I had written back in July 2008 about the 10.7cm solar radio flux hitting a new record low value. Part of that has to do with the inverse square law and the distance of the earth to the sun, which is at a maximum at the summer solstice. As you can see below there has been a very gradual rise since then as we approached the winter solstice. David Archibald provides an update below and compares our current period to other solar cycles. – Anthony
UPDATE: In comments, Leif Svalgaard offers his graph, and also speaks of the flatlining. See below the “read more” – Anthony
The graph above is of two year windows of the F 10.7 radio flux centered on the last five solar minima. They are stacked up so that they are 20 solar flux units apart on the same vertical scale. The original data is from: http://www.ngdc.noaa.gov/stp/SOLAR/ftpsolarradio.html#qbsa
That site notes:
“The quiet sun level is the flux density which would be observed in the absence of activity. Extrapolation to zero of plots of the 10.7cm flux against other activity indices such as plage area or total photospheric magnetic flux in active regions suggest a quiet sun flux density of about 64 s.f.u. This is rarely attained.” The lowest daily value in this minimum to date was 64.5 in June 2008.
What is evident is that this minimum is quite different from the previous four in that the intra-monthly amplitude has died from June 2008. The monthly average low was July 2008 and the series has been in uptrend at 0.7 units/month thereafter. This is a very weak but very consistent uptrend, perhaps the first sign of a rising Solar Cycle 24. There is very little noise in this signal, suggesting a very weak Solar Cycle 24.
– David Archibald
UPDATE: Leif Svalgaard writes in comments:
As part of my ‘homework’ for the Sunspot Panel [2 years ago] I produced a short document
http://www.leif.org/research/When%20is%20Minimum.pdf
comparing F10.7 and MgII [another solar index] around minima. I have updated the graph in the document to show the flat-lining of F10.7.
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A really simple question. Can you tell N from S in a sunspot just using your eyeballs or does it require instruments – other than telescopes?
REPLY: The SOHO magnetogram is helpful in this: http://sohowww.nascom.nasa.gov/data/realtime/mdi_mag/512/
papertiger (11:34:29) :
Don’t you mean, “for a minimum in Aug – Sep, 2008, we should see the GCR flux plateau about now”?
plateau if SC24 stays DOA or decrease as SC24 starts up. Since SC24 has started [albeit smallish] the effects of SC24 are on their way out through the heliosphere and we should see a decrease from now on, which may already have started.
Just want truth… (11:35:49) :
Could I have links/ names of all these? I’d like to read up on what they said.
You can have the name and link of the most important one, namely me: http://www.leif.org/research/Cycle%2024%20Smallest%20100%20years.pdf
Here are a lot more here: http://users.telenet.be/j.janssens/SC24.html
Leif, good evening. Could you tell me what flux is please?
REPLY: Oh come on, you can use the Internet right? And if you Google search for “flux” here’s one answer:
http://en.wikipedia.org/wiki/Flux
so 10.7 cm radio flux is….?
– Anthony
Sorry. I’m using my mobile both computers down. Its a bit hit and miss.
REPLY: Ah OK sorry then. I had no idea people read this blog on mobile devices. – Anthony
Leif:
I have been following this climate debate for years as an interested, but amateur, observer and I would like to thank you, because your comments and contributions have been among the most helpful in aiding me to come to some sort of understanding of these complex issues. My problem is that, while I have been able to increase my knowledge of the issues, the aquisition of that knowledge has been highly piecemeal, driven by the flow of topics on sites like this one. I’m hoping you could recommend a source for a good overview of the current state of solar science. I can tolerate a fair level of technical detail, so it needn’t be aimed at a man on the street level. I want to thank you again for your efforts because I feel if many more of those who nowadays call themselves scientists would follow your example human knowledge would be all the better for it.
Carsten Arnholm, Norway (12:43:23) :
This of course depends on availability of sufficient quality data for those old cycles. If it does not exist I think the minimum is anyone’s guess (I have my own).
First, the data I used doesn’t exist for earlier cycles.
Second, and more importantly, The frame of mind of most people [and of the panel] is/was colored by the recent cycles, and the whole [sneaky] point of the homework was to point out that if SC23 was like those, it should follow the red average curve, so if it in the time since 2007 began to deviate from that, we [the panel] would get a hint that perhaps things were different now. The panel at that time [and certainly before] were leaning towards a very large cycle and I was trying to make a case for a small cycle, by pointing out that should in the months to come [after March 2007] F10.7 fall below the red curve, perhaps SC24 would be small.
Hugo M (12:46:20) :
3) what is a sunspot? [yes, we don’t know!]
I learnt some time ago, looking onto a sunspot would be the equivalent of looking onto a cross section of a MHD flux tube?
You are substituting one word with another [much more fancy one], but that doesn’t solve anything. How and where does such a tube form? how does it hold together? how deep is it? Is it one tube or a bundle of very many small tubes? etc.
Wouldn’t miss it for the world. It makes my life sunnier.
Edward Morgan (13:43:41) :
Sorry. I’m using my mobile both computers down. Its a bit hit and miss.
If you shine a flashlight onto a wall, you see a bright spot. The spot is formed by a flux [or a stream] of photons coming out of the flashlight. The 10.7 solar radio flux is similarly a stream of photons coming out of the Sun [in all directions, some of it our way], but with a wavelength of 10.7 cm requiring a radio telescope to see it. The energy of that radio flux is very, very, very, very small. The energy of all the radio waves picked up by all radio telescopes at all times since such telescopes were invented is all together less that the kinetic energy of a single snow flake falling to the ground. The 10.7 cm radio flux is measured in ‘flux units’ [right now we get 68 of those]. One flux unit is 0.000,000,000,000,000,000,000,1 W/m2 per Hertz.
“…There I go, measuring my life in sunspot cycles again!…”
LOL
I hope nobody here does that!
Dave Wendt (13:45:03) :
I’m hoping you could recommend a source for a good overview of the current state of solar science.
http://www.amazon.com/Solar-Astrophysics-Peter-Foukal/dp/0471839353 second edition is one of the best
Dave Wendt (13:45:03) :
I’m hoping you could recommend a source for a good https://www.booksonboard.com/index.php?BODY=viewbook&BOOK=333700&v=synopsis
is the second revision. Get this one.
It is also in a paper version. Hunt for it.
What generates the 10.7 cm freq. band? H? He? A combination of factors? If this is a repeat, please excuse me. I cannot find the answer, and I never got far enough in Astronomy to know.
Perhaps you might explain for a non-scientist. I saw a previous post referring to ham radio operators needing solar activity for effective radio wave “propagation”.
Thanks.
The solstices have nothing to do with the Earth-Sun distance. Closest approach is on January 4, furthest approach is Jul 4 this year (see here) which a function of the elliptic nature of the orbit. The summer solstice is a function instead the orientation of the tilt of the Earth with respect to the Sun.
Leif, Thank-you very much for your answer.
For all I know, Leif, many astrophysicists were very pleased to be able to test parts of Einstein’s theories, and to prove them out.
“Extrapolation to zero of plots of the 10.7cm flux against other activity indices such as plage area or total photospheric magnetic flux in active regions suggest a quiet sun flux density of about 64 s.f.u. This is rarely attained.” The lowest daily value in this minimum to date was 64.5 in June 2008.”
Why would seeing more of the baseline proven out make me “one of those people”?
I have a suspicious mind , for one.
I would like to think that I will live long enough to see more reasonable assumptions about the sun proven or disproven.
In the meantime, I do not trust SC24 any faster than it unveils itself.
Leif Svalgaard @ur momisugly 11:21:06
Your list of known unkowns pretty much says we know diddly-squat 🙂
BTW For those here who decry oil-company financing, or political government funding of science, may I suggest you donate a small sum to both Leif’s web site and WUWT’s. If we all just gave a few dollars every , oh, say, 6 months, these guys would be independent scientists, a la 19 century. Several thousand widow mites make mighty independent scientists.
hunter (14:22:37) :
What generates the 10.7 cm freq. band? H? He? A combination of factors? If this is a repeat, please excuse me. I cannot find the answer, and I never got far enough in Astronomy to know.
A good source is
http://web.njit.edu/~gary/728/Lecture10.html
and all the other lectures, you get by putting ‘1’ ‘2’ ‘3’ etc in the above URL in place of the ’10’. In short, when an electron moves around and it sees a proton somewhere, that proton will deflect the path of the electron. When moving charges change direction they emit electromagnetic radiation.
bill p (14:29:32) :
“Does the Solar Flux affects the Earth?” No
It is not the radio flux, but most things that happen on the Sun [a big flare] results in radio waves also being generated, so the radio flux is a ‘proxy’ for solar activity as such [and that activity has an influence]. If you are sick and have a fever, you measure the fever with a thermometer. It is not the thermometer that made you sick.
The F 10.7 radio flux is important. People who get paid to predict solar activity for a living, such as Dr Schatten, quote their 10.7 flux number first and sunspot number second. It is what causes the exosphere to expand during the solar cycle creating drag on satellites. From this document: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20050244826_2005246339.pdf
“The reduced levels of solar activity would have concomitant effects upon the space environment in which satellites orbit. In particular, the largest influences would affect orbit determination of satellites in LEO (Low Earth Orbit), based upon the altered thermospheric and exospheric densities. A decrease in solar activity would result in smaller satellite decay rates, as well as fewer large solar events that can destroy satellite electronic functions. Other effects of reduced solar activity upon the space environment include enhanced galactic cosmic rays and more space debris at low altitudes (fkom the decay of old satellite parts, etc.). The reasons are well known: namely, solar activity serves to sweep the inner heliosphere of galactic cosmic rays, and lower exospheric densities result in decreased drag on LEO debris, allowing longer lifetimes.”
This is the reason why I think NASA was so irresponsible in promoting Dikpati’s forecast so heavily. The satellite launchers would be gearing up to spend billions on extra launches to compensate for shorter satellite lives, while ignoring Dr Schatten’s good track record. Or perhaps the commercial satellite launchers would have ignored Dikpati and only the internal NASA schedulers would have had to follow the party line.
The reason why I constructed the graph that way was to show the change in character. The noise has gone out of the system and it is now dead flat. In the 60 odd years of data, we haven’t seen anything like this before. It is a very interesting development.
On the subject of NASA, we haven’t heard from the Solar Cycle 24 Prediction Panel for a while. In one of their past announcements, they mentioned that solar minimum wasn’t here yet because: “the configuration of the large scale white-light corona has not yet relaxed to a simple dipole; the heliospheric current sheet has not yet flattened”.
As a member of that panel, could Dr Svalgaard enlighten us with respect to the current status of the large scale white-light corona and the heliospheric current sheet?
C mitchell (13:02:41) :
“Would some one please explain this in lay man terms, so that we who are lacking in scientific knowledge can understand this?” I’m with C – as I’ve said before, I ride the short bus to WUWT.
The following three posts are somewhat instructive to me:
1) Leif Svalgaard (09:31:51) :
“the_Butcher (08:39:01) :
‘Does the Solar Flux affects the Earth?’
No”
2) kuhnkat (10:10:17) :
“the_Butcher,
‘the Solar Flux, represented by the 10.7cm wavelength, is a PROXY for the overall output of the sun that DOES affect the earth. Leif is correct of course, BUT, what it represents is a lower radiance on the earth that DOES affect us. How much effect for the recorded change is under heated debate even without including hypothesized indirect influences.'”
3) Leif Svalgaard (14:08:50) : [will not quote]
From these posts, I’m guessing that the Solar Flux at 10.7cm is a measure of a certain, specific output of energy [using this term very unscientifically – now stop snorting about that being obvious] radiated from the sun to the earth, which can be /is [?] representative of all/some [?] energy radiated from the sun to the earth. In turn, the effect of the energy represented by the Solar Flux at 10.7cm on the earth’s climate is being “hotly debated.” Is this somewhat correct?
The 10.7cm solar flux has no significant impact on the Earth; it causes some small degree of RF heating in the atmosphere, I suppose, but that’s inconsequential compared to heating due to insolation from visible and IR light. The 10.7cm solar flux number is, however, believed to be correlated with solar X-ray emission levels; high X-ray emission levels (which are associated with high sunspot activity levels) increase ionization of the upper atmosphere, and it is this that affects radio frequency propagation. (Radio activity is also affected by CMEs.)
It’s the X-rays that radio operators care about; the only thing the 10.7 cm flux does is make 2800 MHz useless for radio communications because of all the noise generated by the sun on that frequency.
very interesting…i wonder how long this will have to go on before the “scientists” acknowledge something unique is happening….
David Archibald (15:27:10) :
The F 10.7 radio flux is important. […] It is what causes the exosphere to expand during the solar cycle creating drag on satellites.
No, this is highly incorrect. The F10.7 radio flux is important because it is a proxy for what causes the exosphere to expand, namely the extreme UV and X-ray emission plus Joule-heating from geomagnetic activity. The radio flux per se has no effect.
This is the reason why I think NASA was so irresponsible in promoting Dikpati’s forecast so heavily.
NASA likes ‘breakthroughs’. Real or imagined.
On the subject of NASA, we haven’t heard from the Solar Cycle 24 Prediction Panel for a while.
And you won’t because, there will be no more meetings as we didn’t produce the desired [high] consensus so NASA/NOAA has lost interest.
As a member of that panel, could Dr Svalgaard enlighten us with respect to the current status of the large scale white-light corona and the heliospheric current sheet?
As you can see here http://sohowww.nascom.nasa.gov/data/realtime/c2/512/ the corona is pretty flat [albeit a bit crooked] and more importantly the HCS is now so flat that the Rosenberg-Coleman effect has become visible [this effect is a better indicator of the flatness than the computed ’tilt angle’ – the latter relying on over-simplified physics rather than observation]. For more on this effect see http://www.leif.org/research/Asymmetric%20Rosenberg-Coleman%20Effect.pdf and http://www.leif.org/research/Semiannual%20Variation%201954%20and%201996.pdf and http://www.leif.org/research/Anomalous%20Cosmic-Ray%20Anisotropy,%201954.pdf and http://www.leif.org/research/A%20View%20of%20Solar%20Magnetic%20Fields,%20the%20Solar%20Corona,%20and%20the%20Solar%20Wind%20in%20Three%20Dimensions.pdf and http://www.leif.org/research/suipr699.pdf [page 51 ff]
so the minimum is upon us, or probably even past as the Rosenberg-Coleman effect is strongest during the rising part of the cycle: http://www.leif.org/research/Asymmetric%20Rosenberg-Coleman%20Effect.pdf
Walter Cronanty (15:49:19) :
Is this somewhat correct?
Spot on [pun intended]
Anthony minor point of clarification required in your intro:
Aphelion: the point on its orbit when the Earth is farthest from the sun (~4th July), and
Perihelion: the point on its orbit when the Earth is closest to the sun (~4th January).
Very close to solstice(s) dates anyway.
REPLY: That is what I meant, but I just didn’t express it well. Thanks for the clarifications. – Anthony