Leif Svalgaard writes in with a collection of points on the 10.7 cm solar radio flux. Being busy tonight, I’m happy to oblige posting them. – Anthony
Leif writes:
People often call out that F10.7 flux has now reached a new low, and that a Grand minimum is imminent.
Perhaps this graph would calm nerves a bit:
The blue curve is the current F10.7 flux [adjusted to 1 AU, of course] and the red curve is F10.7 back at the 1954 minimum. The D spike (in 1954) was due to an old cycle [18] region.
There is always the problem of how to align two such curves.. These two were aligned by eye to convey the general nature of the flux over a minimum. The peaks labeled B and C and the low part A were arbitrarily aligned, because peaks often influence the flux for several weeks so would form natural points of correspondence. The detailed similarity is, of course, of no significance. Note, however that because of the 27-day recurrence one some peaks are aligned others will be too. again, this has no further [deeper] significance. The next solar cycle is predicted to be quite low and the cycle following the 1954 minimum was one of the largest recorded. We will, of course, with excitement watch how the blue curve will fare over the next year or so, to see how the ‘ramp up’ will compare to the steep ramp up in 1955-1956.
Of course, as there was more activity before and after the minimum and even during [as cycles overlap]. For the very year of the minimum apart from the spike at D there is very little difference. The important issue [for me] is the absolute level, because that is a measure of the density and temperature of the lower corona, generated by the ‘network’ or background magnetic field, which seems very constant from minimum to minimum, and certainly does not portend an imminent Grand Minimum, which is not to say that such could not come, just that a low F10.7 is not an indicator for it.
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Thank you Leif.
I could ride that 2008 roller-coaster with a full stomach and get away with it. Either that, or it’s the part where the ride ends… 8^)
As you pointed out the alignment was arbitrary. Had you aligned the peak of cycle 18 with the peak of cycle 23, the dramatic difference would have been apparent. For a point that absolute value of 10.7 is not significant, a time variance chart is inappropriate.
what about a low over an extended period 10.7 ?
the devil is in the details – and yes, the next 18 months will be of great interest.
other natural events may have masked the historical record for grand minimums, but perhaps someone could refresh my memory as to the periodicity of
such events ?
my bet is that it’s going to get cold for the next 20 – 30 years, just a question of how cold …
“certainly does not portend an imminent Grand Minimum, which is not to say that such could not come, just that a low F10.7 is not an indicator for it.”
That’s the thing I most admire about you Lief… that as a scientist you will defend things you know for certain and look skeptically at anything else that is uncertain. Would that more scientists embraced your careful methodology.
It would seem we haven’t gotten to the “up tick” yet. The proof is in the pudding, which would be an “up tick”…and if there isn’t an “up tick”?
Back to the drawing board…
well, by eye ball it looks like 6 more months to see if we ramp up or piddle out.
I say we continue on low for at least 3 more months.
tx leif
“Being busy tonight, I’m happy to oblige posting them (him?).”
And if you weren’t busy?
Leif: “does not portend an imminent Grand Minimum”
That’s a relief.
We may not have to wait that long (year or so). There is that arch that extended from low point A to low point D. From D to present is what may be the first half of another arch, which peaked at 2009.4. The most likely outcomes to me are a long gentle slope of a weak cycle.
A roll on down to another “D” point minimum completing the 2nd arch or…
following on up the steep slope of 1954-55 negating the arch.
Those would be the extreme conditions.
A true spectator sport.
Thanks, Leif.
Many thanks Leif. It appears that the 1954 data are at higher levels and fall to a minimm for a shorter time than the 2006 data. Is that right? Is that significant?
Keep up the good work!
Hugh
To me the blue curve still looks a heck of a lot flatter than the red one with nothing indicating a sharp rise ahead any time soon. The red curve looks like bowl, the blue one like a cookie sheet.
The absolute minimum may not be an indicator but the average level over time could be.
On that basis the blue line is a lot lower than the red line during the period displayed.
Leif Svalgaard, with respect the old data have a bell shape curve, the current
measurement is more or less flat. Please explain?
Mick.
PS: thanks for your education/contribution! :))
1990-2000-2010 Sunspot graph curve resembles more 1870-1880 look than anything else on record (followed by 1885 approx max of 75 to 80 approx) looking at all the cycles at http://science.msfc.nasa.gov/ssl/pad/solar/images/zurich.gif
…what do others think?
Leif, I check your website every morning. I noticed recently that you lowered the line (which I presume is hand drawn) that denotes (as I think you mean) the likely low extent of the 10.7. Not quite trending up as fast as previously thought?
Stephen Wilde (02:01:22) :
On that basis the blue line is a lot lower than the red line during the period displayed.
Mick (02:06:06) :
the old data have a bell shape curve, the current measurement is more or less flat. Please explain?
The red curve is higher at both ends than the blue, because cycles 18 and 19 were larger than cycle 23 and [likely] 24. The point of interest is that over the year of the minimum, the levels of the red and the blue are very much the same, even though the following cycles [19 and 24] look to be very different, so the minimum level of F10.7 is not a good predictor of the next cycle.
I was feeling happy because the southern hemisphere of the sun is finally showing some life so Im hopeful we wont have to freeze our behinds off. I am a bit worried about present levels of volcanic activity though.
Im not sure I see the usefulness of the chart though. I have seen someone on solarcycle.24 do the same thing with the sunspot records over the marauder min as well. Only time is going to give us the ultimate answer.
It’s just a bit of wiggle matching to help pass the time while we wait innit Leif? 😉
If you compressed the timescale on the current data would you get a curve that more closely matched the data around and including the 1954 minimum?
Leif,
That graph is the biggest pile of crap ever in the history of bad curve matching.
The two curves do not match at all in the early part of the curve and yet come together because both are bottoming out? Nonsense. That isn’t a theory worth the electrons that were sacrificed to transmit that graph from Anthony’s server to my PC
The only scientifically legitimate response to the strange non-appearance of solar cycle 24 is to say “we have no idea what is causing the hiatus nor do we know when the hiatus will end, but we do know that the hiatus is longer than any comparable minimum since radio measurements were first undertaken in the 1950s”.
The radio measurements show no recovery from the lows first recorded nearly two years ago. The Sun shows such evanescent sun “specks” that I question whether 18th and 19th century astronomers would have recorded many of them. Every solar model that predicted the beginning of the next solar cycle has been shown to be wrong by the behaviour of the Sun.
I’m sorry if Anthony is surprised by my outburst, but I call it like I see it.
Anne ( 23:37:08)
As you pointed out the alignment was arbitrary. Had you aligned the peak of cycle 18 with the peak of cycle 23, the dramatic difference would have been apparent. For a point that absolute value of 10.7 is not significant, a time variance chart is inappropriate.
———-
This would be a given considering Cycle 18 was stronger than Cycle 23 so the initial part of the descending phase would have looked different when looking at peak to peak. And the comparison in his graph must go back to 1951 so you do get an idea of the higher flux values prior to the minimum in 1954. So I do not think that Leif is misrepresenting what is going on. Not that you were implying this.
Thanks Leif, I love reading your contributions. I am eagerly awaiting the ramp up toward Cycle 24 peak. It seems clear to me that we’ve crept past the minimum, but its going to be a while before we’ll be able to accurately compare the uptick rate to other cycles.
That will be the next bit of slow-motion fun about this cycle transition. I never even knew I was interested in this stuff before, now I’m talking about it at the dinner table while my kids exchange worried glances. Oh look, the paint is a bit less glossy this month! Has it finally turned the corner? 🙂 Fascinating stuff.
Dr. Svalgaard
When I mach my polar fields equation
http://www.geocities.com/vukcevicu/PolarField1.gif
to the actual measurements for a period extending to 30 years, you kindly describe it as ‘GARBAGE’.
May I return compliment in regards to the chart above.
John A
No need to be reticent about this, tell us what you think 🙂
My query is whether there is a clear and unambiguous match betwen lack of solar activity (no sunspots or lack of electro magnetic activity or any other criteria you want to use) and the climate here on earth-most notably in this context- some sort of prolonged cooling period.
tonyb
Leif.
1.I did an ‘envelope back’ calculation of the flux 10.7cm from a black body at 1 au
distance,radius 6.96e8 m , temperature 5780K.
I obtained 9.3e-22W/m2*Hz instead of 65e-22.
Is the corona much hotter than 5780K?
Is the corona radius much larger than 6.96e8 m?
Is my physics/mathematics poor?
2.Can you ,please,make some light in this paradox : how can the radiation 10.7 jump THREE times during the solar maximum,when the rest of the light emission is ~constant.
[snip – that was stupid and insulting to Dr. Svalgaard]