sun LIA”
That study contains all the references.
milodon.
RECALL THE REQUEST
“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?”
TEMPERATURE EVIDENCE.
go ahead.
you know what temperature is.
please point to the data.
not a paper that points in a thousand different directions. but temperature evidence.