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.
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Does anyone know what magnetism is? In terms of fundamental particles and their motions?
Keith (16:43:01) :
“[Fitzy – you suspect that the earth is tethered electromagnetically to the sun]?”
http://www.spacedaily.com/reports/Giant_Electrical_Tornadoes_In_Space_Drive_The_Northern_Lights_999.html
Thanks for the link, Keith. This could explain what happened when a display of strange lights was seen over Norway on Wednesday 9th December, 2009.
The strange event over Tandberg was witnessed by many people. It began when a white light rose from behind a distant mountain, paused and then started to rotate making a spiral in the sky and filled it In a few seconds. Following this, a greenish blue light emerged out from the middle of the spiral and was visible for around 10 minutes or so before disappearing.
Links:
http://www.earthfiles.com/news.php?ID=1650&category=Environment
http://www.nrk.no/nyheter/distrikt/nordland/1.6902336
Interesting bit on solar turbulence:
http://esciencenews.com/articles/2009/12/11/weir.space.and.dimmed.sun.creates.200.million.mile.long.lab.bench.turbulence.research
Normally the ‘noise’ from violent eruptions on the sun would disturb the turbulent flow. Ulysses’ controllers had cleverly contrived for the spacecraft to pass over each of the Sun’s poles during two different solar minima making it possible not only to gather data but also to be able to compare two different energy levels in a turbulent flow. The level of turbulence is down by a factor of 2 in the most recent solar minimum compared with the previous one.
BBC meteorologist Paul Hudson (who CRU and their cronies criticised in the emails) has a blog post up today about the quiet Sun and a possible Dalton repeat. He’s written about Svensmark and the lack of warming before (the latter was why he was mentioned in the emails).
http://www.bbc.co.uk/blogs/paulhudson/
I got to thinking (something I typically try to avoid): Could the solar cycle cause changes in the spectrum of solar irradiance? If so would this have an effect on the chemicals that make up the oceans and atmosphere–water and nitrogen? Wiki says water absorbs UV and near IR; Nitrogen absorbs sunlight in the EUV wavelengths. Sunlight has a low UV component, although it increases owing to magnetic fluctuation associated with sunspots. So, sunspots cause UV, which causes water and nitrogen to absorb energy and heat up. Remove the sunspots: Water and nitrogen don’t heat as much.
Or should I return to an avoidance of thinking?
Sunspot numbers for the last 400 years per Wikipedia:
http://en.wikipedia.org/wiki/File:Sunspot_Numbers.png
The pioneers in solar observation & measurement beginning in the 1840’s used apparatus cabable of recording magnetic energy this added important information to sunspot counts.
Earlier than the 1840’s, data was more limited. Observation & measurement of the Sun’s behavior during the Dalton Minimum was not as precise and during the more severe and protracted Maunder Minimum the data is sparser still.
And yet even more patchy during the Medieval Warm Period.
The exclusion of solar variability effecting global temperature is not “settled” Science.
There is more to understand.
And some things in the past, present and future we may never know with certainty.
TFN Johnson (08:58:32) :
I’m confused about the number of sunspots. This article says 1 (image at top of article.
The widget has “#13 sunspots”. I sthat 13 or a reference to spot 13?
The sunspot ‘number’ is S = 10*number of groups + number of spots.
With three spots in one group [which is about what we have now], we would calculate S=10*1+3=13
tallbloke (09:53:53) :
Does anyone know what magnetism is? In terms of fundamental particles and their motions?
Magnetism is a relativistic effect that is needed to make electrical phenomena look the same in all reference frames. You can find lots of information on that [also some disagreeing] by googling ‘magnetism relativistic effect’
tallbloke (09:53:53) :
Does anyone know what magnetism is? In terms of fundamental particles and their motions?
At some level our ordinary language fails us in explaining things that are truly ‘fundamental’. Assume you had asked ‘why do two electrons repel each other’? The standard answer is that like charges repel, but that is not really telling you much. To get a bit closer, one introduces the concept of virtual photons. Electrons emit and absorb virtual photons all the time. Let us look at an electron emitting a [virtual] photon. As a photon has momentum and since momentum is conserved [why? because space is isotropic… – getting really deep here] the electron will recoil in the opposite direction of the emitted photon. If the photon meets another electron it will give that electron a kick in the direction of its travel, which is opposite to the recoil of the emitting electron, hence it looks like the two electrons are repelling each other. You can keep drilling down: what are virtual photons anyway and why does isotropy of space mean that momentum is conserved? At some point our ‘knowledge’ and ability to question will bottom out, and it is ‘turtles all the way down’.
The Earth is a halfdome resting on the back of large elephant standing on an enormous turtle…
Ipse Dixit (11:33:53) :
Could the solar cycle cause changes in the spectrum of solar irradiance?
It can and it does. It seems that UV and infrared change in opposite directions even if TSI is constant. These changes are not large, though.
Ipse Dixit (11:33:53) :
There is something to be said about a shift in Solar Spectrum.
I believe it has done just that, as TSI is constrained to a very narrow range.
The atmosphere is generally opaque to the lower ranges of UV, so a drop in visible but an increase in UV would lead to a change in how Solar Energy interacts with the atmosphere and surface.
This would make for a much better topic that kicking the TSI bucket around.
Leif Svalgaard
(12:07:56)
” At some point our ‘knowledge’ and ability to question will bottom out, and it is ‘turtles all the way down’.”
I like that because it agrees with my long held opinion that our interpretation of reality is limited by the constraints of logic and logic in itself is insufficient to explain reality.
In fact logic itself is simply an extension of our ability to sense that there is a difference between self and not self.
Having made that distinction all knowledge is just a step by step accrual af additional logical steps and the number of steps taken is a measure of intelligence but not necessarily a true reflection of any independent reality.
I’ll go and lie down now 🙂
tallbloke (09:53:53): Does anyone know what magnetism is? In terms of fundamental particles and their motions?
To understand electricity and magnetism I would recommend “Introduction to Electrodynamics” by David Griffiths;
http://www.amazon.com/Introduction-Electrodynamics-3rd-David-Griffiths/dp/013805326X
David explains in terms of useful analogies the beauty of Maxwell’s equations.
M Simon (11:15:22)
Thank you for that link. It supports my observation that the degree of turbulence in the flow of energy from the sun dictates the rate of energy loss from upper atmosphere to space independently of any variation in the power of the solar energy flow.
We now need to regard a period of more active sun as a time of increased energy LOSS at least from the top of the stratosphere upwards and possibly from the surface as well subject only to a moderating effect from variations in the rate of oceanic energy loss to the troposphere.
The opposite of what we thought but answers a lot of questions as I explained above.
If we are headed into to a little Ice Age how fast does the Global temperature drop?
From Eichler et al GRL 36 (2009) it appears from my mark one eyeball to take 50 years. I assume on a geologic scale that is very fast but on a human scale that’s when my grand kids get to 50. No grand kids yet but soon.
Thanks Leif for posting here. I’ve see you’re posts and work and you are simply amazing.
“”” Roy Spencer (10:19:43) :
sounds like a cool experiment, Jeff. But how do you know they are not pixie contrails? “””
Well it maybe a cool experiment Dr Roy, but not too realistic; the ethanol after all is for drinking, not for making clouds.
Since ethanol is not considered a common type of cloud formation in the earth atmosphere; better to stick with water clouds. Formation of water droplets is a function of the physical properties of the H2O molecule; including that 104 degree angle built into the molecule; which makes it a highly polar molecule.
Anyone who’s ever taken a hot shower knows that water droplets for readily on cold surfaces. The problem is how do you get a water droplet to form when there is no cold surface, as in the upper atmosphere. It is not commonly observed that water drops suddenly appear out of vapor at tennis ball size. Common sense says they ought to start small, as a few molecules meet up and coagulate. Maybe it takes at least two water molecules to start a droplet, and more are subsequently added. At some point we can say we clearly have an identifiable drop of water; roughly spherical having a finite radius (r), and even a recognizeable surface.
So now we have surface tension to contend with; and as all Physicists know; a consequence of surface tension is that water droplets do not at all like being small. The internal pressure inside a drop of water exceeds the ambient pressure outside; and an 8th grade high school exercise using the principle of virtual work demonstrates that the excess internal pressure in a water droplet, is 2T/r, where T is the surface tension in Newtons per metre, and r is the radius in metres.
Now you can see whay water droplets don’t like being small; that internal excess pressure goes sky high as the radius diminishes.
So water likes to have a substrate to form droplets on, so they can start at non zero radius. Any bacterium or volcanic dust particle, can serve as a starting substrate for water vapor to form liquid droplets; and that is where the cosmetic rays come in; by creating charged particle tracks in the atmosphere that droplets can grow on, at finite radius.
Water quite readily forms supersaturated vapor in clean air environments; and doesn’t condense easily absent a substrate. That is why you should never nuke a cup of clean water to make coffee. It can overheat above the boiling point without steam forming bubbles in it; but if you are holding your face over it, when the CRs clobber into it, and it explosively turns to steam; you are in a world of hurt.
Just because you have never met a cosmetic ray face to face, is no reason to malign them; they can be your frieds; if you are a cloud physicist (or chemist).
And don’t forget to put the coffee in the water before you nuke it.
Leif Svalgaard (12:14:23) :
Can you quantify those changes, or has someone already done this?
By opposite directions, do you mean that as Solar Activity drops, Solar Irradiance changes to an increase in UV and IR, and as Solar Activity rises Solar Irradience changes to decrease in UV and IR?
rbateman:
Less UV at minimum I believe:
“A 12-year low in solar “irradiance”: Careful measurements by several NASA spacecraft show that the sun’s brightness has dropped by 0.02% at visible wavelengths and 6% at extreme UV wavelengths since the solar minimum of 1996.” from
http://science.nasa.gov/headlines/y2009/01apr_deepsolarminimum.htm
George E. Smith (14:06:49) :
“Just because you have never met a cosmetic ray face to face, is no reason to malign them; they can be your friends; if you are a cloud physicist (or chemist).”
I believe that GCR affect climate, but not in the way Svensmark suggests. The albedo effect is immediate and minimal. However, there may be a possibility of a tertiary effect, with a variable delay of up to several decades. Period of solar minimum is far too short (acting as narrow band pass filter) to produce an observable and convincing correlation. Sequence of several cycles of low solar activity is required for 3-4 distinct sequential steps to take place in order to produce a significant cooling effect by increased intensity of GCR.
rbateman (14:25:54) :
Can you quantify those changes, or has someone already done this?
By opposite directions, do you mean that as Solar Activity drops, Solar Irradiance changes to an increase in UV and IR, and as Solar Activity rises Solar Irradience changes to decrease in UV and IR?
Juan Fontenla:
http://www.lowell.edu/workshops/SolarAnalogsII/abs.php?a=fontenla_t&t=t
You can google this to find more.
Don’t know if this is cricket, if not then please delete.
Picked this comment off of http://www.scepticalscience.com, was just wondering if Dr. Spencer could comment on it .
{quote} Robert Ellison at 11:05 AM on 12 December, 2009
Amongst the Major Unknowns in Climate are the following
Solar
Phenomenological reconstructions of the solar signature in the Northern Hemisphere surface temperature records since 1600
N. Scafetta and B. J. West
JGR Received 18 January 2007; revised 4 May 2007; accepted 5 June 2007; published 3 November 2007.
[1] A phenomenological thermodynamic model is adopted to estimate the relative contribution of the solar-induced versus anthropogenic-added climate forcing during the industrial era. We compare different preindustrial temperature and solar data reconstruction scenarios since 1610. We argue that a realistic climate scenario is the one described by a large preindustrial secular variability (as the one shown by the paleoclimate temperature reconstruction by Moberg et al. (2005) with the total solar irradiance experiencing low secular variability (as the one shown by Wang et al. (2005)).
Under this scenario the Sun might have contributed up to approximately 50% (or more if ACRIM total solar irradiance satellite composite (Willson and Mordvinov, 2003) is implemented) of the observed global warming since 1900.
Clouds
“The new method is a conceptual breakthrough in how we analyze data,” said Anthony Del Genio, a scientist at GISS and co-author of the companion paper.
“What it shows is remarkable,” said Wielicki (Dr. Bruce Wielicki of NASA Langley Research Center, Hampton, Va.) “The rising and descending motions of air that cover the entire tropics, known as the Hadley and Walker circulation cells, appear to increase in strength from the 1980s to the 1990s. This suggests that the tropical heat engine increased its speed.
The faster circulation dried out the water vapor that is needed for cloud formation in the upper regions of the lower atmosphere over the most northern and southern tropical areas. Less cloudiness formed allowing more sunlight to enter and more heat to leave the tropics.”
“It’s as if the heat engine in the tropics has become less efficient using more fuel in the 90s than in the 80s,” said Wielicki. “We tracked the changes to a decrease in tropical cloudiness that allowed more sunlight to reach the Earth’s surface. But what we want to know is why the clouds would change.”
The results also indicate the tropics are much more variable and dynamic than previously thought.
“It suggests that current climate models may, in fact, be more uncertain than we had thought,” Wielicki added. “Climate change might be either larger or smaller than the current range of predictions.”
The observations capture changes in the radiation budget-the balance between Earth’s incoming and outgoing energy-that controls the planet’s temperature and climate.
The previously unknown changes in the radiation budget are two to four times larger than scientists had believed possible. The reason why and the degree to which it changed are surprising scientists and create a powerful new test for climate models.
“The question is, if this fluctuation is due to global climate change or to natural variability,” said Del Genio. “We think this is a natural fluctuation, but there is no way to tell yet.”
Complexity
Climate shifts occurred 4 times in the last 100 years around 1910, the mid 1940’s, the mid 1970’s and 1998/2001 (Tsonis et al, 2007, Swanson et al 2009). The lack of global warming since 1998 is consistent with the climate behaving as a forced nonlinear oscillator. Small changes in forcings (solar, gases and aerosols, albedo) are alternately amplified and damped (nonlinear) by global climate processes and climate then oscillates for a time around a different climate mean.
The direct impact of greenhouse gas increase since the start of industrialisation is about 0.5 degrees centigrade of global temperature increase theoretically. It is not insignificant as energy in the climate system. The total effect is unknown because it feeds into a dynamic climate system of sun, orbit, ocean, atmosphere, ice, clouds, gases and aerosols operating interactively. All of these change all the time. The exponential growth of ice cover is implicated as factor in ice ages – extreme nonlinear climate events. Global cloud cover has been known to change from ISCCP data collected from 1984 and the argument has been about cause and effect. There is a little more cloud cover since about 1999 – which came first the clouds or the current cooling? The question is meaningless as climate is dynamic and complex. Small changes in initial conditions lead to climate fluctuation which then settles into a different mean climate state.
Tsonis, A. A., K. Swanson, and S. Kravtsov (2007), A new dynamical mechanism for major climate shifts, Geophys. Res. Lett., 34, L13705, doi:10.1029/2007GL030288.
Swanson, K. L., and A. A. Tsonis (2009), Has the climate recently shifted?, Geophys. Res. Lett., 36, L06711, doi:10.1029/2008GL037022.
At the policy level – it is a matter of social, economic and environmental risk. Continued global economic growth is critical for billions of people now and increasing greenhouse gases increases forced system instability – a balance of risk is required. {end quote}
The continued lack of warming in the atmosphere and muted warming or cooling (depending on which researcher) of the ocean and atmosphere suggests that there is less urgency and that alternative development strategies proposed by Bjorn Lomberg amongst others can provide a better and less economically risky (to billions in the developing world) solution. A few decades is all that is required to develop dozens of low cost options for energy and development – a real market solution as opposed to the ‘ecosocialist’ aspirations of one website I have recently visited
meemoe_uk (02:25:30) “Average cloud lifetime […] main effect […] on climate is the variation in location of cloud cover, which shifts to the oceans. This warms the oceans slightly, while the land becomes colder and more arid.”
Some interesting ideas (but I do not advocate limiting focus to GCRs).
PJMM (02:54:21) “So, nothing of this is new as we thougth. The answer maybe is more “simple” than we think.”
Agree.
I strongly encourage everyone to read the Russian literature. If more contributors read Barkin, Sidorenkov, & Klyashtorin, these discussions might get further. Within a few days of reading dozens of Barkin papers (not just a few), I had
these rough results drafted.
Piecing together clues scattered by Barkin eliminates reliance on “mysterious forces”.
Related:
tallbloke raises some important/enlightened points, but tallbloke: Have you read Barkin yet? (I suspect not, judging by your comments about the core, subcrustal fluids, etc.)
Thanks for the link to your blog. I encourage you to be clear & explicit that you are smoothing SSBz at a Jupiter subharmonic; the confounding amongst the various indices of solar system dynamics is thick (this cannot be underscored enough) and you may cause other (less enlightened, perhaps) researchers to waste precious time figuring out that SSBz might not be where the money is (as I will acknowledge you have hinted (without being explicit) by smoothing at a Jupiter subharmonic). Cheers.
Patrick M (06:33:42) “May I suggest a special blog? The “RealClimateCensored blog””
Good idea – as long as people don’t abuse it with goofy drivel aimed at hyperpartisan humor rather than science — I suppose there would have to be some censoring of “RC Censored” to make sure it did not play into the hands of alarmists, via strings upon strings of “nutjob denier” evidence that “all nonalarmists are nutjob deniers” etc., much of which would undoubtedly be planted by extreme-alarmists posing as “nutjob deniers”.
Paul Vaughan (17:13:38) :
tallbloke raises some important/enlightened points, but tallbloke: Have you read Barkin yet? (I suspect not, judging by your comments about the core, subcrustal fluids, etc.)
Thanks for the link to your blog. I encourage you to be clear & explicit that you are smoothing SSBz at a Jupiter subharmonic; the confounding amongst the various indices of solar system dynamics is thick (this cannot be underscored enough) and you may cause other (less enlightened, perhaps) researchers to waste precious time figuring out that SSBz might not be where the money is (as I will acknowledge you have hinted (without being explicit) by smoothing at a Jupiter subharmonic). Cheers.
Hi Paul, a good point, but you get a similar result even if you pick a smoothing period which is ‘out of phase’ both with Jupiter’s orbital period and the Jupiter/Saturn synodic period. Try 21 years. In any case, since Jupiter is by far the biggest planet, equal in effect on SSB motion to the other three gas giants, it will dominate whichever time period you pick won’t it?
Thanks for visiting my new blog, I really hope you call back and contribute, though I appreciate there are more blogs than time permits.
To Lief Svalgaard
Thanx, I’ve noted your formula.
Re: tallbloke (02:34:22)
I applaud your synthesis & pioneering research.
I will clarify: I am not criticizing your time-integration bandwidth. Rather I am drawing attention to the confounding – as I said, it is thick – so thick that this cannot be underscored enough. I am suggesting that we keep in mind that there may be lurking variables that are (at least partially) confounded with the variables we study. This is not a trivial consideration. In fact, I would say that opponents have capitalized on a lack of awareness of this.