Guest post by Alec Rawls
Solar physicist Sami Solanki and his colleagues at Germany’s Max Planck Institute for Solar System Research helped pioneer the use of cosmogenic isotopes from ice cores to create a proxy record for solar activity going back hundreds and thousands of years. Together with a group led by Ilya Usoskin at University of Oulu in Finland, Solanki describes “grand maximum” levels of solar activity from 1920 to 2000, with the sun being especially active since the 1940’s.
Comparing this solar record to temperature, these scientists find a strong correlation between solar activity and temperature persisting until quite recently. For example, over the period of the instrumental temperature record, a 2004 paper by Solanki and Krivova finds that the correlation is quite close, “however”:
However, it is also clear that since about 1980, while the total solar radiation, its ultraviolet component, and the cosmic ray intensity all exhibit the 11-year solar periodicity, there has otherwise been no significant increase in their values. In contrast, the Earth has warmed up considerably within this time period. This means that the Sun is not the cause of the present global warming.
But does this conclusion follow? Their own evidence says that until 1980 the dominant driver of climate was solar activity (and their longer-term temperature-proxy comparisons say the same thing). So how can they assert that two decades of the highest solar activity on record can’t be the cause of concurrent warming?
I suggested to Solanki and his colleagues that they must be implicitly assuming that by 1980 ocean temperatures had already equilibrated to whatever forcing effect the high level of solar activity was having. Otherwise warming would continue until equilibrium had been reached. Yet equilibration is never mentioned in any of their analyses.
Many thanks to Sami Solani and Manfred Schuessler for their important reply, finally making the implicit explicit. Here is the main part of their answer:
Dear Mr. Rawls,
You have raised an interesting question. Correlations between solar activity indices and climate assume that there is a constant lag between solar and climate variability (this is implicit in the nature of correlations). In some cases authors even implicitely or explicitely assume that this lag is zero, i.e. that the relationship is instantaneous. If we consider the period of time up to ca. 1970, then this lag lies roughly between 0 and 12 years (e.g., Solanki and Krivova 2003). Newer reconstructions, such as that of Krivova et al. (2007) tend to favour the lower lag. If we consider the period since 1970 alone, then the solar irradiance hasn’t shown an increasing trend, but rather a decreasing one, in contrast to global temperature, which has increased substantially. If this increase is due to the hypothetical influence of the oceans, as you suggest, then of course these short lag times would not be realistic. This, however, would mean that the relatively good correlation between solar and climate variability prior to 1970 would also have to be discarded as due to chance and would cease to be of relevance. Lags cannot be changed at will, certainly not without a good physical reason, i.e. one based on computations, that at least approximately model the Earth system’s behaviour.
To clarify, I did not quite suggest that post-1970 warming might be due to the influence of the oceans. I suggested that it could be due to the sun. The hypothesis isn’t that the oceans were giving up stored heat content but that they were continuing to absorb solar-driven heat. (Under the GCR-cloud theory, high solar wind blows the clouds away, increasing the amount of solar shortwave that pours into the oceans.)
Since Solanki and Schuessler see this slow-ocean-equilibration story as incompatible with short correlation lags, they are clearly identifying short lags with rapid equilibration. The question is whether this identification makes sense. If the equilibration process is not rapid, does it really mean that the short correlation lag between solar activity and temperature that these folks discovered must be mere chance? A simple counter-example shows the answer to be no.
Day vs. season
If you map the diurnal correlation between the strength of the sun’s rays on your back porch and temperature in the shade, you will find that the maximum correlation occurs with only a few hours lag. At noon, sun strength is no longer increasing, while the rate of temperature increase is near its maximum, with temperatures continuing to rise until sometime mid-afternoon.
So you find this very strong and rapid correlation between sunlight and backyard temperature. You’ve been plotting it for a few months, and now it’s June. There is no significant change day by day in the strength of the sun’s rays, or their duration, yet somehow peak backyard temperatures keep going up. The end of June is hotter than the beginning of June. Do you say that this can’t be explained by the sun because solar forcing has not been rising and you know that the temperature response to the sun is only a few hours?
This is exactly what Solanki et al. are doing. Instead of day vs. season they are finding temperature signals within the solar cycle and from one solar cycle to the next and assuming that these same response times apply to longer term changes in solar activity. But climate systems don’t just respond on one time scale.
This is what came out of the previous post, where Mike Lockwood cited the rapid response time that was estimated by Stephen Schwartz on the assumption that the planet can be represented by the simplest possible energy balance model with only one heat sink. Make the model one step more realistic by giving it two heat sinks, so that the sun and the atmosphere do not warm the entire ocean at once, but warm an upper layer which in turn, over time, transfers heat to a deeper ocean layer, and everything changes. Time to equilibrium from a step-up in forcing could be centuries, but as Daniel Kirk-Davidoff’s analysis of the two heat-sink model shows, a correlation study that does not span several times the period of any long term fluctuation in forcing will only pick up the relatively rapid response time of the upper ocean layer, revealing next to nothing about time-to-equilibrium for the full climate system.
The one thing we can say from the observed rapid temperature response to short term fluctuations in solar activity is that solar activity clearly does drive temperature. Add that the sun does not warm the ocean all at once—that the deeper ocean is warmed over time by the upper ocean as the two heat-sink model describes—and we can expect that the demonstrated warming effect of solar activity will cause long-period deeper ocean warming when there is a longer period rise in solar activity.
That is, the short time-lag correlation actually implies that longer period responses should also be taking place, once the most obvious steps to model realism are incorporated. Thus no, the finding of a short correlation lag does not contradict a solar explanation for late 20th century warming but supports it, just as the suns’ warming of the day supports a solar explanation for seasonal change.
This is why it is so important that widespread but unstated assumptions of rapid equilibration be made explicit. The assumption does not stand up to scrutiny, yet it has been allowed to escape scrutiny even as it does the heavy lifting in many scientists’ dismissal of a solar explanation for late 20th century warming. So again, many thanks to Doctors Solanki and Schuessler for making this assumption explicit.
GCM equilibration time
Here is the rest of the Solanki-Schuessler response:
You can rightly argue that a simple linear analysis, such as that carried out by Solanki and Krivova 2003, does not fully reflect the complex behaviour of the Earth system. Indeed, such an analysis does not replace introducing the solar irradiance record into a GCM (General Circulation Model), which includes the coupling between the oceans and the atmosphere, and computing the influence of the Sun’s behaviour. Such studies have not, to our knowledge, reached conclusions that differ significantly from those reached by the simple correlation analysis. If anything, they tend to indicate that the influence of the Sun is even smaller than the correlation studies suggest. The attached review paper gives a good and up-to-date overview of the state of research on Sun-climate relations. Figs. 27 and 28 (pp. 36 and 37) of this paper show that GCM models support the assumption of a short time lag, i.e., quasi-instantaneous reaction of the global temperatures on changes in forcing (as is well known to be the case for major volcanic eruptions, for instance). We think that this is due to the fact that only the mixed layer of the oceans is involved in climate variations due to short-term (decadal to centennial) variations of the forcing, so that the global equilibrium time of the oceans is irrelevant – but you may want to contact a climatologist if you wish to obtain more detailed information.
We hope to have been of help.
Sincerely yours,
Sami Solanki and Manfred Schuessler
What I have been able to glean about equilibration time in the IPCC GCMs is rather different from what Solanki and Schuessler assert. This came up in Part 2, where Schwartz’ short estimated time constant implied a low climate sensitivity, prompting a vigorous response from Gavin Schmidt and other “consensus” GCM compilers. Foster, Schmidt et al. said that in contrast to Schwartz’ 4-6 year time constant, the AR4 model “takes a number of decades to equilibrate after a change in external forcing.”
In a later RealClimate post, Schmidt suggests that:
Oceans have such a large heat capacity that it takes decades to hundreds of years for them to equilibrate to a new forcing.
The review paper that Solanki and Schuessler cite is Solar Influences on Climate, by Gray et al. 2010. S&S cite Gray’s Figures 27 and 28 as support for quasi-instantaneous temperature adjustment in response to a change in forcing, but it is hard to see the connection. The figures are from AR4 and just show the amount of recent warming that is attributed to CO2 in the AR4 models. That would be all of it, post 1955:
Figure 27 [Gray]. Global mean temperature anomalies, as observed (black line) and as modelled by thirteen climate models when the simulations include (a) both anthropogenic and natural forcings and (b) natural forcings only. The multi-model ensemble mean is shown in grey, and individual simulations are shown in colour, with curves of the same colour indicating different ensemble members for the same model.
Are S&S interpreting Figure 27a as showing a fit between forcings and temperature (in which case the close fit to observed temperatures would indeed indicate a rapid response to forcing)? But this isn’t what the graph shows at all. It compares observed temperatures to the temperatures that the AR4 model predicts in response to 20th century forcings. Equilibration speed (or lapse time) is one of the variables that modelers tweak to achieve a fit between predicted and actual temperatures.
It is not surprising that modelers manage to achieve a reasonably close fit over their calibration period (the 20th century). Every detail of their very complex model is tailored to achieve this. They presumably could achieve this level of fit in many ways. The fact that they do achieve it doesn’t say anything about how they achieve it. The equilibration speed could be anything.
Of course we do know a few fun facts about how the AR4 models are fit to the data. In particular, we know that the IPCC engages in blatant question begging by including only one solar variable in its AR4 models: Total Solar Irradiance, which is parameterized by the IPCC as having 1/14 the warming effect of CO2 (0.12 vs 1.66 W/m2).
Gray’s Figure 27 makes the impact of this assumption graphic. When total solar effects are fixed on the input side of the model to have 1/14th the warming power of CO2, the model output “shows” CO2 to be the dominant climate driver. It’s called “garbage in, garbage out.”
Data vs. assumption
The question is why Solanki and Schuessler are satisfied with the IPCC’s TSI-only characterization of solar effects when their own data screams out so strongly against it. They look at how little solar effect on climate is built into the AR4 model and say:
If anything [these models] tend to indicate that the influence of the Sun is even smaller than the correlation studies suggest.
The discrepancy between their correlation studies and the AR4 model can be seen in the glaring difference between 1955-1980 in Figure 27 above and in Figure 2b from Solanki and Krivova:
The black line is instrumental temperature. Dotted lines are inverted GCR (reconstructed, and as measured in Climax Colorado since 1953). Close correlation between solar activity and temperature continues to 1980.
Henrik Svensmark finds a still longer correlation. After controlling for PDO, he finds that the short term correlation between solar activity and temperature continues to the present day:
FIG. 2 [Svensmark]: … The upper panel shows observations of temperatures (blue) and cosmic rays (red). The lower panel shows the match achieved by removing El Nino, the North Atlantic Oscillation, volcanic aerosols, and also a linear trend (0.14 ± 0.4 K/Decade).
There is no way that the high degree of short term correlation between solar activity and temperature observed by Solanki and Schuessler pre-1980 can be explained by the tiny variations in Total Solar Insolation (about a tenth of a percent over the solar cycle). Yet when they see how the IPCC’s TSI-only model under-predicts their own observations, they don’t question the IPCC’s fixing of total solar effects at 1/14th the strength of CO2, but count this garbage-in model as evidence against their own data. That’s not right guys. Data is supposed to trump theory/assumption. That’s the definition of the scientific method.
Solanki, Schuessler and their colleagues have done some of the most important climate research of the last decade, creating several of the paleo-reconstructions of solar activity that make extended solar-climate studies possible. Unfortunately, they are misinterpreting the correlation between solar activity and temperature. Short correlation lags do not imply rapid equilibration. They just reflect the rapid temperature response of the upper ocean layer, leaving the equilibration speed of deeper ocean layers an open question. Thus short correlation lags provide no grounds for dismissing a solar explanation for late 20th century warming. Scientists who have been presuming otherwise should be willing to reconsider.
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I think they are right–solar activity cannot account for the spike in the records from 1980 to 2000. I think the overwhelming evidence is that those record were spiked–fudged, falsified.
Solar activity better accounts for the rise than AGW, much better. The shape of the curve and considering the rise out of the LIA, simply does not correlate to fossil fuel use.
But the Danish scientist who found that all the coldest records were being deleted from the records, your graph of number of stations versus temperatures–now that is a plausible explanation that truly fits the data.
I think the pot of water on the stove creates an unwarranted acceptance of linearity in the climate response. In fact the environment responds with significant phase changes in the water component. Water vapor and clouds. To bring the pot of water into a better kind of representative example it would be necessary to consider the affect of steam being released and the impact it has on the effective heating of the water in the pot – but because the experiment is so unlike the global environment, that connection cannot be made.
Recommend finding a better candidate for a climate simile.
I will say that there is not an equilibrium in the oceans or the athmosphere. This word should not be used. I just confuses the issue.
jack morrow says:
April 7, 2011 at 6:41 am
Sir Thomas More: Why Richard, it profits a man nothing to give his soul for the whole world… but for Wales?
Further to my post at 9.14am.
The climate system is continously variable. I the cognescenti cant deal with it as such they should not insist.
The example of the pot put on the boil is an excellent example of the mistake in trying to correlate temperature with forcings.
Forcings control the rate of change in temperature, not the absolute temperature. If you turn the heat up on a pot of water, it will come to a boil faster. If you lower the heat, it will come to a boil slower. In both case the temperature goes up.
This is where Climate Science has got it wrong. They are looking at the temperature of the water in the pot, and saying that since the temperature of the water is going up, the forcings must be going up.
But as the pot of water shows, the temperature can increase even if the heat is turned down. Thus, there should be little of no correlation between absolute temperature and forcings, but there should be good correlation between the rate of change in temperature and forcings.
TWENTY YEARS.
http://lch.web.psi.ch/files/Publikationen/analytic/Eichleretal_GRL2009.pdf
Top down forcing from the sun regulates the NAO and IPO phase. Negative NAO and La Nina ENSO domination result from a solar decline which in turn takes twenty years to regulate global temperatures. Arctic sea ice volume also builds. Group sunspot number began the decline in 1990 and now twenty years later global temps have begun to decline. The modulation is caused by the sun’s solar wind and magnetic field and not TSI and is an intersolar cycle process.
The idea that the temperature of the earth will reach equilibrium in a few years is nonsense. We know that the ice caps of the earth will take many thousands of years to melt even if the temperature went up to 22C, which is the upper limit reached in the past 600 million years. While this melting is on-going, the earth has not reached equilibrium. It is possible that the earth has not reached equilibrium since the end of the last ice age, as the land masses are still rebounding from the weight of ice.
“In contrast, the Earth has warmed up considerably within this time period. This means that the Sun is not the cause of the present global warming.”
Yeah, this is incredibly dumb. Let’s say that you put a kettle of water on the oven. Then you turn the oven to a certain level. The water doesn’t reach that level instantly. It continues to heat even though the source reached its maximum almost instantly. Now all you have to do is consider the oceans as a very big kettle of water with a corespondingly big lag time.
Here is a chart of the sunspot trend. It’s a couple years out of date, but the idea still applies.
http://reallyrealclimate.blogspot.com/2008/07/20th-century-sunspot-trend.html
So, even though we topped out around 1960, the levels still remained fairly high. Up through about 2000, ocean heat was likely busy catching up to that high level. The leveling out since 2000 is an indication that the dropping solar level is finally having an effect.
And by the way, the correlation between sunspots and temperature has been very good for as long as we have had a sunspot count. To suggest that it was suddenly failing because transitions show a lag time is just absurd.
I agree with Solanki’s concern regards lag effects of the ocean, but much of the problem is due to inhomogeneities of how we measure temperatures and how past proxies measured temperatures thus our reconstructions. Many of the climate indices such as tree rings, intensity of glacial retreat and upper-limits of tree-line, migrations of cod, as well as high arctic temperatures all show higher activity in the 1930’s and 40’s. Many if not most of the average annual maximum temperatures show peaks between the 30’ s and 60’s followed by a cooling that parallels solar activity. The climatologists’ tree ring divergence problem where the tree rings suggest 50 years of cooling also follows the recent decline in solar. This is likely due to the fact the tree rings will be more sensitive to summer and maximum temperatures, while the current instrumental warming is driven by minimum and winter temperatures. Finally not only do winter temperatures over the south pole show declining temperature but temperatures over the North pole also show a decline as described In “Absence of evidence for greenhouse warming over the Arctic Ocean in the past 40 years” by JONATHAN D. KAHL*, DONNA J. CHARLEVOIX*, NINA A. ZAFTSEVA†, RUSSELL C. SCHNELL‡ & MARK C. SERREZE§. As the surface of oceans cool with the approach of winter the underlying stored temperatures come into greater play and thus most oscillations like the PDO and NAO are most influential during the winters.
The positive Pacific Decadal Oscillation PDO generates wind patterns that more frequently oppose the trade winds thus promoting more frequent El Ninos and fewer La Ninas. The switch between the El Nino and La Nina in the late 90’s generated average global temperature change of over .8 C that matches the entire century change. It has been demonstrated the positive PDO correlates with wind patterns that raised winter surface temperatures in Alaska due to both disrupting the winter and night time cold inversions and advecting warmer more southerly air into the Arctic. And Rigor 2002 has shown winds coming from the coldest part of Siberia created open water in the Arctic ocean during the winter and spring. Rigor suggested warming was caused by winds reducing ice that exposed warmer ocean water. Winter water is about -2C compared to air the is less than -25 C. Just the opposite of the belief that CO2 warmth was increasing reduced ice. Scott also demonstrated winds were reducing ice in the Hudson Bay.
Dormant trees will not be sensitive to those observed winter temperature increases, explaining the divergence problem between biological proxies and instrumental records. The trees are in better agreement with the sun. It is our method of measuring current temperatures that disagree. Briffa and other CO2 advocates, instead of questioning their own methods, have even argued and pubiished that trees are now less sensitive due to CO2, despite the fact that tree line has extended much further towards the north pole over the last 9000 years than at present. Somehow wanting us to believe the tree rings were representative during warmer earlier times but not now during slightly cooler times?
If we used a top down model that simply adds sunspots to a scaled PDO index, with a 20 year running average, that model generates a temperature curve that matches observed temperatures. This works because the PDO is a generalized proxy that incorporates changes in El Nino and wind patterns over the Arctic as well as teleconnections to the Atlantic. The diurnal and seasonal distribution of heat modified by ocean and wind circulation changes has created observed instrumental warming despite a general decrease in heat input from the sun. Such a top down model also suggests that with decreased solar and PDO going negative, that the next 20 years will be much colder.
Lady: “But the Danish scientist who found that all the coldest records were being deleted from the records, your graph of number of stations versus temperatures–now that is a plausible explanation that truly fits the data.”
Right. And in addition to that, the proxy records are simply not showing the kind of temperature increases for the last 50 years that the instrument records are showing.
“That doesn’t match the solar record from the 1940s onwards.”
Actually, it still does. Just think of the solar influence being modulated by ENSO.
Anthony, May I use your blog to tell a story I have wanted to put on the record for about 40 years; relating to the difference between getting the “right” answer, and getting the “correct” answer (terms which I will define). I was involved in an interntional project with the acronym MBFR – Mutual and Balanced Force Reductions. This was the idea that, at the height of the cold war, it would be an good idea to reduce the NATO and Warsaw Pact forces which faced each other across the border between East and West Germany. I am a Canadian, and worked for our Department of National Defence. Our Canadian politicians were very much in favor of this idea.
The miltary establishment was given the job of assessing how much risk would be involved if reductions were made. This was the same as asking the fox to guard the chicken house. The “right” answer was that any reductions would significantly increase the risk to NATO. The “correct” answer was that any reductions would significantly decrease the risk to NATO. One study was done by a sister organization in the UK, to the one I worked for. This study got the “right” answer; that there was a big increase in risk if reductions were made. I knew their methodology, and I knew where they had made a fatal and fundamental error. I went to talk to them about it.
Analyst to analyst, it took about half an hour for me to identify precisely where the error had been made. It then took about another half hour to convince my fellow analyst that I was right. Reluctantly he agreed that, indeed, their methodology could not solve the problem; that a fatal and fundamental error had, indeed, been made. But then came something I will never forget.
The Brit looked me in the eye, and said, very accusingly, “What the hell are you worried about? We got the right answer”.
Surely this is what is happening here. Solanki and Schuessler did a study and got the “right ” answer; the sun has had no effect on climate during the period when CAGW is supposed to be happening. They did not dig too deeply, but got their study published. Now Alex Rawls has queried their conclusions. There is a discussion going on, on Judith Curry’s blog, Climate Etc. about Qui custodios custodiat (If I have got this right). It seems to me that when it comes to CAGW, the scientific establishment has a lot ot answer for. Sarc on. As long as someone gets the “right ” answer, there is no need to ask whether they have got the “correct” answer. Sarc off.
FIG. 2 [Svensmark]: … The upper panel shows observations of temperatures (blue) and cosmic rays (red). The lower panel shows the match achieved by removing El Nino, the North Atlantic Oscillation, volcanic aerosols, and also a linear trend (0.14 ± 0.4 K/Decade).
Have I read this right. It seems Svensmark has found a correlation by removing the linear trend … as well as ENSO, NAO etc.
Isn’t the linear trend the thing we’re interested in? The fact that GCRs can explain everything apart ENSO, NAO, volacanic aerosols and the linear trend is interesting but it’s hardly a show stopper for AGW.
Part of the solar energy absorbed in the oceans is radiated back from surface layers, in the short term of days and months. It is the huge amount of energy stored further down which is in medium (years) or longer (decades) terms relatively stable and does not respond readily to solar cycles whatever mechanism may be considered.
To understand periods 1910-1945 (warming), 1945-1975 (cooling), 1980 – 2000 (warming) and 2000 – 2010 (cooling) it is important consider the sync and upwelling ocean regions. Important ones are located in the Pacific and Atlantic; as a consequence polar and subtropical jet streams will respond. Any change in the major ocean currents would result in climatic oscillations. These changes therefore are ‘drivers of the natural multi-decadal climate change’, as it is clearly demonstrated by correlation with the major climatic indices.
http://www.vukcevic.talktalk.net/PDO-ENSO-AMO.htm
If a long-term lag in equilibrium exists which is equivalent to the length of the Little Ice Age, then the global mean temp is about to roll over with a 300 hundred year long downslope. That would make the 20th Century Solar Max riding on top of the last of the crest from the time preceeding the Little Ice Age.
Nothing is settled.
@jim Cripwell.
Interesting story but the Solanki and Schuessler does not prove the sun had no effect during the period that CAGW is supposed to be happening. In fact, if anything, it negatively affects CAGW science, which talks about warming from the 1880s to present.
This paper does prove 3 things:
1. The sun does have an effect on climate (kind of seems obvious doesn’t it but the two graphs have excellent correlation – until the 1980s).
2. The effect of the sun on climate is greater than the CAGW crowd assumes (because it almost fully matches the temperature anomaly until the 1980s and if CO2 was a growing problem the graphs should diverge).
3. Something strange has happened to the temperature record (real or otherwise) since the 1980s.
I’m really interested to know why tree proxies and now sun effect diverge from the measured temperature record – both in the same direction – since the 1980s.
Further to my comment above, i.e.
John Finn says:
April 7, 2011 at 9:58 am
Svensmark’s FIG 2 simply seems to show the temperature fluctuations due to the solar cycle which are, as Leif Svalgaard has posted many times on this blog, ~0.1K (min to max). However, as we can see, there is no trend so that’s not the reasom n for the warming.
If you look at tree data the major period of northward or upward recruitment was not during recent times but during when solar activity was at it height. After that period trees growing within the shelter of the newly established recruits then show varying degrees of growth as the recruits altered the micro-climate. The major climatic change was in the early-mid 1900’s followed by the “divergence problem” suggesting cooling.
From Esper 2004 “Large-scale treeline changes recorded in Siberia”
Analysis of a multi-species network of western Siberian ecotone sites revealed pulses of tree invasion into genuine treeless tundra environments in the 1940s and 1950s and after the early 1970s… For western Siberia, the presence of relict stumps, nevertheless, indicates that this present colonization is reoccupying sites that had tree cover earlier in the last millennium.
A mid 20th century recruitment period, synchronous with the advance shown from the western Siberian network, is reported from central Sweden (1946–55) [Kullmann, 1981], northern Finland (1945–47) [Kallio, 1975], northern Quebec (1938–63) [Morin and Payette, 1984], and the Polar Urals (1940–55) [Shiyatov, 1992].
George Steiner says:
April 7, 2011 at 9:14 am
“I will say that there is not an equilibrium in the oceans or the athmosphere. This word should not be used. I just confuses the issue.”
You can’t talk about thermodynamics without using the word equilibrium. Don’t be silly.
Alec Rawls posted, “Under the GCR-cloud theory, high solar wind blows the clouds away…”.
No, it doesn’t, there is no direct action of the solar wind with clouds. A strong heliosphere could be said to ‘sweep more galactic cosmic rays away’ from the Earth. Fewer GCR means a small but significant reduction of cloud condensation nuclei and this reduces low altitude cloud cover a small but significant amount.
I suspect Rawls knows this but likes the shorthand reference, but it is both literally incorrect and misleading.
Dave Springer says:
April 7, 2011 at 6:11 am
The sun is in a grand maximum and plateaued in 1980. We already knew that. This is encyclopedic knowledge.
As Mark Twain said: ““It ain’t what you don’t know that gets you into trouble. It’s what you know for sure that just ain’t so.”
Solar activity in the mid 1800s and late 1700s was just as high. There is no “modern grand maximum”. http://www.leif.org/research/Eddy-Symp-Poster-1.pdf
Nicola Scafetta says:
April 7, 2011 at 7:04 am
I believe that there are several open issues that Solanki does not address such as for example: 1) ACRIM vs. PMOD TSI composite controversy
PMOD is affected by calibration problems [ACRIM has its own – different – problems]. There is no good evidence that TSI was any lower this minimum than during past ones. http://www.leif.org/research/PMOD%20TSI-SOHO%20keyhole%20effect-degradation%20over%20time.pdf
Steve from Rockwood and John Finn both note how Svensmark’s fitting of solar activity to temperature involves removing the trend. I take this as an indication that the high solar activity over the period he is looking at (from the late 50s to the present) caused an upwards temperature trend. If the temperature trend were not taken out, the ups and downs of the solar record would fall progressively below the ups and downs of the temperature record.
The implication seems to be that more heat was being poured into the oceans during the up-phases of the solar cycle than was lost during the down-phases, with no sign that this process stopped before the downturn in solar activity. That is, the ocean’s never did attain an equilibrium response to grand maximum levels of solar activity.
Alec Rawls says:
April 7, 2011 at 11:33 am
That is, the ocean’s never did attain an equilibrium response to grand maximum levels of solar activity.
There was no modern grand maximum.
Nicola Scafetta says:
April 7, 2011 at 7:04 am
ACRIM vs. PMOD TSI composite controversy
The degradation of PMOD has continued. Here is the latest data:
http://www.leif.org/research/TSI-Diff-PMOD-SORCE.png
The solar heating of the oceans is much more complex than most people realize. The solar radiation can penetrate to a depth of about 100 m for a ‘pristine’ ocean. The attenuation with depth follows Beer’s law. The sunlight is attenuated exponentially along the optical path, depending on the local attenuation coefficients and the wavelength. There are 5 major ocean gyres that re-circulate ocean water between the equatorial regions and higher latitudes. Near the equator, the diurnal mixing layer is quite shallow (nominally 50 m) and the solar heat gets trapped below these depths. As the water is transported through the equatorial parts of the gyres it gets ‘cooked’ by the sun. It can take about 6 months for the ocean water to cross the Pacific. This produces the warm ocean pools. These are huge thermal reservoirs – ~30 C surface temperatures and 25 C temperatures to depths of 100 or 150 m. Part of the warm water from these pools is transported to the Arctic where it provides heat for the ice melt/ice extent etc. The water transported south ends up in the Southern Ocean and re-circulates around all three S. ocean gyres (Pacific, Atlantic Indian).
There is no equilibrium on any time scale. The heating and cooling has to be described dynamically in terms of coupled rate equations. Each gyre has its own unique characteristics. Every few years, the subsurface heat stored in the Pacific ‘pops up’ and gives rise to the characteristic ENSO oscillations.
Small variations in the solar flux accumulate in the oceans. A 1 W.m-2 flux accumulated into a 100 m column of water over 1 year produces a temperature rise of 0.07 C. The ‘grand maximum’ produced an average increase in (top of atmosphere) solar flux of ~0.3 W.m-2 for 50 years. This long term change is hidden below the ENSO, PDO, AMO etc. oscillations.
Instead of arguing over correlations and equilibrium assumptions, run the real numbers. Solve the rate equations! At minimum determine six heat contents for the solar heating and coupling of 5 major ocean gyres and the S. Ocean. Anything less is just meaningless speculation. Also, a 100 ppm increase in atmospheric CO2 concentration can have no effect on ocean temperatures. The penetration depth of the long wave IR (LWIR) radiation from CO2 into the oceans is less than 100 micron. This change in LWIR flux is just lost in the noise of the wind driven surface evaporation. Sun, wind and water need no help from CO2 to set the Earth’s climate. The devil is in the details.