Leif Svalgaard writes: “Several people asked why I said that the SWPC F10.7 graph was ‘just wrong’. And I promised a follow up on that. Here it is.”
Happy to oblige! For reference, here is the original graph from SWPC. – Anthony
The SWPC F10.7 Radio Flux Prediction Graph
Leif Svalgaard, May 2009
Fitting the monthly average the F10.7 flux (reduced to 1 AU) against the International Sunspot number, R, for the entire interval 1951-2009 to a forth order polynomial gives a formula for computing the Flux from the sunspot:
Flux = 67.29 + 0.316 R + 0.01084 R 2 – 0.006813 R 3 + 0.0000001314 R 4 (1)
The correlation is shown in Figure 1 below:
We know that this formula does not accurately portray the most recent relationship between R and F10.7 (see previous essay), but if we make no assumptions or corrections and just take the data as they are we can consider the conversion formula as indicative of the average conditions the last half century.
SWPC gives a table showing the predicted sunspot Number and the predicted F10.7 cm flux for the next decade. Here are the first few rows of that table, with the middle value of the predicted values in bold script, followed by a high and low limit:
Year Month Predicted Sunspot Number Predicted F10.7 cm Flux:
2009 01 2.1 5.1 0.0 67.4 69.4 65.4 2009 02 2.7 7.7 0.0 67.3 70.3 64.3 2009 03 3.3 8.3 0.0 67.2 71.2 63.2 2009 04 3.9 9.9 0.0 67.2 71.2 63.2 2009 05 4.6 11.6 0.0 67.3 72.3 62.3 2009 06 5.5 12.5 0.0 67.5 73.5 61.5 2009 07 6.7 14.7 0.0 67.8 74.8 60.8 2009 08 8.1 17.1 0.0 68.2 76.2 60.2 2009 09 9.7 18.7 0.7 68.8 76.8 60.8 2009 10 11.5 21.5 1.5 69.7 78.7 60.7 2009 11 12.6 22.6 2.6 70.2 79.2 61.2 2009 12 14.6 24.6 4.6 72.1 81.1 63.1
Using this table we can plot the predicted Flux as shown by the smooth red curve for the next solar cycle [or alt least up through 2015, Figure 2]:
I don’t know how SWPC came by their predicted F10.7, but my best guess is that they ran a correlation like the one shown in Figure 1 and applied it to the predicted sunspot number. Doing this using the observed sunspot number up to last month gives the ragged blue curve with the smooth blue curve coming from the predicted sunspot number. There is a good match for the predicted part of the curves [the red and the blue after May 2009]. The graph on SWPC’s website http://www.swpc.noaa.gov/SolarCycle/ seems to match the smooth curves quite well, with the exception of the variation during 2009, which I show as the purple curve. It is simply incorrect to start the curve from a flux of 60 and inexplicable [to my way of thinking – other than plain sloppiness] why the graph should disagree with the published table at http://www.swpc.noaa.gov/ftpdir/weekly/Predict.txt
As discussed in the previous essay and obvious from the discrepancy between the red and blue ragged curves above in Figure 2, the formula (1) for the average correlation between the Flux and the Sunspot Number does not work so well after about 1989, so it is not clear that it should work after May 2009. This means that we have little idea about what the predicted F10.7 flux should be. If the Sunspot Number prediction is correct, then the F10.7 flux is predicted too high, and if the F10.7 flux prediction is correct, then the predicted Sunspot Number is too high. My own feeling is that since the predicted Sunspot Number is really a prediction of the number of active [magnetic] regions which should be reflected in the F10.7 Flux, that the Sunspot Number [based on visible spots] will be much smaller than the predicted values. This will, indeed, be interesting to watch. Either way, we’ll learn a lot.
road trip planner (03:17:06) :
May be a dumb question – but how do we have 1000 year record of solar activity?
Not at all. According to this hieroglyph even ancient Egyptians were into Sunspot numbers. Note a pock-marked Sun. Was the Sphinx holding peace of a coloured glass (known about since Phoenician times 1600 BC), and taking notes on the clay tablets. You may not instantly agree, but a glass of good vine might help.
http://www.uned.es/geo-1-historia-antigua-universal/EGIPTO%20RELIGION/akh_worship_a_page2-1_05.jpg
look s to be a factor of 0.01925 per day if 7.000% is correct .
A suggestion… according to you, and Livingston & Penn, sunspots are decreasing anamalously versus 10.7 cm flux. Have you considered changing your SC24 prediction from sunspot counts to 10.7 cm flux values? This would give an apples-to-apples comparison with past cycles.
Correction-
Should be: piece and wine.
Must stop using auto spell correction.
I understand overestimation of temperatures to support AGW, but why inflate the sunspot number?
Given the state of electronics in 1947, let alone 1937, I doubt that there was a whole lot of 10.7 cm solar emissions being regularly monitored back then; possibly detected; but I doubt there was significant measurment capability at nearly 3GHz.
And yes I was there; so I oughta know.
George
Leon Brozyna (10:25:01) :
what gives us the 3.5% adjustment at apogee & perigee? Upon what is the figure based? Is there a chart or a formula to determine each date’s adjustments for when we’re not at apogee or perigee?
The Earth’s orbit is an ellipse with a the largest difference 1/60 times larger than average and the smallest distance 1/60 times smaller than average, for a total of 1/60 +1/60 = 1/30. Because the flux falls off with the square of the distance, the flux difference is twice the distance difference, or 1/15 or the 7% total. A simple sine wave with maximum on January 4th and minimum on July 4th is a good fit to the every day distance.
Fluffy Clouds (Tim L) (12:39:30) :
can you give us an approximation based on the F10.7 flux prediction, what then the max Sunspot Number prediction would be?
No one will hold you to it lol.
Based on the polar fields and the ‘standard’ sunspot number the predicted SSN max is 70 [as of today]. If L&P are correct, no one knows. But what I predict is not really sunspots, but magnetic regions and they may still be there, a total of 7 per day at maximum. You get this number by dividing the SSN by 12.
George E. Smith (14:48:54) :
Given the state of electronics in 1947, let alone 1937, I doubt that there was a whole lot of 10.7 cm solar emissions being regularly monitored back then
Arthur Covington succeeded in monitoring the 10.7 cm flux from April 1947 on.
Carsten Arnholm, Norway (12:31:03) :
I don’t think they were actually looking for them per se, but were looking for transits of the moon, Mercury, Venus, etc. in the early times.
This site has current sightings: http://www.vds-sonne.de/gem/res/results.html
The last one was late March 2008 : http://www.vds-sonne.de/gem/res/anetz/J2008.html
The very biggest naked-eye spots (from my readings IMHO) occur just as the cycle nears end. The ones where you cannot help but notice, the monster spots. Something about the 2 hemisphere’s magnetics or spots coalescing.
So, can we get an hour’s worth of “Solar Science 202” credit for attending Lief’s classes regularly, and apply that to our required professional training hours for the year?
More importantly, can HE get 1200 students’ worth of tuition fees for THEIR attendance of HIS on-line lectures for “Solar Science 202” ? 8<)
—
To those who question whether the "eyeball only" observations in the Middle Ages would skip or miss small spots, I would point out that – as the months went by with fewer and spots, with longer intervals between spots that had previously (hundreds of years!) been regularly occurring – the observors would be both looking intensely FOR small spots, and would be more and more attracted to record even hints of spots. Over the years through the Minimum, absence of the their goal (seeing and counting spots) would mean even closer scrutiny of the sun every day that clouds did not cover its surface.
Also, closer attention to the sun through the minimum (as the absence continued) would mean that more observers over different areas of the Continent would be looking up every day – so even if several observers were covered by clouds, somebody else would be more likely to be looking up that day and could verify that no spots were visible.
—
But I do wish Hathaway would show not only his latest (very misleading!) prediction curve for SC24 and SC25, but each of his previous (very wrong!) predictions as well.
1705842 -42 MAY 5 / JUN 3 (YUNG-KUANG/1/4/-) CHINA
“THE SUN WAS WHITISH BLUE IN COLOR AND CAST NO SHADOWS. RIGHT AT ITS
CENTRE, THERE WERE FREQUENTLY SHADOWS AND NO BRILLIANCE. THAT SUMMER
WAS COLD UNTIL THE 9TH MONTH, WHEN THE SUN REGAINED ITS BRILLIANCE”.
[“HAN SHU”; YAU & STEPHENSON (1988)/2]
Now that’s what I call a highly unusual observation.
I haven’t yet finished reading through them all for color color changes, but a reddish sun is the normal color change reported.
By the mid 1930’s both the Marconi and EMI companies had receivers capable of working in these bands, as did their German rivals, the problem was transmitting pulses of sufficient energy to be useful. Hence the blocking oscillator and the dual beam tetrode and all that: until the cavity magnetron of course.
Which suggests they could have easily detected and measured on 10.7 if they had wanted to and if they had known what the noise was that they noticed and thus, as it were, why they might want to. One assumes that they simply regarded the noise as a nuisance rather than a possibly useful scientific observation: although I may do them an injustice.
As to the Maunder minimum far from becoming ever more eager to spot sunspots their absence increasingly led to the sceptical idea amongst the new generation of astronomers that they did not really exist at all: so that the later generation which grew up when they were exceedingly rare far from keenly searching for them tended to regard them, no pun intended, as almost if not quite mythical, and an eccentric obsession of their forebears. Only when they reappeared in quantity, as it were, did they reluctantly decide they were real after all.
Kindest Regards
Robert A Cook PE (18:00:30) :
“So, can we get an hour’s worth of “Solar Science 202″ credit. . .”
I’ve been lurking in the back of the classroom switching back and forth between links, searches, charts – and trying to do everything else I need to do. Scrambling to keep up, describes it well. Enjoying it all. Thanks to Leif and all the rest of you. John
As to interest and coverage prior and during the Maunder:
From ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/GROUP_SUNSPOT_NUMBERS/list1.dat
1642 1684 4186 HEVELIUS, J., DANZIG
and in this list : ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/GROUP_SUNSPOT_NUMBERS/alldata
Hevelius observed sunspot groups from 1642 to 1684, a total of 42 years, starting before the onset of the Maunder.
Likewise, 1660 1682 3697 PICARD, J., PARIS put in 22 years followed by
1682 1718 7170 LA HIRE, PH., PARIS
At this link:
ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SUNSPOT_NUMBERS/GROUP_SUNSPOT_NUMBERS/invent.dat
One can see who was keeping the sun under constant surveillance in what year.
There were enough dedicated observers.
Robert A Cook PE (18:00:30) :
More importantly, can HE get 1200 students’ worth of tuition fees for THEIR attendance of HIS on-line lectures for “Solar Science 202″ ? 8<)
There is always that shameless “donate” button… on my website…
rbateman (21:43:15) :
One can see who was keeping the sun under constant surveillance in what year….There were enough dedicated observers.
But one has to be a bit suspicious of claims that they observed every single day for years on end. The weather in Northern Europe is simply no good enough for that [not even California]. Here are the claimed days of observations for Hevelius:
1648 366 HEVELIUS, J., DANZIG
1649 365 HEVELIUS, J., DANZIG
1650 365 HEVELIUS, J., DANZIG
1651 365 HEVELIUS, J., DANZIG
Even Ken Schatten agrees with me that these numbers are inflated. One way of getting a perfect record of 365 days is for the observer to note: “last year I didn’t see a single spot”. Hoyt interpreted that [wrongly] as 365 days of clear weather with observation on every single day, even the Sabbath…
One always has to be a bit suspicious.
Hevelius did fall off in his later years, therefore we have to rely on others to fill in the gaps.
It would take several dedicated observers in Europe to get good coverage.
We need more digitization of existing drawings from the period, and since this is really an important time, all the more reason.
(The curiosity is killing me !).
btw…I tried the shameless donate button too, but it didn’t work for me, so off it went to the trash bin. An entrepenuer I am not.
The luck of the Irish.
” Leif Svalgaard (05:07:49) :
I said that “claim that cosmic rays influence the albedo [although observations show otherwise],” that is the albedo not the clouds. Presumably the albedo is the measure of how much of TSI gets absorbed by the surface. The albedo is measured by observing Earthshine on the Moon. Here is a graph [Palle et al.] of the albedo the past two solar cycles: http://www.leif.org/research/albedo.png It is clear that there is no solar cycle signal in that data.”
I wouldnt say that, sc 22 ended in 1996-97, and if you add in the Palle data since 2000, it is clear that the albedo is following the 22 year magnetic solar cycle.
So, yesterday SC24.com said that sunspot 1007 has faded and today (20/05) it is written:
“Sunspot 1007 has faded and is now simply a magnetic plage region once again. It did fetch a sunspot number of 11 however.”
How is that possible? A classic plage has no spots!
On the SC24 discussion board, someone asked:
“Isvalgaard I’m going to beat this DEAD HORSE one last time. Would a spot like 1017 have been counted during the cycle 23 peak ( and given a count of 18) yes/no.
Leif replied:
“Yes, but probably not during the 13 cycle peak, and VERY CERTAINLY not any before before 1893, because Rudolf Wolf [the inventor of the sunspot number] explicitly said NOT to count little specks and pores. His assistant, Alfred Wolfer, disagreed, so when Wolf died in 1893, guess what: the counting of specs began. Wolfer tried to put the [now larger] count back on the Wolf scale by multiplying the count by 0.6”
Did Rudolf Wolf request this at solar minimum too?
rbateman (21:43:15) :
One can see who was keeping the sun under constant surveillance in what year….There were enough dedicated observers.
Here is number of the observation days recorded by Paris Observatory in each month for years 1666-1668.
Note: an unusually low numbers in 1666. 1668 and the following years appear to be close to what could be expected.
1666:1,0,1,1,4,4,0,2,3,12,13,9
1667:8,11,8,5,14,8,15,18,12,5
1668:6,8,11,11,13,16,12,14,15,11,10,10
rbateman (21:43:15) :
One can see who was keeping the sun under constant surveillance in what year….There were enough dedicated observers.
Here is number of the observation days recorded by Paris Observatory in each month for years 1666-1668.
Note: an unusually low numbers in 1666. 1668 and the following years appear to be close to what could be expected.
1666:1,0,1,1,4,4,0,2,3,12,13,9
1667:9,8,11,8,5,14,8,15,18,9,12,5
1668:6,8,11,11,13,16,12,14,15,11,10,10
Mike Lorrey (23:24:03) :
I wouldnt say that, sc 22 ended in 1996-97, and if you add in the Palle data since 2000, it is clear that the albedo is following the 22 year magnetic solar cycle.
Except that the cosmic rays follow the 11-year cycle and the albedo should follow the same 11-year cycle if the variation of cosmic rays is the reason for the changing albedo [and hence temperature].
Alex (23:28:18) :
Did Rudolf Wolf request this at solar minimum too?
At all times.
Could it be one reason, if not the reason? Or even the primary reason?
Jeff Alberts (08:13:42) :
Could it be one reason, if not the reason? Or even the primary reason?
Either you have a definite theory, or you are just fishing around.
The counting of sunspots has increased over time because of technology. If you have attempted to project them with modest equipment (like Wolf used), then you would know how tenuous the tiny spots really are.
So, there are really two issues at play inflating the value of observed sunspots:
1.) detection of miniscule areas (nearing pores in size)
2.) detection of nebulous spots
Solution: Multiply hemispherical area x contrast AND set a value where photographic spots = projected spots.
i.e. = in the future when we can detect sunspots down to .001 in value, it will still be .001 of a spot.