(Via the Hockey Schtick) A new peer reviewed paper published in The Holocene finds a significant link between solar activity and climate over the past 1000 years. According to the authors:
“Our results suggest that the climate responds to both the 11 yr solar cycle and to long-term changes in solar activity and in particular solar minima.”
The authors also find “a link between the 11 yr solar cycle and summer precipitation variability since around 1960” and that:
“Solar minima are in this period associated with minima in summer precipitation, whereas the amount of summer precipitation increases during periods with higher solar activity.”
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IRBSi is the proxy for precipitation/climate change and shows good agreement with solar activity. Figure 12. The comparison between the graphs of the IR-BSi and that of the solar cycles shows good agreement between the percentage of mineral materials of allochthonous and solar cycles reconstructed on the basis of changes in concentrations of 14 C in macrofossils. A good agreement is also evident between the concentrations of 18 O of foraminifera in the Norwegian Sea and the index IR-BSi. |
Solar forcing of climate during the last millennium recorded in lake sediments from northern Sweden
U Kokfelt University of Copenhagen, Denmark
R Muscheler Lund University, Sweden
Abstract
We report on a sediment record from a small lake within the subarctic wetland complex Stordalen in northernmost Sweden covering the last 1000 years. Variations in the content of minerogenic material are found to follow reconstructed variations in the activity of the Sun between the 13th and 18th centuries. Periods of low solar activity are associated with minima in minerogenic material and vice versa. A comparison between the sunspot cycle and a long instrumental series of summer precipitation further reveals a link between the 11 yr solar cycle and summer precipitation variability since around 1960. Solar minima are in this period associated with minima in summer precipitation, whereas the amount of summer precipitation increases during periods with higher solar activity. Our results suggest that the climate responds to both the 11 yr solar cycle and to long-term changes in solar activity and in particular solar minima, causing dry conditions with resulting decreased runoff.
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Recall that a paper published last year in Astronomy & Astrophysics shows solar activity at end of 20th century was near highest levels of past 11,500 years.
A paper published by a researcher at Max-Planck-Institute in Astronomy & Astrophysics reconstructs solar activity over the Holocene and finds solar activity at the end of the 20th century was near the highest levels of the entire 11,500 year record. The reconstruction spans the past 2,500 years, and the paper shows a ‘hockey stick’ of solar activity, following the end of the Little Ice Age in the 1800’s.
Fig. 11. TSI weighted reconstruction since approximately 9500 BC. In order to provide a better visualization, the evolution since 1000 BC is displayed in panel (b). The filled gray band represents region limited by the KN08-VADM and KC05-VDM reconstructions.
For reference, the red lines represent the 10-year averaged reconstruction by Krivova et al. (2010a).
Evolution of the solar irradiance during the Holocene
L. E. A. Vieira1,2, S. K. Solanki1,3, N. A. Krivova1 and I. Usoskin4
Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Str. 2, 37191 Katlenburg-Lindau, Germany
Laboratoire de Physique et Chimie de l’Environnement et de l’Espace (LPC2E/CNRS), 3A, Avenue de la Recherche, 45071 Orléans Cedex 2, France
School of Space Research, Kyung Hee University, Yongin, Gyeonggi, 446-701, Korea
Sodankyla Geophysical Observatory (Oulu Unit), POB 3000, Universiy of Oulu, Finland
Abstract
Context. Long-term records of solar radiative output are vital for understanding solar variability and past climate change. Measurements of solar irradiance are available for only the last three decades, which calls for reconstructions of this quantity over longer time scales using suitable models.
Aims.
We present a physically consistent reconstruction of the total solar irradiance for the Holocene.
Methods.
We extend the SATIRE (Spectral And Total Irradiance REconstruction) models to estimate the evolution of the total (and partly spectral) solar irradiance over the Holocene. The basic assumption is that the variations of the solar irradiance are due to the evolution of the dark and bright magnetic features on the solar surface. The evolution of the decadally averaged magnetic flux is computed from decadal values of cosmogenic isotope concentrations recorded in natural archives employing a series of physics-based models connecting the processes from the modulation of the cosmic ray flux in the heliosphere to their record in natural archives. We then compute the total solar irradiance (TSI) as a linear combination of the jth and jth + 1 decadal values of the open magnetic flux. In order to evaluate the uncertainties due to the evolution of the Earth’s magnetic dipole moment, we employ four reconstructions of the open flux which are based on conceptually different paleomagnetic models.
Results.
Reconstructions of the TSI over the Holocene, each valid for a different paleomagnetic time series, are presented. Our analysis suggests that major sources of uncertainty in the TSI in this model are the heritage of the uncertainty of the TSI since 1610 reconstructed from sunspot data and the uncertainty of the evolution of the Earth’s magnetic dipole moment. The analysis of the distribution functions of the reconstructed irradiance for the last 3000 years, which is the period that the reconstructions overlap, indicates that the estimates based on the virtual axial dipole moment are significantly lower at earlier times than the reconstructions based on the virtual dipole moment. We also present a combined reconstruction, which represents our best estimate of total solar irradiance for any given time during the Holocene.
Conclusions.
We present the first physics-based reconstruction of the total solar irradiance over the Holocene, which will be of interest for studies of climate change over the last 11 500 years. The reconstruction indicates that the decadally averaged total solar irradiance ranges over approximately 1.5 W/m2 from grand maxima to grand minima.
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What I find interesting is that the 1.5 W/m2 isn’t far from the value for CO2 forcing reported by CDIAC here:
http://cdiac.ornl.gov/pns/current_ghg.html
TomRude says:
January 3, 2013 at 5:49 pm
Sorry, you’ll have to read the work, carefully.
Oh, you mean that you don’t know where what I’m after is.
If you have something to contribute, say it.
Check from “Etudes de Cas” page 149 on… or from page 295 on… All these real cases show how NOAA models did not read the synoptic situation while the MPH concept made it logical and explained what happened.
TomRude says:
January 3, 2013 at 6:44 pm
Check from “Etudes de Cas” page 149 on… or from page 295 on… All these real cases show how NOAA models did not read the synoptic situation while the MPH concept made it logical and explained what happened.
That is not how one verifies a prediction. A verification must include all cases, not just carefully picked ones that fit.
The comparison includes just about a dozen cases in each batch. No quantification of the difference between NOAA and MPH, no discussion of statistical significance. No cigar.
TomRude says:
January 3, 2013 at 6:44 pm
Check from “Etudes de Cas” page 149 on… or from page 295 on… All these real cases …
here is how one verifies predictions:
http://www.swpc.noaa.gov/forecast_verification/Assets/Bibliography/i1520-0493-127-06-0956.pdf
LOL just as I expected, right on cue!
The real life differences between the two were trivial issues such as hurricane landfall, rainfall consequences and population protection…
Ciao Doc, never has a solar flare been closer to the dark side of the moon!
TomRude says:
January 3, 2013 at 7:34 pm
LOL just as I expected, right on cue!
The real life differences between the two…
As you can see there is a good reason the MPH remains on the fringe of meteorology.
Despite the inevitable aspersions (tiresome from any side of this issue), there does seem to be useful dialogue in this thread — and informative, at least to me. Leif is very demanding (if insufficiently willing to consider “possibilities”), which is good. Others (Rude, Schtick, etc.) undaunted (if insufficiently willing to admit when Leif has good points). Maybe it’s not in the nature of this kind of debate, but I wish the discussion would be less “defend/ attack” and more “where could there be weaknesses/ unknowns in each POV that, if explored, might give us a more efficient path to useful knowledge.”
Mosher’s point about skeptics being more “religious” recently than previously has some ring of truth for me since I’ve been following this debate since 2008 or 2009. But, as Leif easily admits, the AGW thesis is still on very shaky grounds.
Leif debunks the thesis that sun-spot variation (and all phenomena associated with it) is a significant factor in that modulation. He doesn’t believe there is data to make the case and, even where there are claimed correlations, he argues there’s insufficient explanation for a physical mechanism. Yet, he has not, to my memory (except for Milankovich cycles, possibly), pointed to where he thinks the modulation of solar input is coming from.
I’d be curious, Leif, to get your views of the current possibilities for those modulators — i.e., what data or theory are you aware of that should be directing research efforts to get a better understanding of climate modulators if not for sunspot (etc.) variation, CO2, and Milankovitch? Saying “ocean circulation” isn’t entirely satisfactory, unless there’s some idea for how to predict ocean circulation and its impact on temp changes such as Minoan, Roman, MWP, 20th century warmings and LIA coolings, etc. Or, maybe you’re convinced that the climate system is too chaotic to provide any explanatory mechanisms at any scales beyond weather and Milankovitch?
JP Miller says:
January 4, 2013 at 7:06 am
I’d be curious, Leif, to get your views of the current possibilities for those modulators — i.e., what data or theory are you aware of that should be directing research efforts to get a better understanding of climate modulators if not for sunspot (etc.) variation, CO2, and Milankovitch?
In my view Milankovitch is not in doubt, although there still are unexplained details [as with anything]. Solar activity also has an effect on the order of 0.1 degree, but we do not have good evidence that the Sun varies enough to explain any larger effect. CO2 clearly also has an effect, but probably small. ‘Ocean circulation’ has been used as a catch phrase for all the poorly understood interactions between ocean and atmosphere. Actual measurements of temperatures and flows at various depths are underway and may shed some light, but this is a long-term proposition [as also the ‘ocean cycles’ themselves are – the short-term ENSO conditions are not climate]. So, a partial answer to your question is “more data”. On the other hand chaos may be too prevalent to allow for predictability, just as it is for weather beyond a couple of weeks. On a personal note, I have been involved in sun-weather research for a long time and know the lure of such and the beauty of cycles and the satisfaction of finding an ‘effect’. I also know, of personal experience, of the frustration that ensue when the beautiful correlation fails. I take a dim view of armchair ‘researchers’ with the proverbial ‘open mind’ [has the brain fallen out?] who discover breakthrough science on a weekly basis.
Another paper on the subject….
http://www.sciencemag.org/content/301/5641/1890.abstract
Cyclic Variation and Solar Forcing of Holocene Climate in the Alaskan Subarctic
High-resolution analyses of lake sediment from southwestern Alaska reveal cyclic variations in climate and ecosystems during the Holocene. These variations occurred with periodicities similar to those of solar activity and appear to be coherent with time series of the cosmogenic nuclides 14C and 10Be as well as North Atlantic drift ice. Our results imply that small variations in solar irradiance induced pronounced cyclic changes in northern high-latitude environments. They also provide evidence that centennial-scale shifts in the Holocene climate were similar between the subpolar regions of the North Atlantic and North Pacific, possibly because of Sun-ocean-climate linkages.
@ur momisugly Leif Svalgaard
If an “armchair
researcheranalyst” could take another minute of your time, I think we’ve been talking past each other.Seemingly, there’s an overriding assumption that there is a linear relationship between heat flux (W/m^2) and global average temperature regardless of frequency. If we were discussing any other process that involves the conversion of radiant energy into some other form of energy, frequency would indeed be of utmost concern; i.e. a significant if not critical variable.
Three examples:
Temperature gradient above the tropopause where temperature increases with increasing altitude; radiant energy is converted to thermal energy, but the frequency of the radiant energy is a critical variable not just the total heat flux.
Photosynthesis; radiant energy is converted to chemical energy, but the frequency of the radiant energy is a critical variable not just the total heat flux.
Vitamin D production in human skin, where radiant energy is converted into molecular energy, but the frequency of the radiant energy is critical, not just the total heat flux.
So, my question is why wouldn’t frequency matter in the conversion of radiant energy into thermal energy as “revealed” in the global average temperature metric? (In other words: Why would 1 W/m^2 IR have the exact same effect on global average temperature as 1 W/m^2 UV?)
Or perhaps my perception of the “assumption” is wrong; please explain if this is the case.
John West says:
January 4, 2013 at 12:34 pm
Why would 1 W/m^2 IR have the exact same effect on global average temperature as 1 W/m^2 UV?)
Because once that 1 W/m2 is absorbed the absorber radiates the same. In addition, there is not much energy in the UV [compared to IR] and most of it is absorbed by the atmosphere higher up and therefore does not heat the ground. The effect of UV is usually not framed in terms of W/m2 but in the chemical changes in the upper atmosphere.
lsvalgaard says:
“Because once that 1 W/m2 is absorbed the absorber radiates the same.”
That would be assuming 1) it’s absorbed in the first place since real materials have different albedoes to different wavelengths for example snow would reflect most of a 1 W/m2 exposure while absorbing most of a 1 W/m2 IR exposure, 2) the absorber is in thermodynamic isolation since an absorber radiates in relation to it’s temperature (S-B Law) and the Law of Conservation of Energy requires a temperature gradiant to initiate a flow through convection/conduction such that only a thermodynamically isolated body could increase in temperature to match emission to an absorbed heat flux, and 3) absorbtion “mode” is in solid or liquid molecular motion i.e. not a conversion from radiant energy to some other energy that isn’t reflected in temperature, such as visible light being absorbed and converted to chemical energy in photosynthesis.
Let’s just talk about something no one (except a few of us nerds) cares about for a second; the stratosphere.
The stratosphere absorbs aprox. 100 W/m2 UV and is warmed from around -60°C to around 0°C while IR has little effect at all on stratospheric temperature (hardly any GHG’s), therefore one could say that stratospheric temperature “sensitivity” to UV is much higher than stratospheric temperature “sensitivity” to IR.
Back to Earth:
So, around 30 W/m2 UV reaches the surface and solar UV varies by about 10%; giving us an easy 3 W/m2 variance which is awfully close to the 3.7 W/m2 increase from 2XCO2.
But I’m not just talking about UV, I’m talking about the entire solar spectrum variation. A variation of components that is not well reflected in TSI variation.
Let me put it an entirely different way. In the broader sense of climate sensitivity (CS) I have a very difficult time accepting it as a value as apposed to a function. That function IMO should include frequency and some sort of “absorbtion” clarifier. Take the extreme case of snowball Earth for example; obviously, UV reflects more while IR is still absorbed. So, if we defined climate sensitivity as the change in global average temperature to a change in heat flux @ur momisugly frequency @ur momisugly condition.
(Just making up some conditions: S=snowball, G=glacial, I = interglacial, H=Hothouse)
(just making up values here)
Perhaps: CS@ur momisuglyIR@ur momisuglyG=2°C/W/m2 while CS@ur momisuglyUVa@ur momisuglyG=0.1°C/W/m2.
But maybe: CS@ur momisuglyIR@ur momisuglyH=0.5°C/W/m2 while CS@ur momisuglyUVa@ur momisuglyH=1°C/W/m2.
I don’t know, it just seems that sort of approach would make more sense.
arrrrrggg:
reflect most of a 1 W/m2 exposure = reflect most of a 1 W/m2 UV exposure
and
I don’t know, it just seems that sort of approach would make more sense than trying to assign (discover) a climate sensitivity value to all frequencies at all conditions.
John West says:
January 4, 2013 at 3:46 pm
Back to Earth:
So, around 30 W/m2 UV reaches the surface and solar UV varies by about 10%
One can go around in circles with wrong numbers. The near UV that makes up 95% of the UV that reaches the surface does not vary 10%, but 1% or less.
I think what matters in the end is simply how much energy is available.
Leif, thanks. Yes, I agree that the best scientists have an ability (intuition?) to sort out the many things that “appear to” correlate and focus their research efforts on those relationships that might well have physicality. And, yes, pointing to lots of things that appear to covary and say “look at this” isn’t helpful unless there’s then a theory (even if half-baked) that’s potentially physical and further research to attempt to show it’s wrong. But, to their credit, some of the armchair analysts on this blog (e.g., Stephen Wilde) are working to do just that.
However, one thing I don’t understand is why you harp so much on TSI per se and seem resistant to considering that some other aspect of solar activity (effect of various wavelengths, electromagnetic effects, etc.) might influence phenomena such as clouds, water vapor, ozone, etc. that could modulate effective TSI impact. Do you rule out any such possibilities, or is it only the particular possibilities mentioned in this blog that you have rejected?
I’ll take your word on the solar stuff, but I tend to disagree with “what matters in the end is simply how much energy is available” there’s a qualitative difference among forms of energy, having the same units does not make them identical. Depending on the energy forms being compared the same quantities of energy may not be able to accomplished the same amount of work. I’ll go back to the armchair analyzing and come back when I can put some quantitative physics around it.
Have a good weekend! And thanks!
JP Miller says:
January 4, 2013 at 4:54 pm
However, one thing I don’t understand is why you harp so much on TSI per se and seem resistant to considering that some other aspect of solar activity
Several reasons: the TSI is where the energy is, all the other ones are orders of magnitude smaller; almost all the other indicators vary the same way as TSI, have the same cycles, etc, so TSI is often just used as a shorthand for ‘solar cycle variations’; there is a well-understood theory of temperature variation due to TSI, there are none for the others; there are many ‘myths’ that people just parrot without understanding what they are saying; there are unknown feedback and amplifiers in play, etc.
Willis Eschenbach says:
January 2, 2013 at 5:37 pm
DocMartyn says:
January 2, 2013 at 3:22 pm
rgbatduke, we did the bolus addition of 14C using the atmospheric H-Bomb tests. The pseudo-first order decay is approximately a decade.
What you are looking at there, Doc, is the “residence time” of a molecule. How long does the average CO2 molecule stay in the atmosphere? You are right, it’s short, about 5-8 years.
That’s not the measurement Robert Brown (rgbatduke) is discussing. He is looking at what is called the “e-folding time”, or perhaps the half-life…
The relation between half life and mean residence time is very simple.
half-life = 0.693 x mean residence time
0.693 is Ln2.