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
MalagaView (03:52:31) :
I am left wonder what is the definition of a “durable sunspot”….
Especially when i can still see yesterdays “non-durable” tiny sunspot while the “sun remains blank”……
Yeah, someone is struggling with some concept here. A good criterion for a ‘real’ sunspot [which endures for a few days] is if there is a penumbra. Tiny Tim’s don’t have any and probably should not be counted. On the other hand, if there are several together in a group, then there is an argument for counting them. This problem goes back 150 years. Rudolf Wolf, the inventor of the sunspot number advocated not counting the smallest spots or pores, while his assistant and successor, Alfred Wolfer, voted for counting everything he could see, small or large. Wolfer won that argument by Wolf eventually dying. Today people follow Wolfer, but multiply the count by 0.6 to make it more compatible with Wolf’s historical series. The 0.6 factor may not be correct [is too large, perhaps 0.5 would be better].
Dell Hunt, Michigan (04:58:24) :
So then you do the math. Using the numbers from the report (see link below) how much of that energy is trapped as the atmosphere expands vs contracts?
Since the energy absorbed depends on the number of molecules in the atmosphere it doesn’t matter if the atmosphere expands or contracts. And the number of molecules in the upper atmosphere is so small that the tiny, tiny amount of heat they ‘trap’ has no consequence for our climate.
Yes, Leif, you are right, the Tiny Tims surely have no penumbra, and the spots are so weak that the definition of umbra is sorely tested.
The apparition today is of a sunken spot, just visible below through a fog.
Thank you.
I will again try to project today.
Is that a sc23 spot right now? I can’t remember whick color leading is what. I should write it down.
“Since January, these SC23 lookalikes have been popping up. I say lookalikes because at first they were justified as reversed SC24’s. After a steady diet of them, they don’t look quite like the exception rather than the rule.”
It’s amusing to watch our Lights distractedly shouting at us “All is well, all is well! The Sun is behaving normally.”
All the while, they are frantically triangulating(count this one, not that), positioning themselves to pounce at the first inkling of just how the rules may have changed.
The funny part is the bag of grant-gold they vie for has a ghastly hole.
John Finn (17:25:56) :
I think I must be missing something.
TSI appears to be about 0.05% lower than it was 5 years ago – and this is supposed to cool the climate.
How exactly?
==========
Well lets do some simple calculations:
The Mean Surface Temperature of the Earth is quoted to be 288 degrees Kelvin.
[ see http://www.asi.org/adb/02/05/01/surface-temperature.html ]
The average albedo of Earth is 0.37
i.e. 63.00% of incoming solar energy contributes to warming
[ see http://www.asterism.org/tutorials/tut26-1.htm ]
So based on these two figures I calculate:
1) the Earth receives 457.14285 degrees Kelvin from the sun
2) the Earth deflects 169.14285 degrees of the input via the albedo effect.
Now if the output from the sun drops by 0.05% then we will only receive 456.91428 degrees Kelvin.
The albedo effect will reflect 169.05828 degrees of this input.
And the average temperature of the earth will drop to 287.85600 degrees Kelvin.
Thus a TSI change of 0.0005 probably causes a 0.144 degree Kelvin drop in temperature.
Now the key point is what happens to albedo effect with a drop in temperature.
Basically the polar caps will expand slightly and the temperate zone will shrink a bit.
So we get more ice and less trees in Canada for example.
This means that the albedo effect will amplify this drop in temperature by reflecting more heat. So perhaps the albedo effect increases by 0.06% and now the total temperature drop has become 0.41815 degrees
So now we get more ice and less trees in Canada again….
And so the small cooling cycles continue and the ice age slowly advances until
1) The albedo effect stops amplifying the cooling change as the cooler zones get nearer the equator i.e. ever decreasing increments reach a finate limit
or
2) The sun wakes up and starts pumping out more heat…
So what I am trying to say is that A LITTLE CAN GO A LONG WAY in climate terms.
MalagaView (13:18:46) :
John Finn (17:25:56) :
“TSI appears to be about 0.05% lower than it was 5 years ago – and this is supposed to cool the climate.
How exactly?”
Well lets do some simple calculations
Your calculation is not quite right [too complicated]. Here is a simpler way:
dT/T = 1/4 dS/S where T is temperature and S is solar irradiance. the equation automatically takes into account albedo, gray body issues, and greenhouse effect. So dS/S = 0.05% means dT/T = 0.0125%, applied to T=288K, yielding 0.036K. Quite small and insignificant. To pump that up to what your preferred effect is, one can apply a ‘feedback’ factor to fit.
MalagaView (13:18:46) :
Well lets do some simple calculations:
It’s ok, thanks, I know what temperature change results from a 0.05% reduction in TSI and as Leif’s calculations show, it is considerably less than the temperature fluctuations due to natural variability. Your argument implies high climate sensitivity which, funnily enough, is exactly the argument put forward by the AGW proponents.
PS Did you not read Leif’s posts on earth’s orbit and the 7% variation in solar insolation between January and July.
Solar modulated cosmic rays causing increased ice in Antarctica
“Increased growth in Antarctic sea ice during the past 30 years is a result of changing weather patterns caused by the ozone hole according to new research published this week (Thurs 23 April 2009). …
Using satellite images of sea ice and computer models the scientists discovered that the ozone hole has strengthened surface winds around Antarctica and deepened the storms in the South Pacific area of the Southern Ocean that surrounds the continent. This resulted in greater flow of cold air over the Ross Sea (West Antarctica) leading to more ice production in this region.” “Increasing Antarctic Sea Ice Extent Linked to the Ozone Hole”
“New research has found that despite climate change concerns, the amount of ice may actually be increasing across much of Antarctica.
Ian Allison, head of the Australian Antarctic Division’s ice, ocean, atmosphere and climate program, says outside of western Antarctica, ice levels are remaining steady or possibly increasing. …
“In east Antarctica there may be a slight increase due to increased snow fall.”” “Ice cover ‘increasing in east Antarctica'”
http://heliogenic.blogspot.com/2009/04/solar-modulated-cosmic-rays-causing.html
I am in doubt if the science behind the linked article is aimed to explain the growing Antarctic Icecap without undermining the AGW/Climate Change doctrine.
If this is the case it is yet another canard.
Re: Phil. (22:40:44) & (22:59:51)
Your focus & concerns may not match the focus & concerns of others in this thread. There is more than one dimension to the economic/political/climate/solar-science crisis.
WUWT is a great site and it would be an order of magnitude better if the moderators blocked the comments that get personal.
Reply: We try. Feel free to point out anything we miss. We often scan quickly, approving dozens of posts at a time. Remember, it’s volunteer work. Where’s my orange juice? ~ charles the moderator
Re: Phil. (22:59:51) :
“So you don’t know the answer…..”
The question was as simple as asking if 1+1=2.
Then a string of badgering for compliance.
Adds up to pollution of this thread.
Paul Vaughan (17:18:28) :
The question was as simple as asking if 1+1=2.
Then a string of badgering for compliance.
Adds up to pollution of this thread.
You could decrease the pollution by simply answering my question.
charles the moderator:
“Remember, it’s volunteer work.”
This I did not know – thank you for sharing this comment.
Phil. (22:40:44) :
“[…] red herring […] in effect the mean free path is so large that the surface will be effectively Euclidean […]”
This does not relate to the point I was raising.
Paul Vaughan (17:18:28) :
The question was as simple as asking if 1+1=2.
Then a string of badgering for compliance.
Adds up to pollution of this thread.
You could decrease the pollution by simply answering my question.
Let me add a polite clarification:
You were challenging a specific statement of mine, without telling me what the nature of the challenge. Since you will not answer my question, perhaps I could politely ask you to withdraw the challenge. Or tell me why you do not wish to withdraw it [and maybe even what it was].
Phil. (22:59:51)
“Posts from real scientists like Leif are welcome however.”
While the privilege of participating in this forum is not restricted according to profession or career-stage, it seems sensible for participants to expect a degree of civility from other participants.
Climate is a concern for all of society – and at present the trust between the public and the science community has been partially broken (something many saw coming years ago).
Paul Vaughan (17:04:49) :
economic/political/climate/solar-science crisis.
economic [yes]. political [maybe], climate [no] crisis, and similarly no solar-science crisis. On the contrary, solar science has never looked brighter. The sun is entering a quiet period [as predicted – with the usual dissenters, there always are], new powerful solar instruments are coming online soon [SDO, AST]. Computing power has increased to the point where we can begin to model realistically. New theoretical tools in heliosesimology are being developed. We are getting a better understanding of the meaning [as well as improved calibration] of our long-term historical data. This is a golden age for solar research. No crisis at all.
Leif,
Can you direct me to more info on:
dT/T = 1/4 dS/S where T is temperature and S is solar irradiance. the equation automatically takes into account albedo, gray body issues, and greenhouse effect.
I looked on your site a bit but didn’t find anything (probably due to ignorance). Thanks.
Oh and Leif, you are mentioned in the June issue in Sky and Telescope in a letter to the editor (page 10)… 🙂
charles the moderator
You are doing a good job in keeping a level of the discussion. You cannot be expected to keep us on topic 🙂 Like most here I like to see what Leif is saying about things in general , but I had forgotten what this challenge was !
Had to look for it in the interest of the rest of the readers of this thread:
Leif Svalgaard (12:48:56) :
Paul Vaughan (12:30:35) :
“Leif Svalgaard (07:59:19)
“The important result is that geomagnetic activity in 1845-1875 is comparable to the past 30 years, while temperatures are not.”
Paul: “I have to challenge you on this Leif. We are not dealing with a simple bivariate system.”
Leif: “I’m not sure what you are challenging. I was only making a statement about the data, not its interpretation. Are you challenging my statement that temperatures the past 30 years are not comparable to what they were in 1845-1875?”
In my view, Paul wants to say that searching for a correlation in the time spectra of geomagnetic activity and temperature is not a simple thing as there are more variables than obvious entering which might mask correlations. Or maybe that the geomagnetic activity of last century is a guess work that depends on a lot of variables. Both interpretations are trivial imo.
We work with the data we are given. General challenges are meaningless. If we dispute the data we have to put some elbow grease and show where the data is wrong.
Otherwise the thread has deteriorated to a game of trivial pursuit :).
jonk (12:18:26) :
Is that a sc23 spot right now? I can’t remember whick color leading is what. I should write it down.
Even South ReVerses.
R=Red (White on MDI Magnetogram)
V=Violet (Black on MDI Magnetoram)
Black leads on this spot (Violet or V on Mt. Wilson Drawing)
BV , so the spot is SC23 (odd)
If the were SC24 (even cycle) it would be RV, or White on the MDI Magnetoram leading.
Remember SC Even South ReVerses in case you can’t remember which is which.
The actual behavior (as far as the current data shows) of Ice Ages is a rapid plunge to, and a very slow climb out of.
A normal solar cycle ramp is fast to max, and 1/2 rate to min.
Opposite leaning slopes.
Has the Earth spent more time in the Ice Ages, or Interglacials?
Somehow, nature is trying to tell us something, whether it can be equationed out or not.
alphajuno (21:28:02) :
Oh and Leif, you are mentioned in the June issue in Sky and Telescope in a letter to the editor (page 10)… 🙂
I hope it was positive.
About the equation. This is textbook stuff that you may find many places on the internet. But, better than that, we can derive from basic physics. The starting point is that what the Earth radiates must equal what it gets from the Sun, then we can use Stefan-Boltzmann’s law: S = a T^4, saying that the radiance S is proportional to the fourth power of the temperature. For a black body the constant is a = 5.67E-8. For a gray body, it is another constant [‘a’ multiplied by the ’emissivity’ of the body which is less than 1 for a gray body], but it is still a constant. For a given albedo A, you have to multiply by (1-A), which is still a constant [the albedo can vary with wavelength so we are talking about the ‘effective’ or average albedo]. Then you have to divide by 4 because the Earth is a sphere and not a disk, but in the end you just end up with the same law S = a T^4, except the constant a now incorporate the gray body emissivity, the albedo, and the sphericity of the Earth. In the penultimate step we differentiate: dS = a (4 T^3 dT), or by dividing both sides by S [on the left] and aT^4 (which is the same on account of S = aT^4) [on the right]: dS/S = 4 dT/T, and finally by rearranging: dT/T = 1/4 dS/S. You can see that the constant conveniently disappears. We can multiply both sides by 100, then we have percentages. The final step is also important, because we calculate the percentage of the actual T which is augmented by 33K by the greenhouse effect [or whatever you wish to invoke to account for the Earth being 33K warmer than from radiation equilibrium alone]. So using T = 288K takes care of the ‘greenhouse’ effect. And there you have it.
Melbourne, Victoria, Australia had it’s coldest morning today since 1957, 2.7c. Rising CO2 and record lows in both hemispheres. Hummm…..
– – –
Re: anna v (22:23:07)
You’ve picked up on some of what happened, but not the lead-up series of comments that triggered the challenge, nor my immediate (right off the bat) suggestion that we leave the topic for another day to avoid going off-topic.
The other point I would add is that we are all volunteers. The minute personal attacks start appearing, responding is no longer just a matter of addressing the science; other factors begin affecting decisions about what constitutes an appropriate response. (Note: A response is not necessarily a reply.)
– – –
Phil.: Despite your ill-spirited introductory ambush, your apparent lack of respect for my dozen years of formal post-secondary education, your inappropriate revelation of personal information about one of your former students, and your offensive innuendo about the social sciences, I would make an effort to turn our exchange towards something constructive if I knew your area of expertise; I consider it likely that you possess unique knowledge that will be of interest to readers, including myself.
– – –
Leif Svalgaard (19:06:49)
“[…] we can begin to model realistically […]”
I will believe this when I see it, but I both acknowledge & appreciate the value of efforts. Science funding needs to be increased by at least 2 orders of magnitude for all sorts of reasons, not the least of which is the sustainable defense of civilization.
FYI: I continue to read the solar science literature. It is fascinating.