NASA's Hathaway issues new solar cycle prediction

Geoff Sharp writes in comments:

NASA releases their new estimate for SC24. The new number is 64 but not allowing for any 13 month smoothing is noted.

The text is quite comical, they have no idea. By Xmas I predict they will be inline with my prediction made in 2008.

Perhaps. This blink comparator that I made (see below), tells the story pretty well.

Back in October of 2007, the SC24 smoothed SSN prediction was for 150. Now it is 64. But, let us not be too critical of Dr. Hathaway, unlike some scientists we know, he has the integrity and courage to admit when his forecasts and models don’t work, and to revise them in the face of reality. Speaking from experience, Nature can be a bitch to forecast.

Here’s the current prediction below:

Solar Cycle Prediction

(Updated 2010/10/05)

ssn_predict.gif (2208 bytes)

Current prediction for the next sunspot cycle maximum gives a smoothed sunspot number maximum of about 64 in July of 2013.

Predicting the behavior of a sunspot cycle is fairly reliable once the cycle is well underway (about 3 years after the minimum in sunspot number occurs [see Hathaway, Wilson, and Reichmann Solar Physics; 151, 177 (1994)]). Prior to that time the predictions are less reliable but nonetheless equally as important. Planning for satellite orbits and space missions often require knowledge of solar activity levels years in advance.

A number of techniques are used to predict the amplitude of a cycle during the time near and before sunspot minimum. Relationships have been found between the size of the next cycle maximum and the length of the previous cycle, the level of activity at sunspot minimum, and the size of the previous cycle. Among the most reliable techniques are those that use the measurements of changes in the Earth’s magnetic field at, and before, sunspot minimum. These changes in the Earth’s magnetic field are known to be caused by solar storms but the precise connections between them and future solar activity levels is still uncertain.

Of these “geomagnetic precursor” techniques three stand out. The earliest is from Ohl and Ohl [Solar-Terrestrial Predictions Proceedings, Vol. II. 258 (1979)] They found that the value of the geomagnetic aa index at its minimum was related to the sunspot number during the ensuing maximum. The primary disadvantage of this technique is that the minimum in the geomagnetic aa index often occurs slightly after sunspot minimum so the prediction isn’t available until the sunspot cycle has started.

An alternative method is due to a process suggested by Joan Feynman. She separates the geomagnetic aa index into two components: one in phase with and proportional to the sunspot number, the other component is then the remaining signal. This remaining signal has, in the past, given good estimates of the sunspot numbers several years in advance. The maximum in this signal occurs near sunspot minimum and is proportional to the sunspot number during the following maximum. This method does allow for a prediction of the next sunspot maximum at the time of sunspot minimum.

A third method is due to Richard Thompson [Solar Physics 148, 383 (1993)]. He found a relationship between the number of days during a sunspot cycle in which the geomagnetic field was “disturbed” and the amplitude of the next sunspot maximum. His method has the advantage of giving a prediction for the size of the next sunspot maximum well before sunspot minimum.

We have suggested using the average of the predictions given by the Feynman-based method and by Thompson’s method. [See Hathaway, Wilson, and Reichmann J. Geophys. Res. 104, 22,375 (1999)] However, both of these methods were impacted by the “Halloween Events” of October/November 2003 which were not reflected in the sunspot numbers. Both methods give larger than average amplitude to Cycle 24 while its delayed start and low minimum strongly suggest a much smaller cycle. The smoothed aa index reached its minimum (a record low) of 8.4 in September of 2009. Using Ohl’s method now indicates a maximum sunspot number of 70 ± 18 for cycle 24. We then use the shape of the sunspot cycle as described by Hathaway, Wilson, and Reichmann [Solar Physics 151, 177 (1994)] and determine a starting time for the cycle by fitting the data to produce a prediction of the monthly sunspot numbers through the next cycle. We find a starting time of August 2008 with minimum occurring in November or December 2008 and maximum of about 66 in June of 2013. The predicted numbers are available in a text file, as a GIF image, and as a pdf-file. As the cycle progresses, the prediction process switches over to giving more weight to the fitting of the monthly values to the cycle shape function. At this phase of cycle 24 we now give 22% weight to the curve-fitting technique of Hathaway, Wilson, and Reichmann Solar Physics 151, 177 (1994). That technique currently gives highly uncertain (but smaller) values.

Note: These predictions are for “smoothed” International Sunspot Numbers. The smoothing is usually over time periods of about a year or more so both the daily and the monthly values for the International Sunspot Number should fluctuate about our predicted numbers. The dotted lines on the prediction plots indicate the expected range of the monthly sunspot numbers. Also note that the “Boulder” numbers reported daily at www.spaceweather.com are typically about 35% higher than the International sunspot number.

Another indicator of the level of solar activity is the flux of radio emission from the Sun at a wavelength of 10.7 cm (2.8 GHz frequency). This flux has been measured daily since 1947. It is an important indicator of solar activity because it tends to follow the changes in the solar ultraviolet that influence the Earth’s upper atmosphere and ionosphere. Many models of the upper atmosphere use the 10.7 cm flux (F10.7) as input to determine atmospheric densities and satellite drag. F10.7 has been shown to follow the sunspot number quite closely and similar prediction techniques can be used. Our predictions for F10.7 are available in a text file, as a GIF image, and as a pdf-file. Current values for F10.7 can be found at: http://www.spaceweather.ca/sx-4-eng.php.

Here’s my blink comparator:

Advertisements

87 thoughts on “NASA's Hathaway issues new solar cycle prediction

  1. Is Leif still holding to his 72 prediction? Leif has there been anything that indicates to you that you would reduce your own prediction number? Also, even Hathaway and others from the NASA team had previously predicted a very low cycle 25, is this still the case?

  2. He still has it wrong. We’re looking at a peak in 2016 and a an end to the cycle in 2022 or so. I’ll also venture that solar activity will have more powerful solar storms, but less frequent.
    The key is the next solar cycle. If that one tanks, like the current cycle, it doesn’t bode well for our current warm temperatures.

  3. Sunspot predictions, best to wait until cycle 25 to predict what 24 will be. It’s become that kind of sun — Maybe the sunspot numbers aren’t that predictable after all.
    Can you imagine what the predictions must have looked like during the Maunder Minimum. No offense to the prediction folks, but it is not an exact science and fraught with peril.

  4. In Feb ’09, Solaemon collated 45 predictions for cycle 24, With Rmax ranging from 50 to 169. Anyone claiming their early prediction is any better than a lucky guess needs to explain why their method was demonstrably better when they made their prediction.
    This NASA prediction should be in the ‘once the cycle has started’ range, so more accurate, but still assuming that solar behaviour is following the same pattern as has been observed in the past. Remember that the cycle still has a good few years to run so a good prediction now is valuable for many commercial uses even if the earlier projections were pessimistic. (I think high is expensive for satellites in terms of both shielding and drag)

  5. If somebody changes his/her prediction every day, it is not a prediction, but a joke or a childish game, and it transpires that he/she knows not what law operates behind.

  6. Hi!
    Too bad the “blink” comperator is scaled differently.
    The old prediction goes to 2015, the new prediciton to 2020.. :(..
    Could you fix?
    HLx

  7. > let us not be too critical of Dr. Hathaway,
    Absolutely – I’m mystified by the folks who expect that a prediction should be made and never updated. If I go watch the weather segment on the nightly news, I don’t want to see tomorrow’s forecast be from the five day forecast four days ago. Nor do I ridicule that forecast unless I think I can do a better job. Even then understand why that forecast was made is better than ridiculing it.
    To gauge the accuracy of long term predictions, people will just have to make a matrix of date of prediction and the prediction. Easy enough to do and can be done without whining. Look at the bright side – we’re learning a lot about the Sun thanks to SC24.
    Hathaway’s prediction is now below Leif’s – is that a first for SC24 for that comparison?
    Given that we appear to be losing sun spots to the Livingston/Penn effect, we should be giving more note of 10.7 cm predictions. Hathaway’s latest is at http://solarscience.msfc.nasa.gov/images/f107_predict.gif in is calling for about 120 (123.3 in his .txt file) in a range of 100-150. SC23 reached 180.

  8. @Vuk etc.
    Closest Approach is actually 12/12/2010. It still looks like it wont get within the distance of lunar orbit, presuming the graph in any way represents reality.

  9. His current prediction shows an unacceptable lack of fit to the current data, most of the current data is below the best fit line, although it is still within the 5% lower error bar.

  10. Vuk etc. says:
    October 6, 2010 at 9:09 am
    We ought to trust in that “double layer” EM shield called “atmosphere” (& all its “spheres”), where its effect usually called “friction” by some, will vaporize it.

  11. Predictions????? Hathaway is actually making adjustments as reality has caught up with his computer predictions. He should quit while he’s ahead.

  12. Whoever made that blink-comparator needs another cup of coffee or something. They need to re-scale the graphs to match each other before comparing them. They’re on different timescales, and the relevant sections for comparison don’t overlap properly.
    Hmmn, a misleading graph ginned up by someone overly keen to prove a point. There’s a certain irony there…

  13. Sean Houlihane says:
    Anyone claiming their early prediction is any better than a lucky guess needs to explain why their method was demonstrably better when they made their prediction.
    There are number of values, actual, smoothed, annual, (SSN, Rmax etc). I made my prediction in 2003 for actual peak number which you can see HERE ; it is 80, we have already seen actual count of 60+.
    Method of my prediction

  14. Jeremy writes “What were these “Halloween events” in 2003?”
    Some of the most active sunspots of this century occurred at the end of October 2003. Aircraft flew at lower altitudes, and various other precautions were taken.

  15. apparently the Sun flunked Statistics 101 … just because we can measure something doesn’t mean we can predict its future numbers … all we can see are the results (sunspots) of interactions inside the Sun that we have not the slightest idea about …

  16. @Vuk again.. (sorry for OT threadjackspam moderators.)
    Vuk, I apologize, closest approach is actually December 9th, at 0.0428 AU from Earth.
    http://www.flickr.com/photos/50716889@N00/5057653820/
    That is approximately 6,402,794.4 kilometers (or 3,978,511.99 miles), which is WELL outside of lunar orbit. Again presuming this graph in any way is close to reality, I think we’re ok.
    /end threadjack

  17. Well done to Dr Hathaway for updating and explaining the basis of his predictions, we will watch with interest. I check Geoff Sharp’s site regularly and find the discussions with Leif entertaining.
    Interesting times ahead.

  18. Jeremy says:
    ………..
    I just hope that the orbit prediction is far more accurate than one for the sunspot number.
    amicus curiae says:
    ……………..
    Asteroid encounter. (copy and paste entire line)

  19. Over a year and a half ago, I guessed SC#24 would peak at 80 around July 2013. At the time I made my guess, back in January 2009, Hathaway had revised his original guesses a couple times to lower and later. He has gone from 150/early 2012, to 134/early 2012, to 104/mid 2012. Now Hathaway’s guess is 64/July 2013.
    At least I had the courtesy to round my guess to a multiple of 10! Perhaps that is because I know I have no special expertise in this area, no models, and am not on the government payroll.
    For now, I’m sticking with my prediction of 80/July 2013. I’m hoping I’m high and Hathaway’s 64/July 2013 turns out to be the case. It would be better if the peak is even lower and later, because that could help reduce the warming trends and perhaps give us a bit of cooling.

  20. Mr Hathaway is a science man of integrity, I wish one could say the same about other scientists. Myself I am no climate nor solar scientist but I bet that a situation similar to the early 1800s will happen.
    The AGW Titanic is sinking as inexorably as the original Titanic sunk. The laws of physics are inexorable, period.

  21. Mr Hathaway is a science man of integrity, I wish one could say the same about some other scientists that we know. Myself I am no climate nor solar scientist but I bet that a situation similar to the early 1800s will happen.
    The AGW Titanic is sinking as inexorably as the original Titanic sunk. The laws of physics are inexorable.

  22. Hey, that’s funny. Back in 2007 I took part in a sweepstake for the next solar maximum. My guess was 65! So I’m hoping that Hathaway is right this time. Unfortunately he is usually wrong!

  23. Perhaps Goldman Sachs, Pachauri et al, could set up a sunspot number futures market? Those with particularly good models and conviction could then become wealthy, in a similar manner to those with models and conviction relating to CO2 levels. I am sure only a few laws would need to be changed.

  24. This is the 3rd? New prediction.
    Joseph D’Aleo had it right two years ago.
    50 to 60 in peak year. Total sunspot mean for cycle around 200.
    Unlike twin to follow.

  25. Jeremy says:
    October 6, 2010 at 9:32 am
    In layman’s terms:
    Asteroid: 2010 JL33
    Closest approach: Dec 9
    Miss distance: 16.6 Lunar Distances (1 LD = 384,401 km)
    Visual magnitude at closest approach: 17.6
    Asteroid size: 1.3 km
    …from spaceweather.com (last object in table)

  26. One might think that the solar guys have some integrity *at least in part* (I do not intend to neglect the inherent integrity of given individuals) because they deal in timeframes and observations that are verifiable/falsifiable in the mid-term. That tends to reenforce whatever natural integrity they have.

  27. Enneagram says:
    October 6, 2010 at 9:25 am
    We ought to trust in that “double layer” EM shield called “atmosphere” (& all its “spheres”), where its effect usually called “friction” by some, will vaporize it.
    It’s 1300 meters in diameter!

  28. Stephan,
    Its a scandal to equal climategate, they are disowning a record they created and defended and used to advise government, they are publicly funded and have pimped their construction as first rate when in fact they knew all along it was rubbish. The NZ government will be left swinging in the wind by this because their whole energy policy was based on the NIWA record.
    Governments do not like to be made to look stupid by underlings on the payroll and they do not on the whole enjoy taking flak, a big ooops.

  29. “Anything is possible says:
    October 6, 2010 at 8:59 am
    A maximum of 64 would make Solar Cycle 24 the quietest for nearly 200 years. It will be interesting to see what effect that will have on Global Temperatures……”
    Not quite. Solar Cycle 14 peaked at 64.2 in 1906.
    I’m still sticking to max of 50. Today the visible disk is blank but officially we have a sunspot number of 11… nothing has changed, the numbers will continue to be inflated.
    The Flux 10.7 is very interesting to watch… it has dipped back to near minimum levels (75) and has yet to reach 100!

  30. Predictions are only valid if derived from a statistically stable system, wherein all of the significant variables are known. As for the several billion year old Sun, I doubt we have a good handle on that. Wheels within wheels. We should be amused by our ignorance, yet we pronounce as if we are Lords of the Universe.

  31. Mr. Alex says:
    October 6, 2010 at 10:53 am
    I’m still sticking to max of 50.

    I’m right there with you, mine was homed in at an average of 47 or lower but 50’s close enough for a nice round number. ☺

  32. With all the solar research going on at NASA and this is the best that they can model on a relatively short term prediction? Kind of demonstrates how good models aren’t with a pointer aimed at all those AGW models.

  33. They are still increasing the base cycle to generate a higher peak. I wouldn’t increase the cycle length without further evidence. I expect we will peak Christmas 2012 at 50. (yeah, +/- 10 points and 6 months) But 2014 is too late for peak.

  34. In Webster’s under “clueless predictions” you’ll see NASA’s Hathaway. These guys have been wrong, wrong, wrong every step along the way since 2006…

  35. Dennis Wingo says:
    October 6, 2010 at 8:50 am
    Is Leif still holding to his 72 prediction? Leif has there been anything that indicates to you that you would reduce your own prediction number? Also, even Hathaway and others from the NASA team had previously predicted a very low cycle 25, is this still the case?
    Since my prediction is based on the polar fields prior to and at solar minimum, the prediction will not change once minimum is past. So 72 it is. There is one thing to take into account: the prediction is based on magnetic field and thus predicts magnetic field. There are various proxies for the solar magnetic field: sunspot number, number of active regions, F10.7 microwave flux, Heliospheric magnetic field, cosmic ray modulation, etc. If the relationships between the proxies and the magnetic field do not change, it matters not which one you predict as one can simply convert from one to the other. If Livingston and Penn are correct, it is possible that the visible sunspots no longer is a good proxy. If so, the prediction must be expressed in terms of other proxies. E.g. F10.7, where it would stand at ~125 sfu, or number of active regions [72/12=6].

  36. Hi doc. Nice to see you are not budging, only if proxies are right, naturally.
    Once I caught a fish alive,
    Then I let go again.
    Why did you let it go?
    Because it bit my proxy so.
    Which proxy did it bite?
    The one I thought it was right.

  37. Richard Altstatt says that 2014 is too late for predicted minimum (but anyway Hathaway predicts mid-2013). Well, though 4 years is a good average for min-to-max, weaker cycles tend to build more slowly, and it would only need to be 5.5 years to make it peak in mid-2014. That can’t be ruled out yet.
    Mr. Alex notes the spotless sun with a count of 11. In fact NOAA’s data for October 5th say SSN=11 but sunspot area = 0! How bizarre is that? Give me the Layman’s count any day, it’s far more likely to be like the way Wolf assessed things, which is rather important for comparative purposes dontchathink?
    Rich.

  38. @ Billy Liar says:
    October 6, 2010 at 10:42 am
    @ Enneagram says:
    October 6, 2010 at 9:25 am
    We ought to trust in that “double layer” EM shield called “atmosphere” (& all its “spheres”), where its effect usually called “friction” by some, will vaporize it.
    It’s 1300 meters in diameter!

    Plug in that dia. here, along with other parameters as indicated, to see what the estimated impact effects will be at a specific distance from ground zero. http://impact.ese.ic.ac.uk/ImpactEffects/
    It varies greatly depending on the composition of the body, etc. But it would be a significant hit in any case.

  39. Leif Svalgaard says:
    October 6, 2010 at 11:48 am
    If Livingston and Penn are correct, it is possible that the visible sunspots no longer is a good proxy.

    Has anyone come up with any theories on how Livingston and Penn might be correct?
    AFAIK, no one – not even – they have put forward any mechanism for their prediction.

  40. If my memory serves me well, Hathaway always said that his predictions were not well founded until 3 years after the following cycle had begun (minimum). Badly worded by me. So none of his “predictions” were anything more than approximations or guesses. What really anoyed me was when he kept saying that there was nothing unusual about what was happening when it was blatantly obvious that there was. Blind arrogance? In the past “the panels” predictions after the start of the cycle have been good within the calculated confidence limits. There were many predictions other than DrH’s which were patently absurd. So, Thanks DrH for your time and to Leif for his incredible patience over several years on this blog.

  41. Lockwood demonstrates link between low sun and low temps
    Posted on April 14, 2010 by Anthony Watts
    NOW,
    A stronger Sun actually cools the Earth,
    An increase in solar activity from the Sun actually cools the Earth, suggests new research that will renew the debate over the science behind climate change.
    Focused on a three-year snapshot of time between 2004 and 2007.
    As solar activity waned at the end of one of the Sun’s 11-year cycles, the new data shows the amount of light and heat reaching the Earth rose rather than fell. Its impact on melting polar ice caps, and drying up rivers could therefore have been exaggerated by conventional climate models during the period.
    http://www.telegraph.co.uk/earth/environment/climatechange/8046586/A-stronger-Sun-actually-cools-the-Earth.html

  42. Mr. Alex says:
    October 6, 2010 at 10:53 am
    “Anything is possible says:
    October 6, 2010 at 8:59 am
    A maximum of 64 would make Solar Cycle 24 the quietest for nearly 200 years. It will be interesting to see what effect that will have on Global Temperatures……”
    Not quite. Solar Cycle 14 peaked at 64.2 in 1906.
    Having watched this solar event for some years now I have little confidence that we can realistically compare current sunspot numbers with those counted back at the turn of the last century. Sadly.

  43. A stronger Sun actually cools the Earth
    Over the past century, overall solar activity has been increasing and should therefore cool the Earth, yet global temperatures have increased.
    There you have it, IT`S CO2.

  44. Re Hathaway.
    My prediction is a test of the polar field method. Hathaway’s has a different aim, namely to reflect operationally what the current [based on all data up to now] outlook is. So his prediction SHOULD change with time, just like a regular weather prediction for next week would change from day to day, getting better and better [we hope] the closer we get to next week,

  45. Leif Svalgaard says:
    just like a regular weather prediction for next week would change from day to day, getting better and better [we hope] the closer we get to next week,
    ======================================================
    Is this still called weekly prediction? 🙂

  46. See – owe to Rich says:
    October 6, 2010 at 12:19 pm
    In fact NOAA’s data for October 5th say SSN=11 but sunspot area = 0! How bizarre is that? Give me the Layman’s count any day, it’s far more likely to be like the way Wolf assessed things, which is rather important for comparative purposes dontchathink?
    NOAA reports area in increments of 10 millionth of the Hemisphere. If the area is less it is counted as zero. The sunspot was at the very limb and its projected area was too small to be counted [at the limb the area becomes zero].
    The Layman’s count is misconceived to ‘support’ the sunspot number around 1800-1820, before Wolf was even born. In the 150 years since Wolf we have learned how to count sunspots and what the count means. The Layman’s count is junk.

  47. Curiousgeorge says:
    ………….
    parameters:
    Distance from Impact: 1000 meters ( = 3280.00 feet )
    Projectile diameter: 1.30 km ( = 0.81 miles )
    Projectile Density: 1500 kg/m3
    Impact Velocity: 330.00 meters per second ( speed of a military jet )
    Impact Angle: 45 degrees
    Target Density: 2500 kg/m3, Target Type: Sedimentary Rock
    Results
    22.4 MegaTons TNT
    Transient Crater Diameter: 1.81 km ( = 1.13 miles )
    Transient Crater Depth: 641 meters ( = 2100 feet )
    Final Crater Diameter: 2.26 km ( = 1.41 miles )
    Final Crater Depth: 482 meters ( = 1580 feet )
    The crater formed is a simple crater
    -little vaporization occurs; no fireball is created, therefore, there is no thermal radiation damage.
    At distance from Impact: 1000 meters
    -The major seismic shaking will arrive approximately 200 milliseconds after impact.
    Richter Scale Magnitude: 5.5
    Air Blast:
    The air blast will arrive approximately 3.03 seconds after impact.
    Multistory wall-bearing buildings will collapse.
    Wood frame buildings will almost completely collapse.
    Multistory steel-framed office-type buildings will suffer extreme frame distortion, incipient collapse.
    Highway truss bridges will collapse.
    Highway girder bridges will collapse.
    Glass windows will shatter.
    Cars and trucks will be largely displaced and grossly distorted and will require rebuilding before use.
    Up to 90 percent of trees blown down; remainder stripped of branches and leaves.

  48. I’m sorry but this isn’t a prediction or forecast IMO, it’s another guess. And history has proved that his previous guesses were incorrect. So regardless of what the new and improved model forecasts we know for a fact that the model can’t be deemed to have any skill.

  49. Thanks, Leif, for reminding us of geometry (or heliometry we should say!). However, am I correct in thinking that there is a rule whereby spots are not to be counted if they are too close to the limb, and so if they’re not too close they should have some area? I expect you might know the details of that. Are you convinced that NOAA adhered to the (assumed) rule on October 5th? I looked at the solarcycle24.com image and I wouldn’t have counted a spot.
    Rich.

  50. See – owe to Rich says:
    October 6, 2010 at 2:20 pm
    there is a rule whereby spots are not to be counted if they are too close to the limb,
    No such rule
    that NOAA adhered to the (assumed) rule on October 5th? I looked at the solarcycle24.com image and I wouldn’t have counted a spot.
    What NOAA counted shows what they adhered to. There is also the issue when to count. The classical Wolf/Wolfer rule says to count only once, e.g. in the morning when seeing is usually the best. So the counts from NOAA and Brussels are sometimes different because of different times.
    The point is that there is nothing ‘bizarre’ or ‘conspiratorial’ or ‘nefarious’ in all of this. The observers do their best to deal subjectively with a messy phenomenon.

  51. Vuk etc says:
    October 6, 2010 at 1:27 pm

    parameters:
    Impact Velocity: 330.00 meters per second ( speed of a military jet )

    That’s got to be off by a couple orders of magnitude. Try escape velocity, which is 41% greater than Low Earth Orbit speed. Lessee, I can never remember those. 24,000 miles (40,000 Km) in 90 minutes (5400 seconds), is 7.4 Km/sec, times sqrt(2) is over 10 Km/sec.
    So 1.5 orders of magnitude. Kinetic energy about 1000X what that calculation came up with.
    I’ll rely on the estimated visual magnitude of 17 – that’s about as bright as Pluto, IIRC.
    Can we go back to sun spots?

  52. So now the establishment is finally starting to see that the sun is slumbering when will any of this affect government policy – as in the threat of a cooling world!

  53. Solar surprise for climate issueBy Richard Black
    Environment correspondent, BBC News
    “It is possible, contended Mike Lockwood of Reading University, that there was something special about the last solar cycle – that it could mark the end of an extended phase of relatively high output, and the transition into a less active phase.
    “If you look back… 9-10,000 years, you find oscillations of the Sun between ‘grand maxima’ and ‘grand minima’,” he said.
    “It’s now emerging that the ‘space age’ has been a grand maximum; so my view is that the Sun is due to fall out of this and into a ‘grand minimum’, so I would not be surprised if in 50 years’ time we find ourselves in conditions like the ‘Maunder Minimum’ [of the late 17th and early 18th Centuries] associated with the ‘Little Ice Age’.”

  54. So how long before the National Enquirer-type rags start screaming: “Sun to go SUPERNOVA in Dec. 2012!!!”
    😉

  55. In this forum, the word ‘prediction’ is being used the way the man in the street uses it. In that usage, the claim that the Jets will win by 35 on Sunday is a prediction. But that is not scientific prediction. In science, prediction and explanation go hand-in-hand and are symmetric. I can predict an event “A” only if I have physical hypotheses and some statement of initial conditions that imply the future occurrence of “A.” The hypotheses will describe the mechanism that brings about “A.” Explanation of event “A” is by reference to the hypotheses used to predict it. Also, hypotheses must be reasonably confirmed. Folks, what we are doing here is extrapolating from recent and not so recent graphs. Extrapolation should not be glorified with the name “scientific prediction.”

  56. Ric Werme
    Asteroid would be coming down through atmosphere and not being aerodynamically shaped, I thought I would downgrade its velocity to the lowest within reason, speed of sound. Kinetic energy increases with velocitys quared , hence I did not whish to be too cataclysmic.
    Ah., sunspots, whatever happened to those?
    If Dr.S’s hypothesis on polar fields is correct than next 20 years are going to be rather lacklustre.
    http://www.vukcevic.talktalk.net/LFC2.htm

  57. But we see these graphics all the time, and every one turns out not to be a prediction, but a historic update, in which we simply move the goal posts over. Hence it is really no more than an intelligent guess.
    Anyway, I’m off to study the chicken entrails, might get a better answer.

  58. I’m making a prediction that’s virtually a dead cinch: all the predictions will be appreciably WRONG.

  59. has someone a link to a blink image showing hathaway’s series of failed predictions? Whats he up to now? 10 fails in a row?

  60. Vuk, minimum impact speed for an asteroid is around 10 -11 km/s (1100 m/s).
    (also military jets hit 330 m/s when at or near Mach 1 at sea level. Usually they are flying at 200 to 550 mph most of the time. That’s about 90 m/s to about 250 m/s, depending on the mission profile and the where they are on it)

  61. this site: Mad Sci Network calculates the average speed for an asteroid at 47,000 mph. That’s really close to 21 km/s. So allowing for the velocity attenuation in the atmosphere, you are going to get the 11 km/s that I posted (or higher) depending on angle of entry.

  62. Vuk etc says:
    October 6, 2010 at 3:18 pm

    Asteroid would be coming down through atmosphere and not being aerodynamically shaped, I thought I would downgrade its velocity to the lowest within reason, speed of sound. Kinetic energy increases with velocity squared , hence I did not wish to be too cataclysmic.

    Given:
    Projectile diameter: 1.30 km ( = 0.81 miles )
    Projectile Density: 1500 kg/m3
    Assume a sphere (close enough) volume is 4/3 * pi * r^3
    4/3 * 3 * 650^3 = 1 million m^3, 1 Mm^3. Mass is 1.5 Tgrams (T for Tera, 10^12).
    Force averaged over the cross section of sphere is mg/(pi * r^2), where g is 9.8 newtons, call it 10.
    15 Tn/ 1.3 Mm^2 = 10 Mnewtons/meter^2. A newton is about 0.2 lb, a m^2 is about 10 ft^2, so to maintain the object’s speed, the atmosphere needs to push back with 200,000 lb/ft^2, 1,400 lb/in^2, or about 100 bar.
    So, if the asteroid compresses the air ahead of it by a factor of 100 (less since the air will heat up to well into incandesence), its acceleration will drop to zero just before impact. (Speed will still be 10 Km/sec.)
    Meteors are around altitude 60 Km, I think? You used an entry angle of 45°, so the trajectory will be 84 Km. At 10 Km/sec, that’s all of 8.4 seconds to slow down to.
    The Tunguska event was estimated to be an object a few tens of meters across, this object is 50X on a dimension, 125,000X the volume, hence mass, hence energy. Impact would be cataclysmic.

  63. rbateman says:
    October 6, 2010 at 9:22 pm
    Why even bother predicting: Just let the thing generate itself, since this is already SC24.
    As Hathaway points out the data is not homogeneous with time:
    “Careful inspection of the data indicates that quantities such as sunspot area are not uniform across datasets or even within a given dataset. For example, the ratio of the umbral areas (the darker part of the sunspot) to total spot area (including the lighter penumbra) changes abruptly in 1941/1942 and the ratio of the total sunspot area to the sunspot number changes dramatically with the start of the USAF/NOAA data. “

  64. Leif Svalgaard says
    October 6, 2010 at 1:24 pm

    NOAA reports area in increments of 10 millionth of the Hemisphere. If the area is less it is counted as zero. The sunspot was at the very limb and its projected area was too small to be counted [at the limb the area becomes zero].
    The Layman’s count is misconceived to ‘support’ the sunspot number around 1800-1820, before Wolf was even born. In the 150 years since Wolf we have learned how to count sunspots and what the count means. The Layman’s count is junk.

    —–
    There was (and still is) a problem with SWPC sunspot data for October 5. On one hand they report an SSN of 11, on the other hand their solar region summary (http://www.swpc.noaa.gov/ftpdir/forecasts/SRS/1006SRS.txt) states that there are no sunspots. Normally the SRS is the most reliable as that data is used as a basis for the SSN. I don’t know what happened in this case, perhaps the forecaster responsible for updating the SSN was given the wrong information. So based on the SRS SSN should have been zero. Another problem is that there were actually two active regions with tiny spots on October 5, both AR 11111 and an unnumbered region which was located at N21E01 by the end of the UTC day. The spots were visible in both SOHO and SDO images.
    Leif, I would have to agree that the Layman’s count is junk.

  65. Leif Svalgaard says:
    October 6, 2010 at 12:23 pm
    “I maintain a monthly ‘Active Region count’ which essentially is the number of active regions per day summed over a month.”
    In the top panel, the “humps” are becoming smaller with each cycle.
    Is there a link which sheds light on this?

  66. Brownedoff says:
    October 7, 2010 at 3:05 am
    In the top panel, the “humps” are becoming smaller with each cycle.
    Is there a link which sheds light on this?

    Yes, solar cycles have become smaller and smaller.
    You can find some discussion of that here: http://www.leif.org/research/Predicting%20the%20Solar%20Cycle%20(SORCE%202010).pdf
    The Sun’s polar fields are getting weaker, which might account for the decrease of active regions. See http://www.leif.org/research/Cycle%2024%20Smallest%20100%20years.pdf

  67. Peaks 22 and 23 look like bimodal peaks. If there are two slightly superimosed peaks, perhapst the cycle troughs are reinforced at some negative value.

Comments are closed.