As many regular readers know, I’ve pointed out several times the incident of the abrupt and sustained lowering of the Ap Index which occurred in October 2005. The abrupt step change seemed (to me) to be out of place with the data, and the fact that the sun seems so have reestablished at a lower plateau of the Ap index after that event and has not recovered is an anomaly worth investigating.
From the data provided by NOAA’s Space Weather Prediction Center (SWPC) you can see just how little Ap magnetic activity there has been since. Here’s a graph from October 2008 showing the step in october 2005:
click for a larger image
However, some have suggested that this event doesn’t merit attention, and that it is not particularly unusual. I beg to differ. Here’s why.
In mid December I started working with Paul Stanko, who has an active interest in the solar data and saw what I saw in the Ap Index. He did some research and found Ap data that goes back further, all the way to 1932. His source for the data is the SPIDR (Space Physics Interactive Data Resource) which is a division of NOAA’s National Geophysical Data Center (NGDC). He did some data import and put it all into a mult-page Excel spreadsheet which you can access here.
I had planned to do more study of it, but you know how holidays are, lot’s of things to do with that free time. I didn’t get back to looking at it until today, especially after SWPC updated their solar datasets on January 3rd, including the Ap Index. Looking at the data to 1932, it was clear to me that what we are seeing today for levels doesn’t exist in the record.
About the same time, I got an email from David Archibald, showing his graph of the Ap Index, graphed back to 1932. Having two independent sources of confirmation, I’ve decided to post this then. The solar average geomagnetic planetary index, Ap is at its lowest level in 75 years, for the entirety of the record:
Click for a larger image – I’ve added some annotation to the graph provided by Archibald to point out areas of interest and to clarify some aspects of it for the novice reader.
The last time the Ap index was this low was 1933. The December 2008 Ap value of 2, released by SWPC yesterday, has never been this low. (Note: Leif Svalgaard contends this value is erroneous, and that 4.2 is the correct value – either way, it is still lower than 1933) Further, the trend from October 2005 continues to decline after being on a fairly level plateau for two years. It has started a decline again in the last year.
This Ap index is a proxy that tells us that the sun is now quite inactive, and the other indices of sunspot index and 10.7 radio flux also confirm this. The sun is in a full blown funk, and your guess is as good as mine as to when it might pull out of it. So far, predictions by NOAA’s SWPC and NASA’s Hathway have not been near the reality that is being measured.
The starting gate for solar cycle 24 opened ayear ago today, when I announced the first ever cycle 24 sunspot. However in the year since, it has become increasingly clear that the horse hasn’t left the gate, and may very well be lame.
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Leif Svalgaard
I agree that numerology can be fun and interesting and mostly harmless
Ignoring the ‘numerology’ jibe, harmonic theory is also pretty useful. Tomes used it to predict the existence of a sub atomic particle at around 37.5Mev two years before it was discovered. And found it fitted with the discovery of periodic ‘walls’ of galaxies in space at around 72Km/sec which weren’t explicable using big bang cosmology, among many other ‘numerical coincidences’. The ‘narrowness’ of the confine of reality mostly depends on how your blinkers are adjusted. 😉
the surface rotation predicts an oblate ellipsoid with an equator-pole radius difference of some 8 mas (~0.001%). Here we report the most accurate observations to date of the solar shape, which show a much larger apparent oblateness with an equator-pole radius difference of 13.72± 0.44 mas. This new component can easily be distinguished spatially from the effects of faculae in the active latitude zones. Comparison with earlier observations suggests that this excess oblateness results from solar magnetic activity, as do the frequency variations of the helioseismic modes.
Here is a more popular account:
http://science.nasa.gov/headlines/y2008/02oct_oblatesun.htm
The point is that the hills and corrugations are more pronounced [‘bigger sun’] at solar maximum when magnetic activity is highest.
A lot of the heioseismic modes are subharmonics of a 5 minute lightspeed wave. The inner planets also (allowing a bit of latitude for inter-orbital settlement) lie on the nodes of a 5 minute wave. There is only a 7 degree difference between the planetary plane and the solar equatorial plane. It would be interesting to know if the observations are sufficiently sensitive to be able to determine whether the maximum oblateness is on the solar equatorial plane or the on the plane of invariance. This might go some way to settling the question of whether the changing oblateness is purely an internal ‘sun thing’ or whether the planets are also involved. Do you think the new experiment might be able to resolve that?
Further analysis of the RHESSI data:
http://news.softpedia.com/news/Sun-039-s-Sphere-Is-Not-Perfect-94896.shtml
Shows that if you subtract the extra oblateness due to magnetic features, the result is precisely what is expected from simple rotation, so no adjustment of solar models, interior structure, planetary tides, or general relativity is required.
The quantification of the displacement of matter in the sun due to magnetism would seem on the face of it to be an issue which would have to have quite a few assumptions built into it. It may well be right, but I think that to exclude other possibilities on this basis would be to unecessarily limit the options for understanding. Does the current mainstream theory of the sun have an explaination for why there is an ~eleven year periodicity in the cycle of increasing/decreasing oblateness and magnetic activity?
Thanks as always for your time, knowledge, humour and patience Leif.
Considering it some more, I think that even if the standing waves or ‘hills’ were being brought about by an interaction between the motions of the planetary masses above and below the solar equatorial plane and the matter in the sun, the centrifugal forces within such a fluid body would pull the oblateness changes into line with the solar equatorial plane.
Perhaps a more subtle way to detect possible influence would be to analyse the relative preponderance of northern and southern hemisphere sunspots for cyclicities.
Is there any data on that which is accessible by us Leif?
I really ought to read the links you provide before littering WUWT with extra posts Leif. The NASA link shows an interesting diagram of oblateness which definitely isn’t in line with the solar equator. It’s a shame the diagram doesn’t provide any clues as to what it might be in line with though…. I’ll track down the paper to see if it lets us know where in the sky the satellite was when it made the 10 day reading.
Thanks hugely, Leif, for the reference to the Fivian, Hudson, Lin and Zahid paper. I will study it carefully. We do live in exciting times!
I thought it might be interesting to note another take on geomagnetic activity in the last century. The attached paper supports Leif’s analysis but goes onto show “that geomagnetic activity has increased during the last century at all stations. Also, the Ah indices prove our earlier finding that the amount of centennial increase varies greatly with latitude, being largest at high latitudes, smaller at low latitudes and, quite unexpectedly, smallest at mid-latitudes.”
http://spaceweb.oulu.fi/~kalevi/publications/Martini_Mursula_JASTP_2008.pdf
Centennial geomagnetic activity studied by a new, reliable long-term index – D. Martini and K. Mursula – Journal of Atmospheric and Solar-Terrestrial Physics 70 (2008) 1074–1087
Could this explain some of the arctic melt I wonder and indeed the warming trend that we have seen through the latter part of the century?
You forgot the silly walk…
Leif (19:02:14)
The Argentinian movie ‘Hombre Mirando al Sudeste’ is about an institutionalized man who believes he’s alien and receives direction from the southeast. My precis doesn’t give enough credit to the excellence of the film. Thanks for the link about the oceanic oscillations. It’ll all be in there with clouds and some spectra of energy from the sun. After all: The sun is very sultry and we must avoid its ultry-violet rays.
H/t N. Coward
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tallbloke (01:15:14)
I may be mistaken, but I believe one of those minimums had its few large spots in the southern hemisphere only.
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PaulHClark (02:59:11) :
I thought it might be interesting to note another take on geomagnetic activity in the last century. The attached paper supports Leif’s analysis but goes onto show “that geomagnetic activity has increased during the last century at all stations. Also, the Ah indices prove our earlier finding that the amount of centennial increase varies greatly with latitude, being largest at high latitudes, smaller at low latitudes and, quite unexpectedly, smallest at mid-latitudes.”
The authors are misleading you [and their readers]. The first claim is disingenuous, because the last century goes from 1901 [a minimum year] to 2000 [a maximum year]. If they have extended the analysis through 2008 they would have found that activity now is as low as in 1901. The second claim just shows that they do not understood their own index. Solar activity and the Earth’s magnetosphere’s reaction to it does not depend on the latitude of the measuring station. As explained in section A5 [and figure A6] of http://www.leif.org/research/2007JA012437.pdf the second claim is spurious because of changes in the Earth’s magnetic field.
tallbloke (00:54:53) :
The quantification of the displacement of matter in the sun due to magnetism would seem on the face of it to be an issue which would have to have quite a few assumptions built into it.
No, this is an observational fact. The assumption is that what we observe is what happens.
Does the current mainstream theory of the sun have an explaination for why there is an ~eleven year periodicity in the cycle of increasing/decreasing oblateness and magnetic activity?
Indeed, yes we do. We are quibbling about the details, but they are just that: details.
@tallbloke (04:01:15) who said “Since we agree … there is a good correlation between solar activity and global temperature … we can safely conclude that it solar which is the cause and earth temperature which is the effect.”
Wrong, or at least not totally correct. For any correlation between S & T, there are always four possible reasons:
1. S causes T.
2. T causes S.
3. S & T are caused by X.
4. S & T only happen to correlate by accident (random chance).
So while it is true that global temperature cannot affect sun activity (which rules out reasons 2 & 3), we cannot be sure that 1 is the answer, because there is still option of 4.
While I do *favour* sun spots (due to sun activity) causing temperature, IMHO 150 years of inexactly correlating data is not enough for be totally sure:
http://www.woodfortrees.org/plot/hadcrut3vgl/from:1850/mean:132/plot/sidc-ssn/from:1850/mean:132/scale:0.01/offset:-0.8
If we could find the “other factors” that influence global temperature, and remove their effect, then it would be much easier to be sure whether sun activity is the main cause of global temperature variations.
BTW, one nice reason for choosing sun spots over some other proxy of sun activity, is that sun spots have been explicitly recorded by man, while “sun activity proxies” may be measuring something other than what you think (just like tree rings & temperature).
Because of the semiannual variation of geomagnetic activity [which has nothing to do with solar activity] ap is 25% lower near the solstices [e.g. December], so when comparing single data points that has to be taken into effect.
Leif
Thanks – I clearly need to do more reading and I really appreciate you taking the time to respond.
As ever, deeply grateful for your input.
Does the current mainstream theory of the sun have an explaination for why there is an ~eleven year periodicity in the cycle of increasing/decreasing oblateness and magnetic activity?
Indeed, yes we do. We are quibbling about the details, but they are just that: details.
Quick praisee or a linky? 🙂
I’d really appreciate an answer to this one below:
Perhaps a more subtle way to detect possible influence would be to analyse the relative preponderance of northern and southern hemisphere sunspots for cyclicities.
Is there any data on that which is accessible by us Leif?
tallbloke (11:06:23) :
Quick praisee or a linky? 🙂
http://www.sciencemag.org/cgi/content/full/322/5901/560
is a good place to start.
analyse the relative preponderance of northern and southern hemisphere sunspots for cyclicities. Is there any data on that which is accessible by us
Yes, you have to do some work, but Hathaway’s website has all you need back to 1874:
http://solarscience.msfc.nasa.gov/greenwch.shtml
A simple plot since 1945: http://sidc.oma.be/html/wnosuf.html
A google search on ‘north south asymmetry sunspots’ gives you lots of pointers. Most of the papers pointed to are of low or mediocre quality [as most cyclomania stuff is].
E.M.Smith (17:53:33) :
Luigi (12:00:08) :
So can draw a relationship for the lowest point for Solar Geomagnetic Ap Index and the economy!? or the beginning of the green house effect?
[…]
The theory is that the lower output of light and cooler temps lead to lower agricultural output and that (hand waving) translates into lower demand for tractors, cars, train shipping etc. thus modulating the business cycle.
Found an example. I’ve Bolded the temperature bit. From last year, an announcement by Maui Land & Pineapple:
Maui Land & Pineapple swings to 1st-quarter loss
By Robert Daniel, MarketWatch
Last update: 6:18 a.m. EDT May 4, 2008
TEL AVIV (MarketWatch) – Maui Land & Pineapple Co. swung to a first-quarter loss from a year-earlier profit on fewer land sales and weaker operations in fresh-pineapple sales.
The Kahului, Hawaii, company (MLP) posted a loss of $740,000, or 9 cents a share, compared with net income of $15.7 million, or $2.12, for the year-earlier period. Shares outstanding rose 6.1% to nearly 8 million.
Revenue slumped 58% to $25.4 million from $61 million.
The company said in a statement late on Friday that its revenue from land sales is sporadic, so figures in one quarter may not reflect the results for a full year.
In addition, colder-than-average temperatures at its plantation in Hali’imaile meant its fruit took longer to ripen. The agriculture segment thus reported an operating loss of $5.6 million, wider than the $2.4 million year-earlier deficit.
Supposedly, repeated thousands of times around the planet and filtered through the rest of the economy and the warm / cold flip drives a rich / poor flip.
Chris H (07:59:13) :
1. S causes T.
2. T causes S.
3. S & T are caused by X.
4. S & T only happen to correlate by accident (random chance).
So while it is true that global temperature cannot affect sun activity (which rules out reasons 2 & 3), we cannot be sure that 1 is the answer, because there is still option of 4.
Um I think that T not=> S only rules out #2. #3 ought to stay in since, as a bogus hypothetical, our solar system position relative to the galactic plain might drive both S & T (i.e. be X) and is not falsified by T not driving S.
That little nit harvester, me … 😉 (Anyone remember “That little Wine Maker” tag line from long long ago commercials?…)
@E.M.Smith (13:58:32)
I didn’t explain why reason for #3. There are two cases for X:
(A) X originates on Earth.
(B) X originates in space (e.g. the Sun).
Clearly X cannot affect the Sun if #A is true, which is why I said it “rules out reasons 2 & 3”.
Where-as if #B is true, then it doesn’t really matter whether X originates in the Sun (most likely) or whether somewhere else in space, since for the argument in question we are only interested whether something outside Earth is causing temperature changes (reason #1) or not (reason #4).
Chris H
So while it is true that global temperature cannot affect sun activity (which rules out reasons 2 & 3), we cannot be sure that 1 is the answer, because there is still option of 4.
If we could find the “other factors” that influence global temperature, and remove their effect, then it would be much easier to be sure whether sun activity is the main cause of global temperature variations.
I agree with E.M. Smith that logically (3) is still in play, but notwithstanding the gas giant baby elephants in the room which I’m sure have an influence on modulating the cycle, the sun is still the big boy on the block.
The “other factors” are mainly the big battery oceanic cycles, whichever way their ~60 year cycle is modulated (Albedo, GLAAM, lunar modulated wind patterns, insert favourite hidden driver here). Their quasi periodicity certainly skews the direct solar-temperature correlation, but in the end, more energy comes from the sun than comes out of the earths core by a factor of lots of OOM.
It’s the most fascinating puzzle ever, and by swapping ideas and progressed data, we’ll get there.
I’d still like to try to squeeze six solar cycles into the approx. 60 year cycle of the PDO, then find something, like the shape of cosmic ray peaks, that alternates in solar cycles, leaving three solar cycles in each 30 year heating or cooling phase of the PDO. I don’t think it fits very well, though, and, of course, I lack a mechanism how shapes of cosmic ray peaks alternately cool and heat oceans.
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Thanks Leif,
I will download the North and South data from Hathaway’s site and start playing with R.
Found this paper which looks useful too if you are familiar with it please comment.
The Long-term Behavior of the North – South
Asymmetry of Sunspot Activity
K.J. Li · P.X. Gao · L.S. Zhan
kim (04:03:01) :
I’d still like to try to squeeze six solar cycles into the approx. 60 year cycle of the PDO, then find something, like the shape of cosmic ray peaks, that alternates in solar cycles, leaving three solar cycles in each 30 year heating or cooling phase of the PDO. I don’t think it fits very well, though, and, of course, I lack a mechanism how shapes of cosmic ray peaks alternately cool and heat oceans.
Kim,
You may also want to look at the ~60 year fluctuations in Global atmospheric angular momentum (GLAAM) and it’s correlation with Length of Day (LOD).
tallbloke (04:53:41) :
The Long-term Behavior of the North – South
Asymmetry of Sunspot Activity
Is typical of the scores of papers on this subject [I have one myself coming out shortly]. Nothing significant has ever emerged from these studies. Here is another one of the same ilk: http://www.chjaa.org/Papers_Accepted/08072_arnab_v2.pdf
Leif Svalgaard (09:06:30) :
Because of the semiannual variation of geomagnetic activity [which has nothing to do with solar activity] ap is 25% lower near the solstices [e.g. December], so when comparing single data points that has to be taken into effect.
I wonder just how much this effect is contributing to the current historic
low in the Ap index. Will be another interesting item to watch over the next several months.
Paul
Thanks Leif,
interesting that all the studies I’ve looked at so far treat the asymmetry over complete 11 year cycles, rather than the Hale cycle. You’d think that the magnetic polarity would have a bearing on this somehow. Also, I think an analysis of the predominance of one hemisphere over the other on the ascending and descending parts of the cycles might be worth checking too. Are you aware of any previous studies which have taken either of these two periods into account?