A guest post by Jeff Id
Well John Christy gave me a lot to think about in satellite temp trends as far as an improved correction over my last post. Steve McIntyre pitched in some comments as well. It is going to take a bit to work out the details of that for me but I think I can produce an improved accuracy slope over my last posts. In the meantime, I downloaded sunspot numbers from the NASA.
Cycles are interesting things. There are endless cycles in nature, orbits, ocean temp shifts, solar cycles, magnetic cycles the examples are everywhere. What makes a cycle unusual is also an interesting topic. Some solar scientists have claimed that our current solar cycle is not unusual by the record. They are certainly the experts but recently the experts have been forced to update their predictions for the next solar cycle.
Well, I’m no expert on the sun but I do find the data regarding sunspots interesting, particularly in the fact that we are again in at least a short term cooling at the same time sunspots and solar magnetic level have plunged.
Here’s an article from our all understanding US government.
What’s Wrong with the Sun? (Nothing)
And a few beginning lines.
July 11, 2008: Stop the presses! The sun is behaving normally.
So says NASA solar physicist David Hathaway. “There have been some reports lately that Solar Minimum is lasting longer than it should. That’s not true. The ongoing lull in sunspot number is well within historic norms for the solar cycle.”
Cool picture …….
See where the tiny little 2009 tick is. We should be increasing now and well on our way by 2010. By the way, this is an updated graph from the original predition.
Hathaway said, well within historic norms. Forecasting is the most dangerous sport, but I am as curious about this claim as any —he is the expert after all. Here’s a plot of the sunspot data from NASA NOAA numbers.
I did a sliding slope fit to the data to find when the slopes shifted from negative to positive in each cycle. I placed a red line above each point identified. These points are not intended to mean the beginning of a cycle( that is for the experts) but rather to be a consistent software identified point between each cycle.
The red lines represent solar minima. The only line which may not be a minima is the most recent in Jan 09 which we need to reference how unusual solar activity is.
Below is a list of the years the red lines are centered on.
1755.667, 1766.250. 1775.583, 1784.500, 1798.167, 1810.583, 1823.167, 1833.833, 1843.833, 1856.167, 1867.167, 1878.750
1889.500, 1901.750, 1913.167, 1923.417, 1933.750, 1944.167, 1954.250, 1964.833, 1976.250, 1986.250, 1996.417, 2009.041
The years between each minima are currently
10.583, 9.333, 8.916, 13.666, 12.416, 12.583, 10.666, 10.000, 12.333, 11.000, 11.583, 10.750, 12.250, 11.416, 10.250, 10.333,
10.416, 10.083, 10.583, 11.416, 10.000, 10.166, 12.625
So far there has been only one solar cycle which has exceeded the length of the current one. The cycle extended extra long (13.66 years) from 1784 – 1798 and was the last cycle leading into the Dalton Minimum.
A histogram of the distribution of the time between solar cycles looks like this.
The standard deviation of the total record is 1.18 years the mean is 11.01. Well there’s the eleven year solar cycle we hear about.
Two sigma (two standard deviation) difference from the mean corresponds to a 95% certainty of something unusual in our current situation. The numbers this year at mid Jan correspond to about 1.37 sigma of all time records, which is getting close. But that’s not the end of the story, after all I just included the dalton minimum cycles in the data right after we identified the solar cycle prior to the dalton minimum as the one with the longest time span on record. That means, I treated it as though it were a normal event. —– Well I do believe (on faith in nature) this length is normal, the sun isn’t doing anything different from before but there is only one of these long events on record and were we to look for a similar event it would be stupid to include it in the standard deviation dataset. We should only look at data which is not related to another potential dalton minimum from Figure 2 this would be after the dalton minimum and before present day (from 1833 – 1996).
The standard deviation of the cycle start after the dalton minimum 1833 and before 2009 was only 0.79 years. The average Jeff Id solar cycle in the same period is 10.83 years. This puts the two sigma limits of the solar cycle at 9.26 years on the short side and 12.42 years on the long side.
Of course this puts my reasonable analysis of solar cycle outside of the last 176 year normal to a two sigma 95% interval 12.6 years has crossed the limit. With little sign of the next cycle beginning yet, this might get worse. I tell you what, I prefer the taxes from global warming to the cost of glaciers in my yard, it seems like a balance of evils to me. I hope this solar cycle changes soon but we can no more effect the sun with a dance than we can effect global warming with a tax so what choice do we have.
In Dr. David Hathaway’s defense, he made his statement above in July which put the current minimum at 2008.583 which comes to 12.166 years and just inside the 95% two sigma certainty of 12.42.
Now that we’re at 12.6, I wonder if they’ll extend the predictions for the beginning of the next cycle again.
Then again, you could lop off the whole right side of the histogram and then recalculate…that would show them. I don’t believe that eliminating or manipulating inconvenient data is any more fruitful in sunspot analysis than it is in temperature records.
Werner Weber (22:39:30): “… solar irradiance variations alone are far too small to account for the measured changes in global temperature.”
The oceans make up the bulk of the difference. Those who say that the 20th century warmed by 0.65 or 0.7 C are measuring from a cooling period to the near peak of a warm spell. The bulk of the measured changes in global temperature are from the oceans. The 0.15 C of warming caused by the increase in solar irradiance is almost half of the warming when you filter out the ocean cycles’ noise.
Jeff, I wonder if you exclude data from the long end, then should you not exclude outliers from the short end too?
JOhn M Reynolds
I wasn’t aware that the sun had a “Conveyor Belt.” What is this, how did they find it and how do they know it’s slowed down?
Leif (23:59:26)
So his method, slope change, gives a whole year longer than your method. Why should ‘dominance of spots’ be so different than slope change?
I like the method of minimum definition which you mentioned months ago, something like ‘when the curve just lies dead flattest’, which would make this latest, August of ’08, by my estimation.
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Bill Illis (04:44:40) :
…
There is some strange repeating cycle in temperatures (and even sunspots) at 25 years lag.
Bill, what data are you seeing this in? In the HadCRUT3 global series, there’s a ~20-21 year cycle, and there is a fair amount of previous literature on this. I’ve seen occasional references to 25 years, but don’t have any references handy. If your data set is accessible, I can do an MTM spectrum analysis on it to see what we find.
BTW, anyone interested in weather cycles really should read
http://www.amazon.com/Weather-Cycles-William-James-Burroughs/dp/0521528224
He has a good discussion of the evidence for solar influence on weather.
Referencing JDS and crosspatch: perhaps the Gore Minimum is being caused by a proliferration of refrigerator magnets reminding people everywhere to check and make sure their tires are properly inflated.
I think there is a correlation here.
is it possible to have double minima??
————-
Dead cat bounce?
If we are entering a new solar minimum, shall we call it the Hansen Minimum or the Gore Minimum? Or perhaps the Hansen/Gore Minimum.
2-sigma = 95%.
1-0.95 = .05
1/.05 = 20
We should expect about 1 in 20 cycles to exceed the 2-sigma number.
How many cycles has it been since the last 2-sigma event?
19
Cycles 3-4 to cycles 4-5 minimum difference = 13.666 years, from Anthony’s analysis above.
Eyeballing the histogram, it is close to a Normal distribution, but it appears to have more weight on the high side, perhaps the cycles are modal. No cycles since 1750 have a 2-sigma event on the low side (8.65 years).
My conclusion: Nothing unexpected is happening.
The “analysis” by Jeff appears to contain at least one fundamental flaw. Here are a couple of issues to address:
1. Here’s a zoom in on the sunspot data – http://img187.imageshack.us/my.php?image=picture17ks7.png
Jeff says the minimum for the 90s happened at 1996.417 – does that look right? It may be “righter” than it appears, but that would require Jeff to tell us what kind of smoothing function or fit was used to extract the local minima for his red lines. The position of the minimum can move around by half a standard deviation depending on whether you use a linear smoothing function (over some n points), or an FFT-smooth, or a fit to quadratic or cubic spline, or if you just pick the actual minimum from the raw data. I’ve never heard the term “sliding slope fit” before, so maybe Jeff will tell us what it means.
2. The local minimum for the current decade may have already passed us by last summer, for all we know. Here’s the monthly data for the last 12 months:
2008 01 3.3
2008 02 2.1
2008 03 9.3
2008 04 2.9
2008 05 3.2
2008 06 3.4
2008 07 0.5
2008 08 0.5
2008 09 1.1
2008 10 2.9
2008 11 4.1
2008 12 0.8
The local minimum was in Jul-Aug of 2008, yet Jeff assumes that the current minimum happens no sooner than Jan 2009.
The actual time interval between the raw minima (not a very useful number, but hardly worse than anything else that can be had for at least a few more months) is about 11.8 years. That’s well inside the 2-sigma interval for even the post-Dalton-Minimum period.
Well, I forgot to close the em bracket in my previous post. Mod, stick a close em bracket after “lag.”
Meanwhile,
Jeff, you may be teaching an old dog a new trick. What do you mean by “sliding slope fit?” Can you give me more information about that?
Pretty much any kind of spectrum analysis shows the bimodal nature of sunspot cycle length. Even if Leif is correct about these matters (but see my question to him to follow), I still think it is notable (I’d normally say “significant” but you have to be careful saying that in a context where we’re talking statistics) that this transition makes it look like we’re moving from a regime of short, strong cycles — 16-23 — back to a regime like that of 10-15, possibly longer, weaker cycles. I know Leif doesn’t approve, but I like the way this diagram shows it:
http://users.telenet.be/j.janssens/Spotless/Spotlessevolution.png
(In fairness, Leif’s view of the data is this is in the last three graphs of this document:
http://www.leif.org/research/Most%20Recent%20IMF,%20SW,%20and%20Solar%20Data.pdf )
Werner Weber (22:39:30) :
“Whenever you invoke the sun as driver of climate variations, you may find a lot of correlations such as Maunder minimum and little ice age, but solar irradiance variations alone are far too small to account for the measured changes in global temperature. ”
If climate is a chaotic system it could be that the slight changes in the sun are just enough to push earth’s climate toward different attractor states.
However, this still does require a cause and effect. Chaos is still a deterministic process and there must be REAL physical processes involved. Cosmic rays could be the answer, or a combination of factors, who knows.
M Morris (05:21:06) :
“I’m certainly no expert on climate studies but i have always been interested in the unpredictability of stochastic systems and chaos theory.
What i dont understand about all these supposed predictions from the Met office and other so-called climate experts is how they can claim with any degree of credibility that such unpredictable systems can be modelled accurately or predictions can be made that are anything other than a lucky shot or guess.”
My impression is scientists are assuming the earth’s climate has *enough* primary drivers so that the chaos can be understood. In other words, unlike weather, it’s really not all that chaotic over the short term (which may be many decades in climate).
Thanks to everyone for the comments.
As far as lopping off data or similar comments- If you want to look for an unusually long event which may lead to a minimum (only one example in this record) it doesn’t make sense to include it in the SD analysis. I included the whole dataset in the analysis as well so there’s nothing hidden.
Lief’s criticism is valid. However I believe by my analysis that because I looked for minimum slope, the most recent line in 2009 won’t shift back in time much even if the next cycle really starts going vertical making spots next month. It also visually looks longer at this point.
Perhaps tonight I’ll put the predicted data in the set as presented by Hathaway and see how it compares with history. The predictions have been forced out enough that he may have been predicting a 95% event already.
“Perhaps it’s time to re-visit the ideas of Dr. Theodor Landscheidt”
Probably not. For example. While the 11 year cycle is somewhat analogous to the orbit of Jupiter, I don’t believe a solar scientist would say that the orbit of Jupiter is responsible for the cycles. And while Landscheidt might have noticed something happening at particular intervals, what he proposes as the cause is probably not it. His plotting of these intervals and how they correspond with events is, however, uncanny.
Re: M Morris (05:21:06)
Hold a piece of paper up in the air in a light breeze. When you let go you can predict in what direction it will go (climate) but not how it gets there (weather). You can predict roughly where it will land but not with any degree of certainty or accuracy. The models basically claim the direction is up but cant predict the path we take to it.
Now in order to predict where the paper will land with any degree of accuracy you would need to know the following:
1. Height above the ground.
2. Surface area of the paper.
3. Dimensions of the paper.
4. Weight of the paper.
5. How flexible the paper is.
6. Friction coefficient of the paper.
7. Atmospheric pressure
8. Humidity.
9. Wind speed
9. Wind direction.
10. Air temperature.
etc etc.
The effect of changing some of these values has on the final resting position will depend upon how far the paper has to drop. Drop it from 6 inches and you only really need to know windspeed and direction. From 6 feet and a lot more parameters have a measurable effect. From 60 feet and it is a near impossibility to predict. Now consider the difference in complexity between the climate and dropping a piece of paper, which why I think all climate models, no matter how accurate with past climate, are useless when it comes to predicting anything.
Oh, and one other thing, the climate models have assumed that there is only one source of the wind and its direction is up.
Trevor (00:09:46)
I read the Landscheidt paper and it certainly struck a chord with me. Over the last several weeks I have read extensively around the subject matter of links with solar geomagnetic activity and earth climate and this has taken me down the path of learning more about the Gleissberg cycle and its relevance.
I would assign a high probability that the thesis in the Landscheidt paper you linked to contains evidence that will be highly relevant as our understanding develops.
I would encourage others to read the paper and form their own judgement.
I’ll just suggest it gently again. Common sense tells me that a lot of sun energy gets through to our atmosphere when there are solar flares and CMEs. That energy will find a way to heat the lower atmosphere. Forget TSI. I admit that flare energy would be hard to measure as an event, but it doesn’t make it any less real.
Let’s see what happens to our temperatures over the next years without this extra energy.
coaldust,
I don’t know if anyone here believes the sun is behaving unusually. That is actually the point made here so often, the last time nothing unexpected happened was cycle preceding the Dalton minimum (also a normal event I believe). You combine that with the reduced magnetic activity since 2005 and it leaves me wondering how much effect we’ll see on our climate in the near future.
Leif Svalgaard (23:59:26) :
Leif Svalgaard (23:03:19) :
one might make an argument for minimum in July or August 2008
And by the same criterion [ see http://www.leif.org/research/Most%20Recent%20IMF,%20SW,%20and%20Solar%20Data.pdf ] the previous minimum was 1997.0, so the cycle length should be 2008.6 – 1997.0 = 11.6 which is less than one sigma from the mean [using the figures given: 10.86+/-0.79].
Leif, looking at the charts on Page 4 of the solar cycle transitions, how did you calculate your “yearly smoothed” values?
“we haven’t had a cycle 23 sunspot for months, all the recent ones have been cycle 24. My guess for the minimum on the boxcar basis is October 2008 ”
And that minimum is moving forward due to the marked asymmetry between 23 and 24. The panel uses a number of criteria discussing their ‘definitive’ minimum including coronal holes and IMF tilt.
Re-reading Janssens I see one remaining resort to hope for Hathway in his latest estimate for Rmax.
“About 200 years ago, a most curious series of solar cycles occurred. The 2 shortest cycles – both of them did not last 9 years- were followed by cycle 4, which would itself last for over 14 years and became so the longest lasting of the entire official series. This trio also belongs to the active solar cycles, with maximum Wolfnumbers between 125 and 165. It was thereforeall the more remarkable that they were followed by 2 cycles with a maximum Rz that hardly reached 50. This period is called the Dalton minimum, and it lasted approximately from 1795 till 1825. The somewhat more active cycle 7 ended these interesting series, with the peculiarity that the time of rise was 50% longer than the time of fall (respectively 6 and 4 years).”
Note that cycle 5 (24 twin?) is also backward in rise to run. If 24 follows this form Rmax might be delayed to mid-2014 even if we are on its ‘rise’ at present.
The sun is slowing down in many ways, and it seems a little silly to argue that “nothing unusual is happening” unless unusual has to mean that the sun explodes or blinks out.
I do want to point out that the sunspot data is averaged (we only count spots facing the Earth – so some averaging is certainly required.) Typically, this data is averaged over a 1 year period centered over the current month. Thus, you will not know the average for today until 6 months from now.
Jan09 is probably not the averaged minimum. I suspect that Aug08 will be the future averaged minimum – but we will not know this for at least another 6 to 9 months.
To do this analysis now – all you can claim is a 12.15 year long cycle for 23 (setting the minimum in July08, which is technically possible if late Jan09 and Feb09 etc. suddenly have many large spots). 12.6 is probably incorrect.
Anthony,
Not sure if you can change that graphic of the sun cycles (first pic) but that arrow that says “You are Here” is off…by about 6 months it looks like. Each tick is a year, and if we are saying January 2009 then it needs to be moved right. In that case, also, we should be juuuust beginning the upswing back to the land of lots of spots. I assume that graphic has not been updated since the summer because the actual sunspot graphing versus predicted trend-line stops about mid 2008.
As there have been updates to forecasts, might we not add in an updated graphic? Unless July 2008 was the lastest prediction from Dr. Hathaway.
REPLY: That is Dr. Hathaway’s graphics from that date, I will not modify it. – Anthony
I’d have to agree with coaldust. I did an analysis kind of like Jeff id (choosing end/beginning points of cycles based on change from – to + slope) using data up to the end of 2008. However, to better visualize the difference between solar cycles, I overlaid all of the cycles on top of each other using the min between each cycle as the starting point. Here is the pic:
http://tinypic.com/view.php?pic=30ndy1c&s=5
Based on the graph I linked to, the length of SC23 is very similar to cycles 8, 10, 12, and 13, which occurred during the middle to late 1800s.
Any mention of the barycenter concept should mention the late Rhodes W. Fairbridge along with Theodor Landscheidt.
See, for example:
http://www.griffith.edu.au/conference/ics2007/pdf/ICS176.pdf
Fairbridge represents the mainstream, established defender of the barycenter theory. He was one of the most respected Australian geologists. Landscheidt was something of an outsider, and originally an astrologer. But such work looks like it could easily be checked today.
Pasi (06:44:01) :
I wonder if any of you guys is a friend of NASA’s David Hathaway and could invite Mr. Hathaway to give his comments on this topic here?
Pasi: Leif’s worked with Dr. Hathaway, and has said that Dr. H is usually pretty busy.