Guest post by Guillermo Gonzalez
I recently happened upon the SORCE/TIM website and decided to look up the plot of the full total solar irradiance (TSI) dataset (http://lasp.colorado.edu/sorce/data/tsi_data.htm#plots)
The SORCE mission began collecting TSI data in February 2003.
I was curious to see if the variations in the TSI had begun to rise yet, perhaps indicating a start to cycle 24. Visual inspection of the SORCE TSI plot showed just the opposite – variations continue to decline in amplitude. If cycle 24 has started, there are no signs of it in these data.
We can be a bit more quantitative if we examine, instead, a plot of TSI variance with time. I produced such a plot using the daily average TSI data provided on the SORCE web site.
The red data are variance values calculated at two-week intervals. The blue curve is the smoothed data calculated in the same way as smoothed sunspot numbers (basically a 12-month running average). Note, the vertical axis is plotted on a logarithmic scale.
To compare the recent TSI variance trend with the previous sunspot minimum, I looked up the ACRIM2 daily average TSI data at: http://www.acrim.com/Data%20Products.htm
These data are plotted on the same scale as the SORCE data. The smoothed data show a minimum TSI variance near the beginning of 1996, some months before sunspot minimum (October 1996). Notice that the minimum value for the variance during the 1996 minimum was about an order of magnitude larger than the present TSI variance.
The SORCE web site quotes long-term 1-sigma precision (relative accuracy) of their TSI measurements to be 0.001%/yr. This corresponds to a variance of 2 ´ 10-4 W2 m-4. However, the precision should be considerably better than this on the 2-week timescale that I selected for calculating the variance. Unfortunately, I have not been able to locate a quote for the estimated precision of the ACRIM2 measurements. It would be worthwhile to know if the minimum TSI variance of the previous sunspot minimum measured by ACRIM2needs to be corrected for the instrumental precision.
Guillermo Gonzalez writes on his background:
I’m an astronomer, though my present title is associate professor of physics at Grove City College, PA. I wrote a paper (in Solar Physics) with Ken Schatten back in 1987 on predicting the next solar maximum with geomagnetic indices. That was my only contribution on anything having to do with the Sun-Earth connection, but I also got a letter published in Physics Today in 1997 wherein I urged readers to takethe Sun-Earth climate connection more seriously.
These days most of my research is on extrasolar planets.
UPDATE: I received a suggestion for an overlay via email from Terry Dunleavy and I’ve worked one up below. This was done graphically. I took great care to get the two lined up correctly. Note however that the datasets span different lengths of time, as you can note on the two timescales I’ve included on the combined graph. The vertical scale matches exactly between graphs though. – Anthony
UPDATE2: Here is another graphical comparison of the two TSI variance graphs, scaled to have a matching X-axis and appropriately aligned side by side. – Anthony
[snip – The next person to mention SWINE FLU on this thread will be kicked off for 48 hours. STAY ON TOPIC – Anthony]
Understood
kevin roche (15:47:53) :
Unless the sun preferentially develops sunspots and associated phenomenon in certain locations
But it does! Both in a deep sense and in the following more trivial sense: suppose solar activity [as now] is really low and there is only big spot per year. That spot will develop at a given location and decay there, taking several months to die away. As it does, each time during a solar rotation that the spot area faces us, we’ll see enhanced emission. Like a lighthouse.
Smokey says:
By the way, it sometimes helps you get better comprehension of what is being said if you actually read more than one sentence. If you had read beyond that first sentence, you would have understood that the whole point of that article was to look at what the real world evidence from paleoclimate data is and then ask how it compares to what the models say. The conclusion that they reach is “the climate system is very sensitive to small perturbations and that the climate sensitivity may be even higher than suggested by models. “
Leif Svalgaard (15:22:48) :
…
I’m talking about this:
http://www.leif.org/research/TSI-SORCE.png
The red curve is the TSI actually observed at and by the Earth since 2003. The blue curve is what TSI looks like at 1 AU, but this is not what the climate system sees. It sees the red curve. Now, I do not expect [and cannot explain – perhaps you can] why the red curve has no effect, and the blue has.
—
I like your stated ´simple´ dilemma which even can start to be explored without detailed physics.
To start; I don´t fully understand Leif´s statement that the oscillating red curve (observed by the Earth) has no effect [on the climate system, I assume]. Please explain.
Let us put it this issue of the TSI this way: We receive a certain amount of “money” which varies during 11 years, up and down…but, suddenly, it lowers more than expected, so, in order to keep our current expenses, we have to begin taking some money from our “savings”(the seas), so these begin to cool down…
We, of course, hope that someday, in the near future, things will improve and our “income” will return to its current levels.
So, it is a matter of the “economics” (econos=house, greek) of energy, how it is received, how much (rather the same amount always), how much of it we save it, which are the ways to spend it, etc.etc.
Leif Svalgaard (15:22:48) :
[i]The red curve is the TSI actually observed at and by the Earth since 2003. The blue curve is what TSI looks like at 1 AU, but this is not what the climate system sees. It sees the red curve. Now, I do not expect [and cannot explain – perhaps you can] why the red curve has no effect, and the blue has. Explain and demonstrate quantitatively why that is in terms I [and others] can easily understand.[/i]
Leif it appears to me you are one suggesting the red curve has no effect. I merely suggested that the effect has not been measured and that the frequency of the cycle in question would have an effect on how much feedback you might receive from a given cycle.
Remove all the modifying factors then should not a TSI change of 1 over a 100 years equal a TSI change of 100 over one year? Is that well enough quantified?
The modifying factors could well change the amplitude of the net change though, with the higher frequency cycle not obtaining the same amplitude of the lower frequency cycle because of feedbacks extending into the next phase and moderating it.
I see that every day living at the edge of the Pacific Ocean. 50 miles inland the daily temperature range can be 60 degrees greater.
Seems to me the red curve annual cycle is already integrated into the climate system and may well explain some of the regular water cycles we see in the oceans. . . .some of which take years to play out and exhibit all sorts of frequencies or harmonics.
So in short I also believe the red curve has an effect. Its pretty hard to imagine how changes in TSI could have no effect. If you truly believe not perhaps you could explain how that would work. . . .some cosmic membrane that works like a water saving showerhead or something like that. . . .sounds rather cloudy.
Sideliner (17:00:39) :
To start; I don´t fully understand Leif´s statement that the oscillating red curve (observed by the Earth) has no effect [on the climate system, I assume]. Please explain.
In my simple-minded way, if I accept feedbacks to make 1 degree out of 1 W/m2, then I expect them to make 100 degrees out of a 100 W/m2. This clearly does not happen, so explain to me why not [and don’t just say that it doesn’t].
Adolfo Giurfa (17:03:57) :
Let us put it this issue of the TSI this way: We receive a certain amount of “money” which varies during 11 years, up and down…but, suddenly, it lowers more than expected, so, in order to keep our current expenses…
OK, we receive $13.61 at solar max and $13.60 at solar min…
Sideliner (17:00:39) :
To start; I don´t fully understand Leif´s statement that the oscillating red curve (observed by the Earth) has no effect [on the climate system, I assume]. Please explain.
In my simple-minded way, if I accept feedbacks to make 1 degree out of 1 W/m2, then I expect them to make 100 degrees out of a 100 W/m2. This clearly does not happen, so explain to me why not [and don’t just say that it doesn’t].
Adolfo Giurfa (17:03:57) :
Let us put it this issue of the TSI this way: We receive a certain amount of “money” which varies during 11 years, up and down…but, suddenly, it lowers more than expected, so, in order to keep our current expenses…
OK, we receive $1361.50 at solar max and $1360.25 at solar min…, and now all of the sudden we only got $1360.20, so we have to change our lifestyle…
Leif Svalgaard (17:29:28) :
Sideliner (17:00:39) :
To start; I don´t fully understand Leif´s statement that the oscillating red curve (observed by the Earth) has no effect [on the climate system, I assume]. Please explain.
Leif Svalgaard (17:29:28) :In my simple-minded way, if I accept feedbacks to make 1 degree out of 1 W/m2, then I expect them to make 100 degrees out of a 100 W/m2. This clearly does not happen, so explain to me why not [and don’t just say that it doesn’t].
—
I follow you if that was an immediate linear effect on temperature of any TSI change. But is this what we are discussing? Sorry, I am confused. Are we on the same ´timescale´page for this particular issue? Need to clarify that.
Due to the timezone diff I have to jump into horizontal soon, so I have not looked up the graphs; From top of my head – Isn´t the average global temperature slightly lower during the southern hemisphere summer, even if the TSI in that period is higher? Well, of course we know it is probably mostly due to the different ocean/land characteristics of the hemispheres.
Yet again in a simple minded way [and with a lot of if´s..]; What would the immediate temperature variations be if there was no TSI variation during the year? Similarily, if the TSI oscillation was shifted half a year with the highest peak during northern hemisphere´s summer? And subsequently the effect on longer-term climate for these cases?
The Facular Indications for SC24:
http://www.robertb.darkhorizons.org/DeepSolarMin3.htm
2nd graph as compared to 1913 http://www.robertb.darkhorizons.org/2008fac.JPG
Since July 2008, the cycle has been in a very low state in terms of white-light faculae. When the 1st quater 2009 data comes out, I will update the graph.
It really does look an order of magnitude weaker than 1913.
In my haste, oops.
The 1913 graph goes from zero to 500 on the Y axis.
The 2008 graph goes from zero to 450 on the Y axis.
I’ll fix it later.
Leif Svalgaard (15:31:24) :
George Gillan (15:14:59) :
Leif, you used my poor wording to dodge the question. So not ‘TSI’ but instead Received Solar Irradiance (I’m unsure of the official term), certainly affected by the Earth’s tilt. Nothing to do with the sun? Everything to do with the sun, of course. 🙂
I resent strongly the insinuation that I ‘dodged’ anything. The Globally Received Solar Irradiance has nothing to do with the Earth’s tilt, and summer/winter has nothing to do with the Sun. Perhaps this can explain it to you:
http://www.enchantedlearning.com/subjects/astronomy/planets/earth/Seasons.shtml
Leif, I apologize, I didn’t mean ‘dodge’ as strongly as it obviously came across. It’s obvious that I have failed to communicate effectively, for which I also apologize. I’ll make one last try and then drop the matter to avoid wasting your time:
I am not seeking to understand the earth’s seasons, I already do understand them. Of course, without the effect of the sun’s radiation, there would be no summers or winters as the hemispheres angle toward or away from the sun. What I am attempting is to offer the seasons as a comparison for the effects of received solar radiation as it varies. In northern hemisphere winter the NH effectively receives less solar radiation than in NH summer due to the more oblique angle to the sun. Is summer warmer than winter because:
a) Just the direct result of more solar radiation in the hemisphere.
b) More SR plus some feedback mechanism.
c) More SR plus some amplification mechanism.
d) Some other mechanism or combination.
If the increase in received solar radiation (on the hemisphere) is by itself inadequate to explain the increase in temperatures that occur in summer, then perhaps one or more other mechanisms are at work (locally, within the hemisphere). Presumably, the effect of those mechanisms can be estimated by accounting for the direct effect of the increased received solar radiation in summer and subtracting that from the total observed effect.
You have pointed out many times on this site that variations in globally received solar radiation (if I abbreviate as ‘TSI’ would that be correct?) are inadequate to explain climate variations over the course of sunspot cycles and beyond. I realize that some mechanisms exist globally that do not exist within a hemisphere, and that some mechanisms act on multi-year cycles but not within seasonal cycles. Still, some feedback mechanisms that are present on a global scale might also act within a hemisphere (and at a much smaller scale) during the seasons.
I was trying to lay that out as a possible bridge between some of the questions posted and your answers to them (which were not connecting with the questioners).
It seemed a much more obvious comparison at first, but it has turned out to be a long and tortuous road to communicate it. At this point I presume it will be of little or no help.
Sideliner, Leif is asking you a rhetorical question to see if you recognise what each represents. The irradiance at 1 AU has no bearing on Earth climate because Earth is not always at 1 AU from the Sun. The distance of the earth changes because our orbit is slightly elliptical. 1 AU is merely the average distance of the Earth from the Sun. When we are closer, we obviously receive more radiation from the Sun, and when further away, we receive less.
If we are furthest away from the sun AND polar precession has the north pole pointing away from the sun, AND solar emission is at a minimum, the Earth will receive the minimum possible irradiance. All these factors have an impact on the other line he was trying to draw your attention to and making you aware that the 1 AU irradiance line is really irrelevant.
Sideliner (17:58:18) :
I follow you if that was an immediate linear effect on temperature of any TSI change. But is this what we are discussing?
A change in TSI does produce a change in temperature. The formula is simple dT/T = 1/4 dTSI/TSI, so a 0.05% change in TSI produces a 1/4 * 0.05% = 0.0125% change in temperature T, or 0.036 degrees K. A 7% change in TSI produces a change of 7/4% of T = 5 degrees K, which might be of the right order [although it seems a bit high still] of the change due to the changing distance to the Sun. Now, people tell me that the 0.036K should be much larger because of feedback, and I ask why the 5K would also not be a lot larger because of feedback. I get a story about time scale, about ‘its already in the climate system’, etc. But that is, to me, not an explanation. I want to know which feedback mechanisms, how much they amplify as a function of time scale, basic stuff that will allow a straightforward engineering-type assessment of what is going on.
George Gillan (18:19:49) :
Is summer warmer than winter because:
a) Just the direct result of more solar radiation in the hemisphere.
Yes, just like it is warmer during the day than at night.
There are, of course, some second order effects [e.g. varying distance, different land/sea distribution, oceans currents, winds, etc], but to first order, I think it is as simple as that. If you think otherwise you will have to convince me.
The cold snap continues and has struck Victoria, Australia…
http://www.theage.com.au/national/polar-fronts-bring-mountains-the-white-stuff-20090426-ajem.html
Dear Anthony Watts… I’d like to bring your attention to the outbreak of Swine Influenza in Mexico and United States. It’s worth a special thread because WHO is selling the idea on an “atypical” epidemic which could turns out into a pandemic. I’m living in Mexico and I could answer some doubts about this epidemic.
PS. Ooops, forgot to mention this snow is 6 weeks ahead of the official start to the ski season in the region.
– – –
Ninderthana (19:44:50)
“These important linking factors negate the need to have a multiplicative factor to amplify the small changes in solar insolation.”
We need more of this kind of thinking.
– – –
Re: anna v
Thanks for pointing out the following paper:
Anastasios A. Tsonis, Kyle Swanson, and Sergey Kravtsov (2007). A new dynamical mechanism for major climate shifts. Geophysical Research Letters 34, L13705.
http://www.uwm.edu/~aatsonis/2007GL030288.pdf
The methodology is not as new as they claim, but it is good to see this application.
– – –
MA (04:04:36)
“And that means that we must prepare for that the butterfly CO2 can induce large effects, and don’t bother that much about the elephants in the room?”
Don’t forget about limits.
The problem is that sometimes too much faith is placed in ‘decompositions’, ‘corrections’, & ‘adjustments’, which can make it harder to extract finer roots. There’s a lot of mileage & important activity in fine roots. Trees depend on more than fat-root structure.
– – –
Joel Shore (07:08:11)
“It is strange that the very same people who are so skeptical of positive feedbacks that act on all forcings equally are so willing to believe in positive feedbacks that act selectively on the forcing that they want to believe is most important.”
Let’s not forget about limits.
“[Actually, whether or not there is a detectable temperature effect due to the 11-year solar cycle comes down mainly to the issue of damping. I.e., the changes in forcing from min to max of the solar cycle is enough to cause a detectable change in temperature with our current estimates of climate sensitivity if it happens slowly enough…but it is not clear whether these changes are detectable once the damping effects associated with the frequency of these variations in factored in…and particularly when trying to separate this from other climate variability factors.]”
This assessment seems based on cherry-picked investigative methodology.
– – –
Glass shatters …
Bridges collapse …
Micky C (MC) (06:36:54)
==
“[…] suddenly starts oscillating at an acoustic frequency […]
The onset occurs very quickly […]
The key is that the white noise can […]”
“[…] start to vibrate coherently and can no longer maintain the broadband energy to oscillate as a background. Hence acoustic waves appear.”
“Interestingly, longer oscillations can be excited by shorter oscillations and vice versa.”
==
Very refreshing to see awareness of ^this magnitude.
– – –
Re: Steve (07:48:06)
hilarious.
& interesting article – thanks
Re: Alan the Brit (09:01:06)
good commentary on this
– – –
Maurice Garoutte (08:32:27)
“If indeed fewer sunspots, cause more clouds […]”
If it was such a straight, linear relationship …
– – –
Leif Svalgaard (15:31:24)
“The Globally Received Solar Irradiance has nothing to do with the Earth’s tilt […]”
This would be an interesting (but not easy) generalization to challenge ….
– – –
Bill Hunter (14:49:47)
“Maybe if the southern hemisphere were the mirror image to the northern hemisphere maybe we could compare the temperature of Moscow North to Moscow South and know what you are talking about.”
^This was a clever comment.
– – –
— Robinson (03:07:34) —
“So, given that the oceans have a vastly greater heat capacity than the atmosphere, does anyone know what the “damping” effect (lag) may be on temperature/climate? I’m assuming there must be one; perhaps a few years, perhaps a decade or so.”
— ralph ellis (04:36:24) —
“Prof Landscheidt says 7 or 8 years.”
There are sensible arguments suggesting multiple (i.e. a range of) timescales (reaching up into the thousands (of years)) …with plenty of non-stationarity.
– – –
Bill Hunter (17:18:35)
“Seems to me the red curve annual cycle is already integrated into the climate system and may well explain some of the regular water cycles we see in the oceans. . . .some of which take years to play out and exhibit all sorts of frequencies or harmonics.”
Interesting – & tricky to investigate, particularly in the sociological context of (partially-misguided) undying, widespread beliefs about decompositions (particularly diurnal & seasonal ones), which can have a blinding effect, as mentioned above.
– – –
Carsten Arnholm, Norway (04:06:26)
“We know that the sun’s magnetic field varies much more than TSI. If Svensmark is right about magnetic fields, GCR and cloud coverage …. ?”
This is another one of these “elephant in the room” scenarios. Based on the various comments I see regularly posted about GCR/cloud theories, I have to wonder if some of the people [not Carsten] posting are aware of a more dominant factor: dewpoint.
….and to be clear: I’m not suggesting GCRs have no effect on cloud formation ….but my impression is that some will benefit from thinking about where/how GCRs fit into pictures like the following:
http://www.ldeo.columbia.edu/~kastens/curriculum/BRF/water/rain/Rain1.GIF
http://en.wikipedia.org/wiki/File:Dewpoint-RH.svg
– – –
kevin roche (15:47:53)
“Unless the sun preferentially develops sunspots and associated phenomenon in certain locations […]”
Solar scientists refer to them as ‘active longitudes’. The sun’s average rotation period (as viewed from Earth) at the solar equator is ~27 days. (I like Leif’s lighthouse analogy.)
There is plenty of literature on the subject – very interesting – lots of controversy in recent years since a few solar scientists [who Leif suggests occupy a parallel universe] have taken the stand that some very important (& very basic) things have been ‘overlooked’ for many decades.
The most vocal opponents at least concede that there is merit in investigating active longitudes via twisted-reference-frames since the sun’s convective zone exhibits differential rotation (slower towards the poles).
As for the dominant ~27 day signal (statistically significant even in the traditional, untwisted frames), no one appears to be disputing that. The first harmonic (~13.5 days) also shows up prominently in some indices.
Leif (& Wilcox) published an important paper in 1976 that also shows a clear 28.5 day signal in HMF structure, which exhibits intermittency related to the solar cycle. (Note: This is roughly the period of solar-core rotation.)
A variety of studies point out north-south asymmetries in features such as the exact period & persistence of signals.
– – –
Frank K. (05:06:10)
“I believe the statements “Modern technology cannot, however, predict what comes next.” and “No one fully understands the underlying physics of…” can aptly be applied to other areas of science e.g. numerical climate modeling…”
…. and economics. Solar physics, climate science, & economics have a lot in common. (Check on the nature & details of disputes in the literature – plenty of discord & paradox.)
– – –
Basil (05:59:43)
“With a moving average, you want data on either side of the current point.”
There are contexts in which centering moving-averages on points other than window-mid-points is sensible, but any such deviation from convention is best pointed out assertively (along with rationale).
Beware the pervasive use (some would say misuse) of the term “running” as though it is synonymous with “moving”. There is no stopping this train, so the dictionary has to bend accordingly – and we all have to read carefully to discern (&/or infer from context) what is actually meant each time we encounter the terms.
– – –
Adolfo Giurfa (16:03:01)
“Problem is…they believe in a Goddess, GAIA, and their most exalted preaching leader is HIM, the unnamable , that fatty alien who came from nowhere and who will take all their followers to a still unknown planet free of CO2.
Comments like ^this, particularly when they appear in bold, do little for the image of WUWT.
– – –
Re: Geoff Sherrington (04:36:50)
A very interesting post – thank you Geoff.
BTW, for those who have asked about the epidemic, viruses are sensible to UV even when they are not cells, because they have nucleic acids (RNA and DNA) and enzymes.
The outbreak in Mexico has been the product of negligence from the federal Health authorities in Mexico.
H1N1 is not a “new” virus because it appeared for the first time in Oregon in 1976. The virus shifted (jumped) from swine to humans due to continuous and prolonged contact between humans and pig cattle.
The virus is sensible to antiviral therapy. The disease doesn’t kill people, but the complications generated by deficient medical attention.
A vaccine exists, even though the CDC and WHO has decreed it wouldn’t work.
>>Look, the fact is that the W/m^2 change in forcing from
>>the solar variations is considerably smaller than the forcing
>>due to changes in CO2 levels. In order to make claims that
>>changes in the sun are still the dominant factor in the climate
>>over the last half century,
Where is the evidence that CO2 forces warming? – all I see is CO2 following warming, the Sun forcing CO2 levels.
Conversely, while the visible spectrum of the Sun has not varied a great deal, the magnetic flux has.
http://wattsupwiththat.files.wordpress.com/2008/10/solar_ap_index_10062008.png
http://www.appinsys.com/GlobalWarming/GW_SimplifiedNutshell_files/image002.jpg
There are many routes by which these variations in magnetic flux can effect climate on Earth.
.
Leif 18:20:55
I wonder if the feedback to the 5C warming just gets started when it is halted and reversed by the change of the season. In other words, it’s a process which gets abrupted every six months. Clouds certainly could be the intermediary, and since the feedback which would give too much sensitivity keeps getting stopped, we don’t see that signature.
============================================
cool…………….
kim (19:11:04) :
[…]since the feedback which would give too much sensitivity keeps getting stopped, we don’t see that signature.
All this is just hand waving. Feedbacks can be quantized and formalized, so many degrees for so many watts on this and that time scale. If they cannot then it is just worthless mumbo jumbo, or worse: derived by backwards and circular arguments: lemme see, how much ‘feedback’ do I need to account for this or that…