Geomagnetic Forcing of Earth’s Cloud Cover During 2000-2008?
Guest post by Roy W. Spencer, Ph. D.
I’ll admit to being a skeptic when it comes to other skeptics’ opinions on the potential effects of sunspot activity on climate. Oh, it’s all very possible I suppose, but I’ve always said I’ll start believing it when someone shows a quantitative connection between variations in global cloud cover (not temperature) and geomagnetic activity.
Maybe my skepticism is because I never took astronomy in college. Or, maybe it’s because I can’t see or feel cosmic rays. They sound kind of New Age to me. After all, I can see sunlight, and I can feel infrared radiation…but cosmic rays? Some might say, “Well, Roy, you work with satellite microwave data, and you can see or feel those either!” True, but I DO have a microwave oven in my kitchen…where’s your cosmic ray oven?
Now…where was I? Oh, yeah. So, since I’ve been working with 9 years of global reflected sunlight data from the CERES instrument flying on NASA’s Terra satellite, last night I decided to take a look at some data for myself.
The results, I will admit, are at least a little intriguing.
The following plots show detrended time series of monthly running 5-month averages of (top) CERES reflected shortwave deviations from the average seasonal cycle, and (bottom) monthly running geomagnetic Ap index values from the NOAA Space Weather Prediction Center. As I understand it, the Ap index is believed to be related to the level of cosmic ray activity reaching the Earth. (I will address the reason for detrending below).
Note that there is some similarity between the two plots. If we do a scatterplot of the data (below), we get an average linear relationship of about 0.05 W per sq. meter increase in reflected sunlight per 1 unit decrease in Ap index. This is at least qualitatively consistent with a decrease in solar activity corresponding to an increase in cloud cover.
(I’ve also shown a 2nd order polynomial fit (curved line) in the above plot for those who think they see a nonlinear relationship there.)
But just how big is this linear relationship seen in the above scatterplot? From looking at a 70-year plot of Ap data (originally from David Archibald), we see that the 11-year sunspot cycle modulates the Ap index by at least 10 units. Also, there are fairly routine variations on monthly and seasonal time scales of about 10 Ap units, too (click on image to see full-size):
When the 10 Ap unit variations are multiplied by the 0.05 scale factor, it suggests about a 0.5 W per sq. meter modulation of global reflected sunlight during the 11 year solar cycle (as well as in monthly and yearly variations of geomagnetic activity). I calculate that this is a factor of 10 greater than the change in reflected sunlight that results from the 0.1% modulation of the total solar irradiance during the solar cycle.
At face value, that would mean the geomagnetic modulation of cloudiness has about 10 times the effect on the amount of sunlight absorbed by the Earth as does the solar cycle’s direct modulation of the sun’s output. It also rivals the level of forcing due to anthropogenic greenhouse gas emissions, but with way more variability from year to year and decade to decade. (Can anyone say, “natural climate variability”?)
Now, returning to the detrending of the data. The trend relationship between CERES reflected sunlight and the Ap index is of the opposite sign to that seen above. This suggests that the trend in geomagnetic activity during 2000-2008 can not explain the trend in global reflected sunlight over the same period of time. However, the ratio of the trends is very small: +0.004 Watts per sq. meter per unit Ap index, rather than -0.045. So, one can always claim that some other natural change in cloud cover is overpowering the geomagnetic modulation of cloudiness. With all kinds of climate forcings all mingled in together, it would be reasonable to expect a certain signal to emerge more clearly during some periods, and less clearly during other periods.
I also did lag correlation plots of the data (not shown), and there is no obvious lag in the correlation relationship.
All of this, of course, assumes that the observed relationship during 2000-2008 is not just by chance. There is considerable autocorrelation in the reflected sunlight and geomagnetic data, which I have made even worse by computing monthly running 5-month averages (the correlation strengths increased with averaging time). So, there are relatively few degrees of freedom in the data collected during 2000-2008, which increases the probability of getting a spurious relationship just by chance.
All of the above was done in a few hours, so it is far from definitive. But it IS enough for me to keep an open mind on the subject of solar activity affecting climate variations. As usual, I’m just poking around in the data and trying to learn something…while also stirring up some discussion (to be enjoyed on other blogs) along the way.
UPDATE (12:30 p.m. 10 December 2009)
There is a question on how other solar indices compare to the CERES reflected sunlight measurements. The following lag correlation chart shows a few of them. I’m open to suggestions on what any of it might mean.
“Correlations are easy to come by. Physical causation and understanding are much harder.”
Are you saying that their work isnt so badly? I mean, you admit that they found a correlation? If so, their work must be on the table, if i understood well.
If that correlation exists so could be a possible link between low magnetic solar with Earth. Or not. Maybe we dont know how, but if that correlation isnt bogus, I should put their work in the table. To understanding how that correlation works, if exists at all.
What I mean is, if the velocity of the rotation changes all the earth, perhaps that velocity changes it all. Solids, liquids and gases. I dont know if we have some works on that subject but if atmosfere lags changing the velocity some afect will have in air circulation. As the water. If so, is possible that correlation and maybe, I stress, maybe in temperatures. Or could be only an effect of other cause. But I dont like to put away something that isnt bogus. Perhaps is an mere effect. Maybe not. But I cant leave and forget. Isnt good policy.
But I sustain. If their work isnt bogus I still count with that. Is my point of view.
But thanks for that information. I still need to read more. 😉
PJMM (16:34:52) :
Are you saying that their work isnt so badly? I mean, you admit that they found a correlation? If so, their work must be on the table, if i understood well.
My criticism of their correlation was that it was cherry picked and not statistical significant. If you have a physical explanation, you can get away with less significance as the correlation is not to prove the relation, but to confirm it. The illustrate the difference: if I have a physical theory and mechanism and based on that I predict that it should rain tomorrow and it indeed rains, that may be taken as a confirmation. But without a mechanism, a single example doesn’t prove anything. You can ‘scale’ that up, to two examples, three, ten, a hundred, a million, etc. At a certain point, the correlation cannot be denied, even you don’t know the mechanism.
Leif Svalgaard (06:56:41) :
Our ‘opponents’ capitalize on the nonsense being spouted. It is harder to take us seriously as long as we pander to such pseudo science…
Ah, normal service is resumed.
Welcome back Leif. 🙂
It’s great you’ve decided you’re one of us.
It’ll be even greater when you stop behaving like one of them.
Fitzy (12:23:37) Right. We are living in interesting times, as those of Galileo. The Dominicans monks of the Inquisition now order: “delete emails”, “hide the decline” and so on. Funny indeed, the disappearence of dinausaurs like CRU, the sacrosant IPCC, up to such Ragendra Pachauri who looks like the the popes of those times, fortunately nature cleanses itself in a self healing process.
PJMM (08:47:56) : As a layman of course… like countless laymen like Thomas Alva Edison, etc. The less prejudice the more chance to see the light. He who believes knows everything knows nothing.
The parable of the camel and the eye of a needle refers precisely to this.
tallbloke (17:19:53) :
It’s great you’ve decided you’re one of us.
It’ll be even greater when you stop behaving like one of them.
Comments on my personal behavior are not called for. You are also suggesting that I’m a fraud like ‘them’.
In my professional opinion the stuff I referred to is pseudo-science. You can turn it into science by doing a proper analysis [and even submitting to review in a journal]. Proper science can still be wrong. But there are well-known and accepted ways of deciding this.
A note to other commenters – such as tallbloke
Treat Dr. Svalgaard with a measure of respect in discussion, or I’ll boot you off. Personal attacks are uncalled for. Penalty box next.- Anthony
Re: Leif Svalgaard (14:05:00) & (14:13:05)
I acknowledge your generous contribution. Thank you.
Paul Vaughan (18:40:43) :
Re: Leif Svalgaard (14:05:00) & (14:13:05)
I acknowledge your generous contribution. Thank you.
If you find it useful, let us know what you find.
P.S. It is possible [with somewhat greater error] to get these values back to the 1840s. The basic method is a relationship established using the past 45 years of spacecraft data: A ~ BV^2, where A is geomagnetic activity, B is the magnetic field strength in near-Earth space and V is the solar wind speed. B can also be estimated from other geomagnetic data, allowing us to estimate V from V ~ sqrt(A/B). Because of the sqrt, the error is relatively small.
Thank you Dr. Spencer.
“The illustrate the difference: if I have a physical theory and mechanism and based on that I predict that it should rain tomorrow and it indeed rains, that may be taken as a confirmation.”
Yes, I understood your point. My point is, maybe some explanation to that correlation could be find in the future. Maybe. Maybe not.
I was thinking in other problems. Thats why I asked if that work was bogus.
Thanks a lot.
Dr. Svalgaard
, was just perusing your research paper site. Am I right in thinking that your presentation on Wolf, states that the Sun was not more active in the first half of the 20th century as compared to the last half? I ask this, as this is a claim that I have been shown on the http://www.Skepticalscience.com blog. in relation to proof that CO2 is the driver of the late century warming.
{quote} Solar activity has shown little to no long term trend since the 1950’s. Consequently, any correlation between sun and climate ended in the 1970’s when the modern global warming trend began{end quote}
thanx
Sorry, forgot the link to the whole article
http://www.skepticalscience.com/solar-activity-sunspots-global-warming.htm
Anthony Watts (18:41:25) :
A note to other commenters – such as tallbloke
Treat Dr. Svalgaard with a measure of respect in discussion, or I’ll boot you off. Personal attacks are uncalled for. Penalty box next.- Anthony
Respect is a two way street. You can’t demand it, you earn it.
I like even-handedness. If you were also to ask Dr Svalgaard to treat others with a measure of respect in discussion, as Charles the moderator has found it necessary to do in the past, that would be very welcome.
I was discussing some ideas with Paul Vaughan (and asked him if we could move it off site) when Dr Svalgaard made his unwarranted attack.
An article in the UK Independent today is interesting:
“Could the Sun play a greater role in recent climate change than has been believed? … No living scientist has seen it behave this way. There are no sunspots. ”
“Although at solar maxima there are more sunspots on the Sun’s surface, their dimming effect is more than offset by the appearance of bright patches on the Sun’s disc called faculae – Italian for “little torches”. Overall, during an 11-year solar cycle the Sun’s output changes by only 0.1 per cent, an amount considered by many to be too small a variation to change much on earth. But there is another way of looking it. While this 0.1 per cent variation is small as a percentage, in terms of absolute energy levels it is enormous, amounting to a highly significant 1.3 Watts of energy per square metre at the Earth. This means that during the solar cycle’s rising phase from solar minima to maxima, the Sun’s increasing brightness has the same climate-forcing effect as that from increasing atmospheric greenhouse gasses. There is recent research suggesting that solar variability can have a very strong regional climatic influence on Earth – in fact stronger than any man-made greenhouse effect across vast swathes of the Earth. And that could rewrite the rules. ”
Full article at:
http://www.independent.co.uk/news/science/the-missing-sunspots-is-this-the-big-chill-1674630.html
Anyone know where the research is published?
Keep up th good work.
Correction…
This article in the UK Independent is interesting:
“Could the Sun play a greater role in recent climate change than has been believed? … No living scientist has seen it behave this way. There are no sunspots. ”
“Although at solar maxima there are more sunspots on the Sun’s surface, their dimming effect is more than offset by the appearance of bright patches on the Sun’s disc called faculae – Italian for “little torches”. Overall, during an 11-year solar cycle the Sun’s output changes by only 0.1 per cent, an amount considered by many to be too small a variation to change much on earth. But there is another way of looking it. While this 0.1 per cent variation is small as a percentage, in terms of absolute energy levels it is enormous, amounting to a highly significant 1.3 Watts of energy per square metre at the Earth. This means that during the solar cycle’s rising phase from solar minima to maxima, the Sun’s increasing brightness has the same climate-forcing effect as that from increasing atmospheric greenhouse gasses. There is recent research suggesting that solar variability can have a very strong regional climatic influence on Earth – in fact stronger than any man-made greenhouse effect across vast swathes of the Earth. And that could rewrite the rules. ”
Full article at:
http://www.independent.co.uk/news/science/the-missing-sunspots-is-this-the-big-chill-1674630.html
Anyone know where the research is published?
Keep up the good work.
DeNihilist (00:59:54) :
was just perusing your research paper site. Am I right in thinking that your presentation on Wolf, states that the Sun was not more active in the first half of the 20th century as compared to the last half?
The sun was less active in the first few cycles of the 20th century. The largest cycle4 [19] was at the middle [1950s]. My statement has really to do with comparing the 18th and 19th and the 20th.
tallbloke (02:30:27) :
Respect is a two way street. You can’t demand it, you earn it.
There is a difference between an attack on the ideas held by a person and an attack on the person. The former is fine, the latter is not.
I dont to want to show something that isnt my desire. I dont want harasse in any aspect Leif Svalgaard. On the contrary, I respect him a lot and I know he is one of the best authorities in the field.
For me, Svalgaard, be available to be questioned in that open space by laymen like me on that subject is an honour and a privilege. I want to mark my point. He knows better than much others that kind of things. What I would like is asking Why some things where, as I can say, rejected or neglectd in the past and We (all of us in general terms) took another way.
For example, Brian Tinsley et al, took their work in some direction that fits better what I understand as manifestations of energy, what Lorenz show us with his model of more restritecd equations.
As I understood, Courtillot was criticized because that jerks fenomena was only mathematics construtions. 😉 Thats why Leif was polite, in my opinion. 🙂
Please, dont be confused about my questions. My questions are more crude because something has been neglected: magnetic effects in “our models”. When to me, is very plausible that nitrogen and oxigen should be show us some effects of magnetic fields.
But, please, I dont want to atack anybody. Just learn and understand why we only took some way of thinking that was diverse about 30 ou 20 years ago.
In the last few days we have seen a microsunspeck as well as aborted ones… all in line and even at both poles… could that be it… the maximum of SC24?
Ray (08:22:34) :
In the last few days we have seen a microsunspeck as well as aborted ones… all in line and even at both poles… could that be it… the maximum of SC24?
No, Ray, that is too big a leap to take. There is but little doubt, however, that the sunspots are getting harder to see. Tomorrow I’m giving a talk on that at the AGU meeting in San Francisco: http://www.leif.org/research/AGU%20Fall%202009%20SH13C-03.pdf
PJMM (12:39:08) :
What I see is allways thinking in the energetic balance inside the system, when the debate is on. But even when we think in energetic balance we forgot to put in the discussion things that we got as settled. Like the air circulation, now the mantra of climate debates. Why is so cold in the poles and why that air is like traped there? Challenging the laws of thermodinamics? If we see the Earth as one body and his gases, why that differential in temperatures? Laws of thermodinamics don´t aplly in that fenomena? If applys, how?
Appears as though the excess heavier colder air, moving through the North Polar region, has kicked in the overflow release pump into the Northern hemisphere the last couple of years. Pump appears to working fine letting in plenty of cold air. Maybe be due to density changes in the near earth orbit, coupled with the lowered solar output. . . .
“Maybe be due to density changes in the near earth orbit, coupled with the lowered solar output. . . .”
Maybe. But the only process that is very knew because the sun flares is the one that was discovered by Wilcox et al, who mr. Leif was part of the team.
But my question is more crude than mere air circulation. I Would like to know why we have an big differential in temperatures between the poles and the equator. I mean, ok, we got the earth obliquity but why that cold looks traped in the poles. And why we dont have more heat/cold (energy) transfer between the poles and the equator? As one “normal” body? What causes that differential in temperatures? Is the energy of sun enouph to explain the amount of energy differential? Or we have something traping the cold air there, near the poles? Maybe I dont have physics formation to understand. 😉 But looks to me that the difference should be lower than it is.
But thanks, Carla.
I dont want to invent nothing or trying to make a big discovery. Only I ask questions that are the basics to understand the process later.
“Maybe be due to density changes in the near earth orbit, coupled with the lowered solar output. . . .”
My apologyses, in fact some explanation exists (Shindell; Luterbacher) and was modeled.
Thanks a lot. It was a good information.
Leif Svalgaard (05:55:49) :
tallbloke (02:30:27) :
Respect is a two way street. You can’t demand it, you earn it.
There is a difference between an attack on the ideas held by a person and an attack on the person. The former is fine, the latter is not.
I agree.
I don’t like falling out with you. I have huge respect for your scientific knowledge and accomplishments. For the record, my comment had nothing to do with any fraudulent behaviour. It was aimed at the tendency to ridicule and denigrate the person as a way of dismissing them. I have had this from a lot of the warmist scaremongers too.
I don’t cling to any particular theories, but I have found what I believe to be interesting correlations which I think are worth further investigation. I don’t have any problem with the fact that you don’t, but if you make an accusation that I am “spouting” some sort of “pseudo science” that comes across to me as a personal attack, rather than a critique of my work on these phenomena.
Anthony expressed a wish that we should not discuss ‘barycentric’ ideas on here. It’s his blog and I try to respect his wishes. I had suggested to Paul that we move our discussion elsewhere before you came along and hit me with both barrels. That’s why I reacted, and I apologise for any upset or misunderstanding I caused.
On a scientific note, I’d like to find out if any work has been done on quantifying the amount of heating induced in ferromagnetic matter when it is brought into a magnetic field.
PJMM (12:58:24) :
The Poles have little or no sunlight during the peak of their respective winters due to the tilt of the Earth, so they don’t get enough light from the sun to warm significantly during their respective summers. At certain times of the year, each pole has a vortex of circulating air which tends to trap very cold air inside it. The sea at the South Pole also forms a circular current which keeps cold water in; land masses at the North Pole stop an effective polar current forming there.
Supposition: The polar vortices are driven by an electromagnetic mechanism. When the magnetic fields of the Sun/Earth system connect, charged plasma from the solar wind enters the atmosphere. The charged plasma disturbs the Northern polar vortex allowing cold air to spill out. This changes NH weather patterns. If the period of disturbance continues over a number of years climate change ensues.
Just thinking?
PJMM (11:58:28)
I dont want to invent nothing or trying to make a big discovery. Only I ask questions that are the basics to understand the process later.
Good questions PJMM, diagnostic attitude. Your thought waves resonate and cross over many of the same questions and areas I study. heh
Did you ask yourself why all ‘planets’ polar areas are ….