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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“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”
Say what?
I thought we were told that the models have proven that only CO2 affects the climate?
Solar-flares have been suspected of having the greatest influence on changes in the climate by a majority of respected scientist for a hundred years.
What!!! This is sacrilege!!!
Leif
After reading your work for quite a while now, am I detecting a subtle shift in your own position regarding solar influences? To me the ultraviolet angle is interesting as we spacecraft guys know quite well that variations in UV have a major influence on the exosphere, with the tenuous atmosphere expanding and contracting in direct proportion to the magnitude of the change.
Now I personally don’t know what that variation means but I do know that the change is quite large and that if this influence continues downward in the atmosphere, which we know it does to at least below 100,000 ft, then we may have a mechanism for the interaction. In all of the remote sensing work that we did there is a quaint and funny nomenclature for altitudes between about 120,000 ft and low orbit. It is called the ignorosphere as it is too high for balloons, planes, and too low for orbiting spacecraft or anything but sounding rockets that spend only a couple of minutes transiting that region.
Interesting….
There is much that we do not know.
But we can’t regulate the solar footprint, so there’s no money (taxes) to be made from this.
Made Der Spiegel today but only in German so far. They do mention how cooler periods are associated with starvation, wars, disease and general ugliness—what a revelation!
I’ve been looking at European temperatures wrt wine-making. When the greatest cooling is depends on where you look. Same thing with proxy data of stalactites. And comparisons with SW US stalactites.
Not hugely, but 20 or 30 years. It looks like why Mann et al could claim that the MWP was regional, not global. But I’m wondering if that regional-not-global is actually THE characteristic of all of our planetary climate, that it takes time to move around.
Consider this: right now the Arctic, according to Hansen’s data, is warming rapidly and greatly. Meanwhile, Antarctica is cooling and expanding ice-wise. Is this any different from the data of the MWP? If you used the same regional-not-global analysis for the MWP today, would you also conclude that their is no “global” warming?
Is this showing a bait-and-switch?
“the ignorosphere”
Doesn’t that also describe a group of climate scientists when confronted with data that does not support “the cause”?
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.
I see it’s published in Nature Geoscience.
Perish the thought that solar inputs could affect climate science research published in Nature magazine itself.
What’s the IF for Nature Geoscience vis a vis Nature?
And what do climate scientists think about the relative merit of papers printed in either journal??
It’s interesting they have to pay homage to the climate models. Hail to the modelers!
Why is the graph only going to 2000?
We don’t know what happened afterwards?
I am reporting a gradual decline in Maxima
(which nobody who is anybody – as climate websites go – seem to be plotting)
and it goes negative after 1994
http://www.letterdash.com/henryp/global-cooling-is-here
I think it must be linked to reduced TSI>?
How fast can it get how cold?
It is global, not regional. There is plenty of data supporting the global nature of cyclical climate variations.
To achieve circulation changes one must change the vertical temperature profile of the atmosphere.
The sign of the necessary change in stratospheric temperatures as a result of solar variability is the opposite of conventional climatology hence recent evidence that there is a reverse sign solar effect in the upper atmosphere as publicised by Joanna Haigh and others.
This is the most likely scenario:
http://climaterealists.com/index.php?id=6645
“How THe Sun Could Control Earth’s Temperature”
Just eyeballing, it appears that the 650 excursion is expressed.
Leif: why do you consider this one of the better reconstructions?
Dr. S got his ‘SSN ironing board’ set up at a solar jamboree somewhere or another. I wonder what might come out of it.
He postulates that, based on the Wolf’s magnetic needle records, the sunspot numbers are wrong, and whole thing needs flattening out.
Of course, he could be right but I have reason to think he is wrong.
Wang ,Lean and Sheeley have used simple algorithm to calculate TSI on the based on the accepted sunspot count. It was reasonable that he should claim that the WLS data set is flawed since there was no an independent proxy which could test its accuracy.
Things have changed, now we do have a good proxy in the Antarctic’s magnetic field bi-decadal variability, based on the geomagnetic data not only from the old Wolf’s single magnetic needle on the Swiss mountainside, but on thousands of records collected all around the globe since 1600.
http://www.vukcevic.talktalk.net/SSN-dBzA1.htm
These records show that the WLS data are good and consequently the currently accepted sunspot data are more realistic than the ‘revised’ set proposed by Dr. Svalgaard and his followers, if has any.
Henry@Stephen Fisher Wilde
I tend to agree with you that it (i.e. the cooling) is global
What did you think of my new tables which I have stratified now in the way as discussed…
Henry@Unattorney
It seems we could currently be cooling at an (alarming) rate of 0.1 degree per annum/.
the problem is: I don’t know where it will stop
http://www.letterdash.com/henryp/global-cooling-is-here
Weather is regional. Climate used to be regional. It still is, but that inconvenient fact has been forgotten with the urge to sell the GHG master control knob concept.
Homeric.
Stephen Wilde says
\….then more UV from a more active sun should make the stratosphere
even warmer. I suspect that premise to be mistaken.
There are….
Henry says
I knew that!
I figured that out some time ago
Amazing.
I am sure I even have said it here somewhere
More UV puts more ozone up in the upper atmosphere which deflects more sunlight…
it is a paradox…
Stephen W: the authors seem to be invoking your theory.
Dennis Ray Wingo says: “Leif, [a]fter reading your work for quite a while now, am I detecting a subtle shift in your own position regarding solar influences? To me the ultraviolet angle is interesting as we spacecraft guys know quite well that variations in UV have a major influence on the exosphere, with the tenuous atmosphere expanding and contracting in direct proportion to the magnitude of the change.”
Leif assured me some time ago that the ionosphere is so tenuous that it can have absolutely no effect on weather. I’m not so sure. For one thing, the ionosphere is deep enough that a photon can’t pass through it without colliding with at least one molecule. I also wonder changes in the ionosphere can affect the effective black body temperature of the night sky.
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.
Although many here may wish to draw a different conclusion from this paper, 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, and there is nothing in there that contradicts a continuing global warming due to a continued increase in greenhouse gases in the future, even if the sun went to a similar state as during the “Homeric minimum”.
“More UV puts more ozone up in the upper atmosphere which deflects more sunlight…
it is a paradox…”
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.
Low solar activity increases ozone above 45km to cause a warming mesosphere and stratosphere DESPITE less ozone below 45km.
It has to work that way otherwise we could not see zonal jets at a time of more active sun and meridional jets at a time of less active sun. The reason being that a warming stratosphere is associated with meridional jets and a cooling stratosphere with zonal jets.
It is well know that so called sudden stratospheric warming events send surges of cold polar air equatorward which is just the same mechanism on a smaller short term scale.
I think that reverse sign solar effect on ozone from around 45km is the reason why the lapse rate reverses at the stratopause between stratosphere and mesosphere. The stratopause is at around 45km to 50km and varies in height in line with changes in solar activity.
The cessation of stratospheric cooling in the 90s and the start of slight stratospheric warming was coincident with declining solar activity and fits in with the tropospheric cooling trend from the mid 90s revealed in your ‘Pool Table’ data.
The troposphere cools when the stratosphere warms and vice versa.
The established view that the active / quiet sun warms / cools the whole atmospheric column must be wrong.
Jan says
Although many here may wish to draw a different conclusion from this paper, 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, and there is nothing in there that contradicts a continuing global warming due to a continued increase in greenhouse gases in the future, even if the sun went to a similar state as during the “Homeric minimum”.
Henry@Jan
jy bent ook een grappemaker…
It has been cooling on earth,
since 1994
http://www.letterdash.com/henryp/global-cooling-is-here