Nicola Scaffetta sent several people a copy of his latest paper today, which address the various solar TSI reconstructions such as from Lean and Rind 2008 and shows contrasts from that paper. While he suggests that TSI has a role in the temperature record, he also alludes to significant uncertainty in the TSI record since 1980. He writes in email:
…note the last paragraph of the paper. There is a significant difference between this new model and my previous one in Scafetta and West [2007]. In 2007 I was calibrating the model on the paleoclimate temperature records. In this new study I “predict” the paleoclimate records by using the solar records. So, I predict centuries of temperature data, while modern GCMs do not predicts even a few years of data!
Empirical analysis of the solar contribution to global mean air surface temperature change. Journal of Atmospheric and Solar-Terrestrial Physics (2009),
doi:10.1016/j.jastp.2009.07.007 By Nicola Scafetta
Abstract
The solar contribution to global mean air surface temperature change is analyzed by using an empirical bi-scale climate model characterized by both fast and slow characteristic time responses to solar forcing: and
or
. Since 1980 the solar contribution to climate change is uncertain because of the severe uncertainty of the total solar irradiance satellite composites. The sun may have caused from a slight cooling, if PMOD TSI composite is used, to a significant warming (up to 65% of the total observed warming) if ACRIM, or other TSI composites are used. The model is calibrated only on the empirical 11-year solar cycle signature on the instrumental global surface temperature since 1980. The model reconstructs the major temperature patterns covering 400 years of solar induced temperature changes, as shown in recent paleoclimate global temperature records.
Excerpts from the Conclusion (from a pre-print provided by the author)
Herein I have analyzed the solar contribution to global mean air surface temperature change. A comprehensive interpretation of multiple scientific findings indicates that the contribution of solar variability to climate change is significant and that the temperature trend since 1980 can be large and upward. However, to correctly quantify the solar contribution to the recent global warming it is necessary to determine the correct TSI behavior since 1980. Unfortunately, this cannot be done with certainty yet. The PMOD TSI composite, which has been used by the IPCC and most climate modelers, has been found to be based on arbitrary and questionable assumptions [Scafetta and Willson, 2009]. Thus, it cannot be excluded that TSI increased from 1980 to 2000 as claimed by the ACRIM scientific team. The IPCC [2007] claim that the solar contribution to climate change since 1950 is negligible may be based on wrong solar data in addition to the fact that the EBMs and GCMs there used are missing or poorly modeling several climate mechanisms that would significantly amplify the solar effect on climate. When taken into account the entire range of possible TSI satellite composite since 1980, the solar contribution to climate change ranges from a slight cooling to a significant warming, which can be as large as 65% of the total observed global warming.
…
This finding suggests that the climate system is hypersensitive to the climate function h(T) and even small errors in modeling h(T) (for example, in modeling how the albedo, the cloud cover, water vapor feedback, the emissivity, etc. respond to changes of the temperature on a decadal scale) would yield the climate models to fail, even by a large factor, to appropriately determine the solar effect on climate on decadal and secular scale. For similar reasons, the models also present a very large uncertainty in evaluating the climate sensitivity to changes in CO2 atmospheric concentration [Knutti and Hegerl, 2008]. This large sensitivity of the climate equations to physical uncertainty makes the adoption of traditional EBMs and GCMs quite problematic.
About the result depicted in Figure 6, the ESS curve has been evaluated by calibrating the proposed empirical bi-scale model only by using the information deduced: 1) by the instrumental temperature and the solar records since 1980 about the 11-year solar signature on climate; 2) by the findings by Scafetta [2008a] and Schwartz [2008] about the long and short characteristic time responses of the climate as deduced with autoregressive models. The paleoclimate temperature reconstructions were not used to calibrate the model, as done in Scafetta and West [2007]. Thus, the finding shown in Figure 6 referring to the preindustrial era has also a predictive meaning, and implies that climate had a significant preindustrial variability which is incompatible
with a hockey stick temperature graph.
The complete paper is available here:
Empirical analysis of the solar contribution to global mean air surface temperature change.
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Leif Svalgaard (22:47:45)
:”maksimovich (22:26:42) :
uv variance T. Dudok de Wit 2008
You have to multiply a) and b) to get the amount of variation in what matters [W/m2]. It doesn’t matter that the variation is 200% of a 1/1,000,000 of a W/m2.”
Irrelevant nonsense.UV variation and the instability, induced in the reactive diffusion atmospheric chemistry is frequency ” induced”,some chemical reactions are provoked only by light of frequency higher than a certain threshold; light of frequency lower than the threshold, no matter how intense, does not initiate the reaction.
This is well understood eg A. N. Gruzdev et al.2009: Effect of solar rotational variation on the atmosphere.
“Experiments with different forcing amplitudes have shown
that the responses of temperature and of the concentrations of
chemical species to 27-day forcing are non-linear. Their sensitivities
(not amplitudes) generally decrease when the forcing
increases. This conclusion is important to understand
the possible differences of observational studies obtained at
times of different forcing amplitudes.”
However on the other hand exact observations (instrumental) in the important “precurser” frequencies are at best minimalist.
How, Stephen? Why two out of three of the solar cycle cosmic ray peaks cool the earth in one phase of the PDO and two out of three of the solar cycle cosmic ray peaks in the next phase of the PDO warm the earth. I’ll leave the more quantitative explications of the ‘how’ to you and Leif.
============================================
Heh, I’m too busy figgerin’ out the ‘why’.
=========================
Leif Svalgaard (17:46:20) :
PaulHClark (17:02:48) :
nearly a doubling (of the solar open magnetic flux) over the last century
(Lockwood et al. 1999; Solanki et al. 2002).”
Not even Lockwood believes that any more. The ‘doubling’ was first suggested by me back in 1978 and elaborated on by Lockwood et al. in 1999 and modeled by Solanki in 2002. I and Lockwood have since realized that we were both wrong: http://www.leif.org/research/GC31B-0351-F2007.pdf
and that there has been no such doubling. The flux is now what it was 108 years ago.
An interesting non-sequiteur. That the flux is now what it was 108 years ago tells us very little about what it has been doing in between times eh Leif?
I would suggest that people who want to know more about how variable the sun really is have a look at the 2007 paper by Rouillard and Lockwood, after the corrections to the aa index detwermined by Leif were applied. It seems to have changed things from a ‘doubling’ to around a 40% increase (by eyeball).
http://www.eiscat.rl.ac.uk/Members/mike/publications/pdfs/2007/2006JA012130.pdf/
Right, back to work.
Leif Svalgaard (22:47:45)
uv variance T. Dudok de Wit 2008
You have to multiply a) and b) to get the amount of variation in what matters [W/m2]. It doesn’t matter that the variation is 200% of a 1/1,000,000 of a W/m2.”
maksimovich (22:26:42) :
Irrelevant nonsense.
Reply:
Yes, a total red-herring from Leif. It’s how earth systems respond to different wavelengths that is important when examining the impact of cyclical changes in UV, and perhaps other high energy radiation such a x-rays.
kim (23:57:49)
I’d love to know the answer.
Leif is far better qualified than me on the solar quantities side of things but I think I have a better grip on the mechanics of what happens after the solar energy reaches the Earth.
Note that my climate description does not depend on any particular level of solar variability as long as it is not zero. That is why Leif’s apparent enthusiasm to get it as near to zero as possible is rather unsettling to me. His efforts are an unnecessary distraction away from the mechanics of the overall global system that I am describing.
All I need is a radiative imbalance between solar energy penetrating the oceans and the oceans then releasing that energy to the air.
As long as there is such an imbalance on any scale then over time the system will behave in the way I have described it. I don’t thoink it is seriously disputed that such an imbalance is always present to some extent hence all the talk about ocean energy/heat content which does indeed vary.
I should leave Leif to his own devices because unless he can get solar variability down to zero then I should have no concerns.
As long as there is any solar variability however small (and he does admit some) then my ideas work and the problem of scaling from small solar variability to apparently large climate responses just requires extensions and enhancements of my climate description. I am happy to leave the oceanic side of the system to others. I am satisfied that I have got the ocean to air to space portion correct and in accordance with both basic physics and observations.
I am also sure that many other ideas such as those of Svensmark and others including possibly yourself, tallbloke Erl Happ and lots more can be slotted in but probably as second order modulating factors rather than primary drivers.
As far as the air is concerned the oceans are in absolute control and any realistic climate description has to be built on that.
Any challenge to my description can only be successful if it can be shown that the oceans are not in control once the solar energy arrives in the Earth’s climate syatem.
“The Sun has not varied the same way. See, e.g. http://www.leif.org/EOS/Holocene-TSI.pdf [Figure 3]. The typical deviations have been of the magnitude of 0.1% of TSI, commensurate with the change we had kicked around in our discussion.”
Well I’ve had a look at that Figure 3 and there, clear to all, are oscillations corresponding approximately with the Roman Warm Period, The Dark Ages, The Mediaeval Warm Period, The Little Ice Age and The Modern Maximum.
Stephen Wilde (23:08:27) :
Removal of solar variability from the climate equation leaves us with nothing to rely on to explain climate variability other than little green men.
Something is wrong with the solar observations, solar equations or our understanding of how solar changes affect the Earth. Possibly all three.
Why ignore all the other factors – GHGs (reduce radiation away), Albedo (reflect radiation away), Dust (check out the dust levels during ice ages – it is usually elevated), O3 (absorbs uv), milankovich cycles, etc
Every year the earth temperature cycles – in UK perhaps an average of -2 to +18C mainly due to the angle presented to the sun. The top few metres of sea also change in temperature (people swim in the UK sea during summer but less do in winter). Changes in solar radiation have a time lag to temperature of less than 1 year. Changes in temperature due to solar irradiation differences (11 year cycle) will be seen in the temperature record. A simple FFT of single station or global temperature shows that these cycles are only present in the background noise – using narrow band bandpass filters as I showed above, shows that the temperature fluctuation due to TSI is less than 0.15C peak-peak.
There is no significant 11 22 18.6 year cycles present in the temperature record.
The only sources of energy is the sun (ignoring the very small core heating). The only loss of energy is via radiation (however, growing things will store energy indefinitely). The sea will only “store” energy for short periods
The short term fluctuations in the sun output have little measured effect. That only leaves changing the radiation out or locking/releasing the energy in organic stuff for long term (greater than 1000years) variation
Correction, the paper says 70% increase in the solar open magnetic flux over the last century, not 40%. SO, no longer the doubling that “even Lockwood doesn’t believe anymore”, but still a very significant change, whichever way you look at it.
http://www.eiscat.rl.ac.uk/Members/mike/publications/pdfs/2007/2006JA012130.pdf/
bill (01:57:30)
Sorry bill.
I should have said ‘long term variability’ since ultimately it is the long term variability of the sun which is the only source of long term variability in oceanic energy content.
All the other variables act on shorter time scales and involve wavelengths that do not penetrate back into the ocean surface unless they affect the amount of sunlight reaching the surface so that it’s back to the sun again.
bill:
“There are no significant 11 22 18.6 year cycles present in the temperature record”.
Quite right, they are all swamped by the superimposed oceanic phase changes at about 30 year intervals.
That is the best evidence available for the oceans as drivers of events in the air and for events in the air being unable to drive the oceans.
Nothing else seems to be able to alter those phase shifts either so we need to be looking at internal oceanic variability on such time scales. The extent to which the solar cycles might be involved will be interesting to me and Leif in particular.
I’m calling them Wildean Ocean Cycles until there is a better term. For certain technical reasons I have been told that the term PDO is not suitable because the PDO is apparently just a statistical artifact derived from ENSO data.
Stephen 00:40:06
Thanks for that. We still have the thorny problem of how any magnifying mechanism for a solar phenomenon is prevented from a runaway effect on climate. This is the bucket of cold water Leif keeps pitching upon hot speculation. I think that climate regulation is complex enough to have so many varying feedbacks as to be self-centering, the water cycle being foremost among them, but I’m just speculating, at which Leif rightfully sneers. By the way, don’t underestimate Leif’s knowledge of the climate systems; he’s been thinking about them for a long while, and is well known for putting his finger precisely on the main flaw in a lot of theories.
I think I’ve never heard so loud
The quiet message in a cloud.
====================
Wilde (02:58:50) :
Quite right, they are all swamped by the superimposed oceanic phase changes at about 30 year intervals
But:
1. there are no ~30 year cycles either
2. ocean cycles simply move the heat around (unless I misunderstand?) They do not add to the overall energy content of the system. so this does not explain the temperature rise over the last 100years.
3. solar cycles are 11 and 22 years – sea temperatures to a few 10s of metres are heated and cooled summer to winter (a much shorter timescale). What property of water stores heat for 30 years at greater depths. For the “solar” radiation to reach these greater depths it will have heated the interveining water (to a higer temp) as it gets progressively absorbed.
Most of the info on inversion layers suggested that these are transient phenomena and very localised.
As I have said before, it’s all about radiation budget – more solar in or less radiation out is all that will give a significant long term heating. (perhaps one should also consider radiation trapped in the biomass or released by fossil fuel use?)
Moving trapped “heat” from one place to another in the ocean will not produce 100years of warming!
Leif Svalgaard (22:10:50) :
Geoff Sharp (21:58:06) :
Ok…thanks for the explanation, I must revisit my source suggesting the 16% variation (it did seem very credible at the time).
But I still think the argument of collecting TSI at sea level would end a lot of this debate.
————–
TSI has been measured like that for more than a century. http://en.wikipedia.org/wiki/Charles_Greeley_Abbot
Come on Leif that link is a joke….the project has never been undertaken. Also the amount of your UV variance in the TSI is also of question. I will come back shortly with some data. Stay tuned…..
“bill:
But:
1. there are no ~30 year cycles either”
What makes you think that ?
See here:
http://jisao.washington.edu/pdo/
As for a long term match between solar trends over centuries and the main climate trends from the Roman Warm Period to date see here:
http://www.leif.org/EOS/Holocene-TSI.pdf
where all the main changes in global temperature trend fit the estimated solar activity levels.
Now we all know that the figures don’t make sense but that doesn’t disprove reality. There is something wrong with the numbers and/or our understanding of the mechanisms.
The oceans do just move heat around but in doing so they also decrease and accelerate energy release to the air for 30 years at a time and that variation is superimposed on a background which seems to be solar induced somehow.
“By the way, don’t underestimate Leif’s knowledge of the climate systems; he’s been thinking about them for a long while, and is well known for putting his finger precisely on the main flaw in a lot of theories.”
Point taken, but from time to time it’s very tempting to respond with like for like.
Tenuc (00:36:50) :
Yes, a total red-herring from Leif. It’s how earth systems respond to different wavelengths that is important
I was not commenting on the effect, only on the number, 16%.
Geoff Sharp (06:13:19) :
TSI has been measured like that for more than a century. http://en.wikipedia.org/wiki/Charles_Greeley_Abbot
Come on Leif that link is a joke….the project has never been undertaken.
The historical development and present status of solar radiation measuring instruments
Yellott, J. I.
In: Sun II; Proceedings of the Silver Jubilee Congress, Atlanta, Ga., May 28-June 1, 1979. Volume 3. (A80-33401 13-44) Elmsford, N.Y., Pergamon Press, Inc., 1979, p. 2169-2173.
Abstract
The measurement of solar radiation intensity began in 1838 when Pouillet introduced an instrument for measuring the sun’s direct beam radiation and the name pyrheliometer. Electrical methods of radiation measurement were adopted in 1896 by Angstrom who introduced his comparison-type pyrheliometer. Abbot began his work in solar radiometry in 1905 with his silver disk and water-flow pyrheliometers which were used to establish the Smithsonian radiation scales in use until 1956. Between the two World Wars, electrical instruments were introduced for the continuous measurement of direct, diffuse and total irradiance, and integrators gave values of hourly and daily irradiation. With the space age, improved absolute radiometers and new radiometric standard to replace IPS 1056 were introduced.
tallbloke (02:12:52) :
Correction, the paper says 70% increase in the solar open magnetic flux over the last century, not 40%.
One little word ‘over’ is the important one. The solar magnetic field ‘over’ the 20th Century has varied in a cyclic manner with a maximum in the middle of the century. Lockwood computed his ‘centennial’ increase as the change from 1903 to 1956. It has now come down to where it started. So, no change ‘over’ the century. In addition, his values around 1900 are in error [as Rouillard has admitted] and in his latest paper [“The Rise and Fall of the Open Solar Flux (ApJ 2009)] he omits his erroneous data before 1905.
“kim (05:14:24) :
Stephen 00:40:06
Thanks for that. We still have the thorny problem of how any magnifying mechanism for a solar phenomenon is prevented from a runaway effect on climate. This is the bucket of cold water Leif keeps pitching upon hot speculation. I think that climate regulation is complex enough to have so many varying feedbacks as to be self-centering, the water cycle being foremost among them, but I’m just speculating, at which Leif rightfully sneers”
It’s a good point to suggest that any mechanism that can magnify the tiny solar variability enough to produce the observed climate response should be so powerful as to cause a runaway effect.
However I’m not sure that it does indeed need to be magnified in the sense of being made larger or rather amplified.
My point about sensitivity comes back here. A tiny solar change can apparently produce what appears to us to be a large climate response but so what ?
All one needs to start with is a radiative imbalance into and out of the oceans then add time then add the oceanic ability to sometimes accelerate and sometimes decelerate the rate of energy release to the air.
That seems to be enough to shift the size and positions of the air circulation systems but then that process itself changes the rate of energy transfer from surface to space and prevents a runaway situation.
You might call my comments speculation but I don’t think they are. They are logical interpretations of what we actually see.
The oceans do vary the rate of energy release to the air on 30 year timescales.I’ve no idea why.
The latitudinal positions of the air circulation systems do change in response (always following, never leading the oceans).The reason for that is clear in that faster energy release from the oceans increases the size of the equatorial air masses.
The speed of the hydrological cycle does change with the shifts in the air circulation systems. That is also clear.
The main global temperature trends do follow trends in solar activity back to at least the Roman Warm Period. Even Leif’s charts show that.
Now all that is data and a logical interpretation of that data is not
mere speculation.
One cannot ignore all that data just because what we know of the numbers involved fails to match that data.
The numbers are either wrong or irrelevant, possibly both.
Stephen Wilde (07:07:16) :
As for a long term match between solar trends over centuries and the main climate trends from the Roman Warm Period to date see here:
http://www.leif.org/EOS/Holocene-TSI.pdf
where all the main changes in global temperature trend fit the estimated solar activity levels.
If you compare the actual data rather than eyeballing/memory you get this: http://www.leif.org/research/2000%20Year%20Temp%20and%20TSI.png and that does not strike me as convincing or even suggestive.
Stephen Wilde (08:08:24) :
The main global temperature trends do follow trends in solar activity back to at least the Roman Warm Period. Even Leif’s charts show that.
Or even closer geomagnetic activity. There is, however remote, possibility they are part and parcel of the same controlling mechanism.
Here is my updated temp-geomag chart
http://www.vukcevic.talktalk.net/GeoMagField.gif
Stephen Wilde (08:08:24) :
The main global temperature trends do follow trends in solar activity back to at least the Roman Warm Period. Even Leif’s charts show that.
I don’t think so: http://www.leif.org/research/2000%20Year%20Temp%20and%20TSI.png
Temps on top, TSI on bottom. And in any case, the TSI variation is within +/- 1 W/m2 or +/- 0.07%, which over long time scales [as shown here] would correspond to +/- 0.05K, which is below what we can detect in the record.
Hypersensitivity as was pointed out would lead to runaways. “Tipping points” and all that. Since we have not had those [or maybe we have: snowball Earths etc if you believe in those] hypersensitivity is not likely.
vukcevic (08:41:16) :
Here is my updated temp-geomag chart
Based on a cherry picked [undisclosed] location. Pick another one [POT-SED-NGK] and you get the opposite variation: http://www.leif.org/research/Component.png
Leif Svalgaard (23:04:12) :
Nasif Nahle (22:58:53) :
Go on… Say “how”.
It was your how that was wrong.
Again, and for the last time, go on… Say “how”.
Leif Svalgaard (09:03:51) :
“Based on a cherry picked [undisclosed] location. Pick another one [POT-SED-NGK] and you get the opposite variation: http://www.leif.org/research/Component.png”
You could not be more wrong Sir, as a scientist of repute, you should know what to look for. Not my fault you looked at geomag data for 40 + years and failed to spot it.
If you looked at right PLACES you would have found this!
http://www.vukcevic.talktalk.net/GeoMagField.gif
You can check provenance of my data by getting in touch with your mates at NOAA (NGDC), with their powerful computers, they could check it in no time at all. If they whish to save time and effort, someone could contact me. In time, I will give a full description of the process, until then Sir, patience is advisable, or maybe look into some dubious aspects of the proposed SSN revision.
Do not waste time with TSI and SSN counts, get your self a magnetometer ! If you whish to counter AGW, ask NOAA to verify data with me, and then email chart to your member of parliament, to your senator or congressman, or whoever you voted to represent your interests!
http://www.vukcevic.talktalk.net/GeoMagField.gif
“If you compare the actual data rather than eyeballing/memory you get this: http://www.leif.org/research/2000%20Year%20Temp%20and%20TSI.png and that does not strike me as convincing or even suggestive”
The MWP, LIA and Modern Maximum look suggestive but not the pre 1000 AD period on those charts.
Personally I’d go for the solar activity level as being a more accurate reflection of pre 1000 temperatures due to the problems with global proxies for temperature that far back.
But it’s a judgement call and careful observations during the current lull in solar activity should resolve the issue in due course.