This is interesting. A quick cooling in Europe together with an increase in humidity and particularly in windiness was found to coincide with a long-term reduction in solar activity 2800 years ago during something called the “Homeric minimum”.
The paper published in Nature Geoscience suggests that solar grand minima was the trigger for cooling of the climate in Europe. Approximately 2800 years ago, one of these Grand Solar Minima, the Homeric Minimum, caused a distinct climatic change in less than a decade in Western Europe. While they talk about UV, the forcing mechanisms still are unclear but the evidence in this paper suggests that solar effects are significant. Dr. Leif Svalgaard sent me the notice of the paper, and included this graph which he says:
Attached is one of the better reconstruction of solar activity.
There are, of course, several other excursions not mentioned, e.g. the more severe one around 650 AD

Here’s the abstract, bold mine:
Regional atmospheric circulation shifts induced by a grand solar minimum
by Celia Martin-Puertas, Katja Matthes, Achim Brauer, Raimund Muscheler, Felicitas Hansen, Christof Petrick, Ala Aldahan, Göran Possnert & Bas van Geel
Nature Geoscience (2012) doi:10.1038/ngeo1460
Large changes in solar ultraviolet radiation can indirectly affect climate1 by inducing atmospheric changes. Specifically, it has been suggested that centennial-scale climate variability during the Holocene epoch was controlled by the Sun2, 3. However, the amplitude of solar forcing is small when compared with the climatic effects and, without reliable data sets, it is unclear which feedback mechanisms could have amplified the forcing. Here we analyse annually laminated sediments of Lake Meerfelder Maar, Germany, to derive variations in wind strength and the rate of 10Be accumulation, a proxy for solar activity, from 3,300 to 2,000 years before present. We find a sharp increase in windiness and cosmogenic 10Be deposition 2,759 ± 39 varve years before present and a reduction in both entities 199 ± 9 annual layers later. We infer that the atmospheric circulation reacted abruptly and in phase with the solar minimum. A shift in atmospheric circulation in response to changes in solar activity is broadly consistent with atmospheric circulation patterns in long-term climate model simulations, and in reanalysis data that assimilate observations from recent solar minima into a climate model. We conclude that changes in atmospheric circulation amplified the solar signal and caused abrupt climate change about 2,800 years ago, coincident with a grand solar minimum.
UPDATE: Here’s the press release from the Helmholtz Association of German Research Centres.
Climatic effects of a solar minimum
A grand solar minimum and the climate response recorded for the first time in the same climate archive highlights the need for a more differentiated approach to solar radiation
An abrupt cooling in Europe together with an increase in humidity and particularly in windiness coincided with a sustained reduction in solar activity 2800 years ago. Scientists from the German Research Centre for Geosciences GFZ in collaboration with Swedish and Dutch colleagues provide evidence for a direct solar-climate linkage on centennial timescales. Using the most modern methodological approach, they analysed sediments from Lake Meerfelder Maar, a maar lake in the Eifel/Germany, to determine annual variations in climate proxies and solar activity.
The study published online this week in Nature Geosience (06/05/2012) reports the climatic change that occurred at the beginning of the pre-Roman Iron Age and demonstrates that especially the so-called Grand Minima of solar activity can affect climate conditions in western Europe through changes in regional atmospheric circulation pattern. Around 2800 years ago, one of these Grand Solar Minima, the Homeric Minimum, caused a distinct climatic change in less than a decade in Western Europe.
The exceptional seasonally laminated sediments from the studied maar lake allow a precise dating even of short-term climate changes. The results show for a 200 year long period strongly increased springtime winds during a period of cool and wet climate in Europe. In combination with model studies they suggest a mechanism that can explain the relation between a weak sun and climate change. “The change and strengthening of the tropospheric wind systems likely is related to stratospheric processes which in turn are affected by the ultraviolet radiation” explains Achim Brauer (GFZ), the initiator of the study. “This complex chain of processes thus acts as a positive feedback mechanism that could explain why assumingly too small variations in solar activity have caused regional climate changes.”
Albeit those findings cannot be directly transferred to future projections because the current climate is additionally affected by anthropogenic forcing, they provide clear evidence for still poorly understood aspects of the climate system, emphasizes Achim Brauer. In particular, further investigations are required with a focus on the climatic consequences of changes in different wavelengths of the solar spectrum. Only when the mechanisms of solar-climate links are better understood a reliable estimate of the potential effects of the next Grand solar minimum in a world of anthropogenic climate change will be possible. In this respect, well-dated annually laminated lake sediments are also in future of crucial importance for these studies.
Therefore, scientists from the German Research Centre for Geosciences (GFZ) and other institutions search for such archives around the world in order to to obtain a more accurate approach to the solar-climate relationship and the different regional responses.
Celia Martin-Puertas, Katja Matthes, Achim Brauer, Raimund Muscheler, Felicitas Hansen, Christof Petrick, Ala Aldahan, Göran Possnert and Bas van Geel: “Regional atmospheric circulation shifts induced by a grand solar minimum”, Nature Geoscience, DOI 10.1038/NGEO1460
Pictures of Eifel maar lakes and drilling can be found here:
http://www.gfz-potsdam.de/portal/gfz/Public+Relations/M40-Bildarchiv/Bildergalerie+Klimaforschung
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“The effect on the globally averaged energy balance is much smaller.”
Agreed that the effect is larger as one progresses from equator to pole and the large sea area in the southern hemisphere reduces the impact there.
However more meridional or equatorward jets give increased cloudiness (not as per Svenmark) due to the longer lines of air mass mixing around the globe and that causes reduced solar shortwave into the oceans for an effect on ocean heat content and the globally averaged energy balance over enough time.
As regards CO2 the thing is that if solar inactivity causes cooling then the earlier high solar activity would probably have been enough to cause the observed warming without any significant contribution from CO2.
Anyway, this isn’t a new finding merely a consolidation of phenomena accepted in principle by Michael Mann and Gavin Schmidt (and others since) a while ago as here:
http://climaterealists.com/index.php?id=7758
“How Gavin Schmidt and Michael Mann almost got it right in 2001”
A pity for all of us that they didn’t follow through and instead just defaulted to the faulty CO2 paradigm.
Meanwhile, all credit to Leif for highlighting this even though he doesn’t agree with the solar / climate implications.
UV penetrates deepest into ice and water. Even at the point in depth where there is no visible light from the sun, there is still UV. I believe, and this is just my own personal belief, that changes in UV light have a significant impact on both ocean energy content and the melting of ice.
by Celia Martin-Puertas, Katja Matthes, Achim Brauer, Raimund Muscheler, Felicitas Hansen, Christof Petrick, Ala Aldahan, Göran Possnert & Bas van Geel
Any relation to James? Enquiring minds need to know.
Stephen Wilde says:
May 7, 2012 at 9:53 am
“Henry, it seems that high solar activity with its associated particle and wavelength changes reduces ozone above 45 km to cause a cooling mesosphere and stratosphere DESPITE more ozone below 45km.”
Stephen, you’re confusing me. I thought high solar activity means more UV as a fraction of TSl which means more ozone and more heating of the stratosphere. This makes sense to me as an amplifying mechanism for TSI. At solar max you have the normal surface heating somewhat diminished plus augmented stratospheric heating, making a push-pull effect on convective circulation, that is, more upward convection at the equator and more meridionial circulation at high altitudes. This produces a temperature inversion at the poles and the northward jet stream shifts you often talk about. Anyway, thats the mental image I have of UV effects (which may change tomorrow).
Stephen Wilde says
http://wattsupwiththat.com/2012/05/07/solar-grand-minima-linked-to-cooling-period-in-europe/#comment-978669
Henry says
if we want to know for sure,
we have to measure it…???
it seems to me many people underestimate the power of ozone
on its own (at very low concentrations it deflects at least 15-20% of all incoming sunlight,
so if there is more or less it will have a marked influence on that percentage…
Jan P. Perlwitz says:
May 7, 2012 at 9:48 am
Two notes:
1) This paper concludes “We conclude that changes in atmospheric circulation amplified the solar signal and caused abrupt climate change about 2,800 years ago, coincident with a grand solar minimum.” Given that we may be heading into a grand solar minimum, that’s one of the reasons why it’ll be interesting watching what happens in the next couple of decades.
2) Anthony used to report the monthly figures from GISS, but abandoned them after discovering all the shanigans they do with past data. (Hey, I remember a hot day in the drought of the late 1960s. Oh, you mean it wasn’t that hot? Excuse me!) The “hottest year” crap is so tied up with noisy data under the best of circumstances, it’s not worth getting to worked up about. “Hottest decade” is more interesting, as is the plateau it may be showing.
I see this more as an indicator that solar activity in records such as this and the “pause” in global warming for the past 15 years suggests that people who call GHGs the dominant driver since the late 1970s’ PDO flip may be in for a surprise. In the meantime, it’ll be interesting watching what happens in the next couple of decades. At any rate, this paper is not about dominant drivers, it’s about solar activity and an interesting correlation.
I do agree that some people here overreact to most of the papers that come through here. Most are little steps, and the important ones will be found to be important years from now. Chill out and enjoy the trip.
Yes, and no. It is my understanding that while 2010 was the highest if you average the entire year on an annual basis, the highest temperatures reached during 2010 never exceeded 1998. 1998 had a shorter, higher peak than 2010 which was broader though somewhat cooler at maximum. But the difference is so tiny as to be insignificant anyway. There is no significant difference between 1933, 1998, and 2010.
Rhys Jaggar says:
May 7, 2012 at 8:28 am
Has anyone done a Fourier analysis of that reconstruction to identify cyclical ‘beats’?
Looks like things around 500 years and in the few thousands……but that’s just eyeballing it.
Both the TSI and the Antarctic’s magnetic field variability (see graph 3 in the link http://www.vukcevic.talktalk.net/SSN-dBzA1.htm as in my post above) have one of the peaks around 490 years.
pochas,
Sorry if I’m confusing you. It is a complex ever changing interplay between the top down solar effects on the stratosphere and the bottom up oceanic effects on the troposphere.
That interplay alters the height of the tropopause and, more importantly, the average slope of the tropopause height between equator and pole so that the air circulation systems can slide latitudinally to and fro beneath the tropopause.
High solar activity results in LESS meridionality as during the late 20th century hence the need for a cooling stratosphere when the sun is active.
The observation of LESS ozone above 45km when the sun is active and MORE ozone above 45km when the sun is inactive is the only way to achieve the observed outcome in my opinion.
Leif often challenges me to point up something that can falsify my narrative. More ozone above 45km when the sun is active would be a real problem for me. Also less ozone above 45km when the sun is quiet.
So far, the observations are just as I need them to be.
Warm oceans push the jets poleward, cooler oceans allow them to withdraw equatorward.
Active sun pulls the jets poleward and a quiet sun pushes them equatorward.
The position of the permanent climate zones at any given moment reflects the net outcome of that interplay.
According to USHCNv2
1921: 54.37
1931: 54.37
1934: 54.61
2006: 54.95
1998: 55.09
That was what was in the database in 2006. Since that time temperatures before 1950 or so have been changed to cooler (they get modified cooler with each passing month, no idea why NOAA keeps adjusting older temperatures cooler each month or new temperatures warmer).
In 85 years there was really no significant difference. Meanwhile 2004 was colder than 1933:
1933: 53.78
2004: 53.64
So the reality is that there has been no overall “global warming” since the 1920’s – 1930’s. It cooled after the 1930’s and then warmed right back up again to about where it was then and it looks like temperatures are in another cooling period after peaking at around the early 2000’s.
Jan Perlwitz shows that he is ignorant of the Scientific Method. Perlwitz says:
“…there is nothing in there that is in contradiction to that greenhouse gases have been the dominant driver for the observed global warming over the last 35 years…”
But Perlwitz cannot provide a testable, verifiable, empirical measurement quantifying the specific percentage of global warming due to anthropogenic CO2, because there exists no such verifiable measurement. If such measurements did exist, the climate sensitivity number for 2xCO2 would be accurately known. It is not known. Esteemed climatologists have postulated sensitivity numbers from ≈1ºC, ± 0.5ºC, down to under 0.5ºC, to zero. Their highly educated views are more reputable than the IPCC’s preposterous, model-based 3+ºC.
Next, it is astonishing that GISS even employs someone like Perlwitz, who clearly was not even aware of the basic scientific concept of the Null Hypothesis. Yesterday, Perlwitz wrote:
“And why should anyone care about some stupid “null hypothesis” you have invented in your parallel universe? I do not see why I would have the burden of “falsifying” some hypothesis you have made up for yourself.”
First, the Scientific Method requires that scientists — including putative scientists such as Perlwitz, who puts forth a conjecture such as CO2=CAGW — have the duty to try and falsify Conjectures, Hypotheses, and even established Theories and Laws. But Perlwitz dodges that professionable responsibility, asking why he should have that burden. Obviously, Perlwitz does not understand the Scientific Method. No doubt he believes instead in Kuhn’s silly Post-Normal Science [another term for Jerome Ravetz’ ’emotion-based pseudo-science’].
The rigorous Scientific Method is based on testability and falsifiability, as quantified by Dr. Karl Popper. It is the gold standard of science. Anything less is embraced by those who don’t have either the rigor or the empirical facts to support their claims. [That is not to say that AGW does not exist. It may well exist. But it is only a conjecture. To be a hypothesis, AGW must be testable, and it is not. Thus, it is a conjecture; the first step in the Scientific Method.]
Mr. Perlwitz has made it crystal clear that he has never even heard of the Null Hypothesis: [“why should anyone care about some stupid ‘null hypothesis’ you have invented in your parallel universe?”].
Earth to Perlwitz: The Null Hypothesis is one of the basic principles of the Scientific Method. It is directly related to testability. And it has never been falsified. Dr. Kevin Trenberth has wrestled with the climate Null Hypothesis for the past couple of years. Anyone claiming to be adequate would already understand the Null Hypothesis. Obviously, readers here at the internet’s Best Science site know much more about the subject than this fake expert, who posts here during his taxpayer-paid workday.
I disagree with those who think Jan Perlwitz must be a sock-puppet screen name since his understanding of science is so deficient, beause he got too upset when someone outed his NASA position. Since Perlwitz is admittedly ignorant of the Null Hypothesis, and since he does not follow [or even understand] the Scientific Method, my suggestion to NASA would be to transfer Mr. Perlwitz to Muslim Outreach. Because it is clear that basic science goes right over Mr. Perlwitz’ head.
Of course everyone knows that in the grand maxima of debate-has-ended in group think manipulated science such solar effects are small and can be shuffled away with a small constant factor along with the AMO and anything else not worth mentioning. If it does not come from the political science high priests it does not count.
I looked up the Steinhilber paper that seems to be the source of the solar proxy that Leif sent along. The first line (explaining the importance of better solar activity proxies) says:
Kind of surprising to see such a strong statement made with no qualification.
Smokey says:
May 7, 2012 at 11:11 am
Jan Perlwitz shows that he is ignorant …
Well said. Nothing to add.
Leif makes a brief mention of another minima around 650AD. That probably coincides with this extract from my article carried here three years ago;
‘….Some of the Roman climate references are fascinating. This observation from a series of cold winters -after many warm ones- around the 8th century in Byzantium (centred around Modern day Turkey)
“Theophanes’ account recalls how, as a child, the author (or his source’s author) went out on the ice with thirty other children and played on it and that some of his pets and other animals died. It was possible to walk all over the Bosporus around Constantinople and even cross to Asia on the ice. One huge iceberg crushed the wharf at the Acropolis, close to the tip of Constantinople’s peninsula, and another extremely large one hit the city wall, shaking it and the houses on the other side, before breaking into three large pieces; it was higher than the city walls. The terrified Constantinopolitans wondered what it could possibly portend.”
It would be remiss not to connect the Roman warm optimum and the series of savage winters recorded above that afflicted Constantinople, with the great medieval warming of Greenland and the age of the Vikings several hundred years later. This enables us to contemplate the astonishing notion of Romans and Vikings from respective warm periods co-existing in the same era, as Vikings guarded the capital of the Eastern Roman empire.’
http://wattsupwiththat.com/2009/11/14/little-ice-age-thermometers-%E2%80%93-history-and-reliability/
tonyb
Resource guy says
http://wattsupwiththat.com/2012/05/07/solar-grand-minima-linked-to-cooling-period-in-europe/#comment-978755
true.
But in the end the (real) truth might hit them a bit?
http://www.letterdash.com/henryp/global-cooling-is-here
Svalgaard’s jamboree
7 May 2012 (Zurich)
Team of L. Svalgaard: Long-term Reconstruction of Solar and Solar Wind Parameters @ur momisugly ISSI, Hallerstrasse 6, 3012Bern, Switzerland (SeminarRoom, first floor)
Vukcevic:…. could claim the Wang Lean Sheeley data set is flawed since there was no an independent proxy which could test its accuracy
Leif Svalgaard:
That is what the workshop I”m at right now will be solving. It does not look to good for Wang Lean Sheeley.
Here is the agenda for this sub-topic at our ISSI workshop:
Reconstructions based on Cosmic Rays: Beer, McCracken, Steinhilber, Usoskin (devil’s advocates: Lockwood, Solanki, Cliver):
(1) 11-yr modulation during the Maunder Minimum: What does the modulation look like if no filtering is applied?
Was modulation strong or weak during this period in relation to the Spoerer minimum and later periods such as the Dalton minimum, the Gleissberg minimum around 1900 or the recent period of high activity?
Is there any evidence for a 22-yr cycle (e.g., Jokipii in the Sun in Time (1991) and Hiroko Miyahara at a recent IAU Symposium in Argentina)?
How did solar wind B vary at high time resolution? The auroral record (Siscoe, 1980) indicates a diminution of solar activity during the MM. Do you see evidence for this in the cosmogenic nuclide data?
(2) Dip in B centered on 1895: How consistent is the ice core (i.e., seen in both hemispheres? multiple cores?) evidence for this depression? Is the dip supported by geomagnetic data? By sunspot number data? Could Krakatoa
have contributed?
(3) Drop outs to B ~ 0 nT beginning with the Spoerer Minimum: Supported by 14C? Observed in multiple 10Be cores? Time scale of drop-outs? Contribution from volcanos?
(4) Comparison of Caballero-Lopez (2004), McCracken (2007), and Steinhilber et al. (2010). Evolution of time series. Consideration of the sensitivity of the B reconstructions to the local interstellar spectrum (LIS) used.
Thanks for finding this. I misread the o.p. – mistook the Steinhilber graph as part of the (blocked) Nature paper. Ach! Such a bloonder!
Tying these minima into historical events or periods is fascinating. There is a collection of historical references of various types to weather and climate here, mainly for Britain and Western Europe (the page linked is for the 6th-8th century A.D.):
http://booty.org.uk/booty.weather/climate/500_750.htm
And, in the downturns in the 4th millennium B.C,
“Tentative suggestion of a ‘downturn’: climatic conditions decade-to-decade now more variable, with occasional cooler / colder & wetter periods, BUT overall this spell still warmer than today! Storm tracks are thought to have been directed more towards the British Isles (perhaps biased to southern areas), and more vigorous. Periods of heavy rain, severe gales – these more frequent, and summer warmth was less reliable – with runs of such seasons classed as ” wet and cool”. European glaciers advance (again, but not in Britain) and forests retreat from higher elevations (storm damage?). Decline in warmth-loving tree species. ( a ‘disturbance of the global regime’: [Lamb] )”
– with a recovery after 3000 B.C.
http://booty.org.uk/booty.weather/climate/4000_100BC.htm
As a historian, it was the knowledge of fluctuating climate conditions throughout history that first made me utterly sceptical of the Team’s spurious assertions. I have not changed my mind. My own interests are in the major systems’ collapse around ca. 1200-1100 B.C., when there were destructions of important Middle Eastern and Anatolian civilisations, possibly and arguably linked to folk movements (and why were they moving if so? Climate?). This doesn’t seem to tie in with the minima shown on the graph but, as suggested in the link above, an eruption of Hekla might be implicated in some way.
BTW, shall we just presume Perlwitz (many puns occur to me) is the undergrad intern at NASA? S/he certainly shows all the signs. Even I, a non-scientist, knows what the Null Hypothesis is about. Where do they get them from?
“the amplitude of solar forcing is small when compared with the climatic effects and, without reliable data sets, it is unclear which feedback mechanisms could have amplified the forcing”
Clearly, there is a feedback mechanism.
In the IPCC report and the climate models, there is no feedback mechanism.
So, the IPCC and the climate models are wrong. For how many years have ‘we’ been saying that, and for how long have the climate mainstream been denying it?
What makes me really angry is that these people have happily piled enormous CO2 feedbacks into their models, without any evidence that the feedbacks exist – and yet they exclude the possibility of a solar feedback without discussion. (I would prefer to call it something like an indirect effect rather than a feedback.)
Rhys Jaggar says:
May 7, 2012 at 8:28 am
Has anyone done a Fourier analysis of that reconstruction to identify cyclical ‘beats’?
Looks like things around 500 years…..
_________________________
Yes Dr. Richard Feynman’s sister Dr. Joan Feynman. She used ancient records of the water levels of the Nile that were accurately measured plus auroral records. The Nile water levels and aurora records had two somewhat regularly occurring variations in common – one with a period of about 88 years and the second with a period of about 200 years.
Paper: http://www.agu.org/pubs/crossref/2006/2006JD007462.shtml
http://www.leif.org/EOS/JA089iA05p03023.pdf
tonyb says:
May 7, 2012 at 12:14 pm
Robert Graves references the classical historians (Herodotus and Pliny) in foonoting the “clashing rocks”, or wandering rocks of the Bosporous. The metaphor was used in his version of Jason, and I recall seeing elsewhere. Sounds like he was referencing the ice floes or icebergs coming down through the ice-swollen bosporous. The Symplegades were important enough to name. All pretty interesting imo.
Unattorney says:
May 7, 2012 at 9:08 am
How fast can it get how cold?
________________________________
Woods Hole at one point suggested within a decade (I am not sure the paper is still up unchanged.)
Gail Combs
and
Unattorney
There is a long article with lot of details on abrupt changes in the Earth’s climate here:
http://www.nap.edu/openbook.php?record_id=10136&page=10
Jan P. Perlwitz says:
May 7, 2012 at 9:48 am
Sorry to spoil the party that seems to be developing here, but this paper is about regional climate change in Europe due to changed atmospheric circulations patterns in the Northern Hemisphere caused by changes in the UV spectral range of solar radiation. These atmospheric circulation patterns, e.g., quantified with the Arctic Oscillation (AO) index determine how heat is re-distributed from low latitudes to high latitudes, whether the climate is more continental or more maritime over the land areas. The effect on the globally averaged energy balance is much smaller. For instance, there was a very cold winter in 2009/2010 in parts of the Northern Hemisphere, including Europe, which also could be seen in the strongly negative phase of the AO index. Nevertheless, the year 2010 was the warmest year on record in the GISS surface temperature analysis, and one of the warmest in the other surface temperature analyses…..
__________________________
With the shell game played with the global surface temperature, that statement is subject to a very large grain of salt.
……
The great dying of the thermometers: http://joannenova.com.au/2010/05/the-great-dying-of-thermometers/
Hansen’s slice and dice of US temperatures: graph
Australian temperature records shoddy, inaccurate, unreliable: http://joannenova.com.au/2012/03/australian-temperature-records-shoddy-inaccurate-unreliable-surprise/
An Adjustment Like Alice: http://notalotofpeopleknowthat.wordpress.com/2012/03/15/an-adjustment-like-alice/
Darwin adjustments: http://diggingintheclay.wordpress.com/2009/12/21/reproducing-willis-eschenbachs-wuwt-darwin-analysis/
New Zealand: A goat ate my homework: http://briefingroom.typepad.com/the_briefing_room/2010/02/breaking-news-niwa-reveals-nz-original-climate-data-missing.html
…..
With a record like that, I prefer the satellite lower Global Average Tropospheric Temperatures: http://www.drroyspencer.com/latest-global-temperatures/
So yes 2010 was warm but 1999 was warmer in the satellite records and so was 1933 (Dust bowl)