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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Looking at the scatter-plot, I basically see a cloud (pardon the pun) with some interesting observations causing the line to have a slightly non-zero slope.
Even if the slope coefficient were statistically significant, the plot basically indicates no relationship between the Geo-Ap Index and cloud cover.
I would like to know what time periods had Geo-Ap Index values between 20 – 25.
I also am waiting to see what comes of CERN’s Cloud experiment. Here is an hour long presentation by Dr. Jaspar Kirkby about what the hypothesis is and how they are going to test it. If you haven’t watched it, you are missing out.
http://cdsweb.cern.ch/record/1181073/
P Wilson –
I’m not sure how rain affects the climate, but I’m sure it does. But Svensmark’s work concerns the reflectivity of mid-level clouds.
But rather than getting it second hand from me, it’s best to read about it from the scientists themselves. Dave L gave a good link to the CERN site. I think that’s where you’ll find the theory best distilled. Plus it’s in video form.
Don’t know if this link has been already been posted but I found it interesting:
http://seekingalpha.com/article/175641-climategate-revolt-of-the-physicists
It presents a lecture by Jasper Kirkby on recent research being done by physicists.
See “Henrik Svensmark on Global Warming”:
The term “cosmic rays” is misleading in the sense that cosmic rays consist primarily of relativistic protons (and small amounts of heavier nuclei) which collide with atoms in the atmosphere producing pions which immediately decay to muons.
It’s the muons (fat electrons) which survive to roughly 6000 meters and decay into an election and two fat neutrinos and amplify the natural cloud formation process.
In particular, it looks at cloud formation in the open oceans.
And the CLOUD experiment at CERN is expected to go online with the a full beam in 2010:
http://public.web.cern.ch/public/en/Research/CLOUD-en.html
“The implication being that the stratosphere and upper levels of the atmosphere lose energy faster to space when the solar wind is more turbulent.”
Imagine a balloon. It has a given surface area. Now warm the air inside the balloon. The balloon will expand. This expansion increases the surface area allowing it to radiate more heat away.
Dr. Spencer;
About a month ago, in the comments for one of your posts here, I posted a question for you regarding a rather obscure paper I had come across, which seemed to me to suggest some rather startling insights on the contribution of CO2 to the “greenhouse effect”. Since I posted in the wee small hours, you probably missed it, so I’ll try again when the sun is still shining and see if I have better luck. To save time I’ll just do a C&P
Dr. Spencer;
Or anyone else here who can help me with a question that’s been nagging me for a couple days. The other day, in the comments for the first post about Monckton’s appearance on Glenn Beck’s show, I got into a tete a tete with another commenter about a study that utilized spectral analysis to separate the contributions of the various GHGs to the greenhouse effect. In googling about on the topic I came across another paper which covered the same ground from a slightly different perspective
http://ams.confex.com/ams/Annual2006/techprogram/paper_100737.htm
Evans and Puckrin 2006 Measurements of the Radiative Surface Forcing of Climate
The link is to the abstract, you need to click the Extended Abstract link to access the pdf of the whole paper.
The experiment in the paper utilized the spectral analysis technique to measure the downward LW radiative flux to the surface of the various GHGs. Since the paper is couched in the usual AGW blather, my first inclination was to doubt its qualities and indeed as a work of science I didn’t find much to recommend it. But, though their conclusions seemed fairly illogical, their experimental techniques seemed reasonable and the data in the their tables is what has had me ruminating. Particularly their Tables 3a and 3b which list respectively their seasonal observations for winter and summer. The readings for the cold dry air of winter show downward LW flux to the surface from CO2 at 30-35W/m2 and from H2O at 95-125W/m2 in line with the approx. 25% contribution of CO2 to the greenhouse effect. What’s shown in the summer readings is what has had me thinking. The H2O numbers went up to 178-256W/m2 in the warm humid air of summer, but the CO2 numbers went down, not just in relative terms but in absolute terms to 10.5W/m2, a third of the winter rate, and bringing the contribution of CO2 to the total GE to 3-4%, a much smaller value than I’ve usually seen quoted. this phenomenon was so obvious that even the clearly warmist authors commented on the higher H2O flux suppressing the flux from the other GHGs. Since this study was done in Canada and most heating of the planet occurs in the Tropic and Subtropic latitudes, which are presumably warmer and more humid than even the summer in Canada and would probably have even higher levels of H2O flux, if this phenomenon is real and consistent it would seem to me to indicate that the contribution of CO2 at those latitudes would be an even smaller percent.
Since downwelling LW is pretty much the heart and soul of the supposed “greenhouse effect”, it seems to me that if this experimental technique is valid and if it could be broadly applied, especially in the 40N to 40S latitudes, we would have a fairly definitive measure of the contributions of the various atmospheric components to global warming. Also, since most estimates of DLW in tropic and subtropic latitudes are at least 100W/m2 higher than those measured by the Canadians, if the suppressive effect of H2O was demonstrated to be real, it would make Plimer’s much maligned assertion that H2O accounts for 98% of the greenhouse effect look quite reasonable.
I guess, after all that, my question is am I interpreting this correctly, or like some dedicated alarmist, making wild leaps beyond the evidence?
Errata – I meant 6000 feet not 6000 meters.
Dr. Spencer
Your detrended AP index has a break in the line at the same point as where the downturn in the index occurs in your longer untrended AP index version. You have also adjusted “up the values from around 5 to around 10. Could you comment on why this was done?
I came across a 2008 USGS paper by Jeff Love :
http://geomag.usgs.gov/downloads/pt2008.pdf
In this paper it discussed in great detail the Haloween magnetic storm from Oct 28 to 31 of 2003. Again comparing your 5-month deternding to what appears to be a 2 day event, do you feel that the intesnsity of that short storm is reflected in your graph? Could you look through the more detailed record just after that storm in your cloud records to get a better idea of a causal relationship? My guess it would be short lived.
They also talk about the magnetic storm in 1989. I was doing a geophysical survey in the high arctic at the time. It completely messed with my proton-procession magnetometer for over 2 weeks. I remember some very spectacular borealis nights that summer.
Thank you for your work.
Welcome to the club! The theory of low-level cloud cover being the primary short-term temperature control mechanism of planet earth is very old. The theory that sunspot activity modulates cosmic radiation striking the earth and that cosmic radiation seeds low-level clouds is also relatively old. The fact that volcanic activity does the same thing is also known and even the AGW crowd does not dispute the volcanic connection.
The boys and girls at CERN are very excited to think they may be well on their way to proving the cosmic-ray-cloud-seeding theory. My personal opinion is that if the sun continues its current funk, everyone had better get out their woolies. The AP index seems to be mimicking it’s behavior at the onset of The Little Ice Age when temperatures dropped very rapidly according to archeological evidence.
CH
The theory of Solar evolution like climate science has overlooked many
uncomfortable, theory busting anomalies, resulting in a less than stellar performance when explaining space weather. Both its causes and effects, and its influences on the Earth, and our climate.
Plasma science has long established a pattern of connection between the solar environment, and the behaviour of Earths Magnetosphere, Birkeland’s terrella experiments (around 1895) demonstrated an electromagnetic connection between the Sun and the Earth.
While NASA talks of ‘Solar Winds’, a mechanical misnomer, plasma science would describe Earth immersed in a charged particle soup, and when charged particles travel in a similar direction, we get magnetic effects, where there is magnetism there is electricity.
The Earth is probably a charged body in space, a leaky capacitor if you will, receiving and discharging electrical energy from the sun, both back into space and between the upper atmosphere and the rocky Earth itself.
That particle soup, or PLASMA, acts as a conduit for electrical energy, not quite a perfect conductor, but very efficient never the less.
The visible spectrum, IR and Ultraviolet do not tell the entire story of weather and climate. When Plasma science
The Earth is probably not isolated in an empty vacuum, more research needs to be none, but I’m hedging my bets on the Earth being tethered to the Sun electromagnetically.
Research PLASMA COSMOLOGY and the ELECTRIC UNIVERSE THEORY, another field damaged by orthodox, CRU style peer review.
Perception is 9/10 of reality. That’s how they tried to brainwash everyone into believing AGW with the corporate media they own. Repeating the same thing over and over again for decades has almost done the Trick.
This is why we need to propagate our perceptions which in fact are reality, but the masses don’t know they are reality. The masses just need to have something to consume. This is why we must promote the Solar Minimum till it hurts and we’re blue in the face talking about it. This is why we must show winter scene pictures and winter scene videos always to our advantage. Show the blizzards across North America and Europe as much as possible.
The middle class are the thinking class, which is why it is constantly being widdled away. Best way to do that NAFTA and CAFTA. Make it impossible for the middle class to gain any ground. Going back to bilateral trade agreements may save the USA and our culture if we act in time.
http://wethefree.blogspot.com/2009/12/it-has-begun.html
Thanks Jan. The cloud experiment has already begun.
This may be OT but, then again, it may not be. Whatever, it’s super interesting. Weather patterns (literally) on Saturn:
http://www.sphere.com/science/article/cassini-spacecraft-images-show-mysterious-hexagon-on-saturn/19273284
Quick thank you to Dr Svalgaard & magicjava for the reading suggestions. That’s the xmas break covered 🙂 I keep thinking a ‘peer recommened’ reading list would make a useful addition to this site, maybe via Amazon’s api.
The plasma physics one would have been next on the list as it’s one of the things that sparked my curiosity after leasing some satellite capacity and discovering the ‘cosmic backhoe’ effect.
Svensmark’s 2009 papers provide interesting clues:
Cosmic ray decreases affect atmospheric aerosols and clouds H Svensmark, T Bondo, J Svensmark – Geophysical Research Letters, 2009
Model of optical response of marine aerosols to Forbush decreasesMB Enghoff, H Svensmark, Atmos. Chem. Phys. Discuss., 9, 22833–22863, 2009
I would like to reinforce what Anthony said about this being a rough correlation.
Keep in mind that these plots are looking at the gross change in reflectance.
Different parts of the earth have different reflectance (sea, rainforest, plains, deserts, mountains, and snow/ice cover to hit the high spots) some of these (ice, deciduous forest, e.g.) vary seasonally. When clouds cover an area you first subtract the shadowed part (or part of it) from the net reflectance and then add the reflectance of the clouds. Further, Svensmark theorizes that the clouds are not formed uniformly but vary with latitude and terrain. So the location and timing of the clouds is obviously quite important.
Anyone who expects a simple relationship just does not understand what is, or may be, going on. Considering the number of variables any correlation of reflectance with any one is worthy of attention.
See latest:
Status of the CLOUD experiment – November 2009 04:26 min. / 11 November 2009 / CERN
Expecting data next year.
Looking at my post of 12:33:51, obviously I failed to mention how a change in cosmic rays, or the Ap proxy, might interact with the ENSO, or Atlantic or Pacific Decadal Oscillations. Lord knows what else that we don’t even know about (“unknown unknowns”).
It is just not reasonable to expect a simple correlation.
My Christmas present this year is Climategate. I don’t need or want anything else. I want to give as a present a DVD titled “ClimateGate: Everything They Didn’t Want You to Know” to everyone I know. When the ask, who are they? I’ll say, watch the movie.
I need you to help me with this. Can we put together a Climategate video we can burn to DVD from a torrent file of the information we have so far? The movie can always be revised in the future. Lots of snow blizzard scenes and stuff about the Solar Minimum in it. I need your feedback on this. Please address this comment directly with your feedback. Can we do this?
Thank You
MJN
“…Note that there is some similarity between the two plots….” -RS
Some, yes, but not huge. I’m a bit surprised at the correlation factor of 0.57. The linear fit seems to be heavily influenced by the tail of the dog at lower right of the scatter diagram, where the Flux Anomaly is between -0.4 and -0.6 w/m², at high Ap indices. These correspond to a very brief interval, roughly Mar — Dec of 2003, a period of abnormally high Ap values (>20). This is very short to hang your hat on.
I note, belatedly, that the ordinate labels differ between the Flux diagram and the scatter diagram. Has some step or information been omitted?
If not, then the tail of the dog seems problematic. There seem to be too many data points in the tail, given how few times the Flux drops below -0.4. Where in time, for example, is the point (-0.64, 23)?
” Leif Svalgaard (10:20:50) :
If the mechanism is supposed to be via cosmic rays, the relevant correlations should be between cloud cover and the cosmic ray intensity”
During the 50’s and early 60’s the US was doing air burst H-bomb tests. These would put out a LOT of gamma/X-ray’s. The USAF measured the atmosphere, before and after, the big firework. My guess is that much of this has now been declassified.
You could look back at this data and see if they found cloud formation afterward….
Stephen Wilde (11:45:42) :
I’m still being mentally exercised by this finding:
That was just the usual NASA hype. The ‘breathing’ of the ionosphere has been known by decades and has nothing to do with the climate.
Also the monsoon and seasonal variations in oceanic zooplankton & chlorophyll.
Rats!!
AMONGST THE MANY VARIABLES…etc…
If I think of any more worth mentioning, Fang and I will make another entry.
/Spanish Inquisition Sketch
My work is very sensitive to the amount of bulge in the atmosphere at high altitudes due to solar activity. I know the bulge can affect atmospheric densities substantially at high altitude.
I am not asserting anything because it is not my area of expertise, but isn’t it possible that the variation in pressure could have a substantial impact on cloud formation in the stratosphere? In my naive view, the bulge could decrease pressure in the upper stratosphere, and when I get low pressure on my barometer here on Earth, I am likely to see clouds. Stratospheric clouds, from what I understand of the debate, tend to allow sunlight to pass through, but reflect radiation back down to the Earth, increasing warming. A lessening of the bulge would then presumably increase pressure, diminishing high atmospheric cloud cover, allowing more radiation to escape.
I’m sure if this is dumb, I’m going to get pummeled, but I still would like to understand things better so, have at it.