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theartist

F10.7cm Solar Minimum Analysis

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Source of Raw Data for the following graphs. [Clicking on the graphs may provide a sharper image.]

2067372225_F10.7SC2324smoothed.thumb.png.bc62ba14c0f0969238e8cda48699e0f5.png1117061032_F10.7SC2425smoothedadjcorrection.thumb.png.bcb0061a274a124d38b5f1126cc1797e.png

If the adjusted_flux goes below the 'line of lows' after the Crossover (to occur on ~10/1/2019), then the 'Bremen Metric' will most likely be violated.  Conversely, if the adjusted_flux does not go below the 'line of lows' by mid-November, then the 'Bremen Metric' will most likely be confirmed.  (Note, the 'Bremen Metric' is discussed in this thread and this thread.)

 

Edited by theartist
Corrected graph to read, "adjusted flux".

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Presented below are two potential F10.7cm scenarios for the remaining SC 24/25 minimum period.

In Scenario (A), the 'Bremen Metric' is not violated, and 'Breakout' occurs by early 2020.  Scenario (A) shown (for the F10.7cm) is comparable to Scenario (A) shown in this thread (for the Mg II Composite).

416237437_F10.7SC2425ScenarioA.thumb.png.a8603d1fdf7204dd59b23af1ca68eee4.png

 

Scenario (C) is an example case of the 'The Panel' prediction (discussed in this thread).  Note the projected F10.7cm in Scenario (C) is very similar to what actually occurred eleven years ago for SC 23/24. The Tentative Solar Minimum in this scenario occurs at a date earlier than shown for Scenario (B) in this thread.2108355856_F10.7SC2425ScenarioC.thumb.png.f92891332ad1e412311c3e3dd152e2ff.png

Edited by theartist
Fixed location of solar minimum on Scenario (C) (to match SC23/24).

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What follows is an inspection of all the solar minimum periods since inception of the F10.7cm.

First, we plot the raw data for all cycles:1342703614_F10.7cmraw.thumb.png.ffeac43efd3510dc8a69f0402fdc213c.png

The next plot is all of the data after simple smoothing.946071623_F10.7cmsmoothed.thumb.png.6cff92d2db5bd8150f333286675d3c56.png

 

The plots that follow are a three-year window of each solar cycle’s minimum period; both raw data and smoothed data are plotted for each cycle.

1096942287_F10.7SC1819raw.thumb.png.dcdc5fa4fadd2aa703d1a40e9ac46dc0.png134086422_F10.7SC1819smoothed.thumb.png.18b94d59af1a083b5a9c73c8de005c8c.png

231099059_F10.7SC1920raw.thumb.png.f2b21b8be7c3dcb968733f861b379553.png474191113_F10.7SC1920smoothed.thumb.png.94f6f0013de32d6253801a841200ebfc.png

767752965_F10.7SC2021raw.thumb.png.bb60b0722f5dcc735ae621c70a152649.png728799246_F10.7SC2021smoothed.thumb.png.4b43a6d492b004510493150235ffa001.png

1772130038_F10.7SC2122raw.thumb.png.0b46827f7a6f07c55d6c9af6fe72b84d.png1748094672_F10.7SC2122smoothed.thumb.png.a1bf4d640c16c0d2c070e24df4b2b475.png

1800577070_F10.7SC2223raw.thumb.png.b6ddb72eb7954346008e82d201ecf298.png187730999_F10.7SC2223smoothed.thumb.png.c0eb92855792fe93127964f3f5bf44d2.png

1037941862_F10.7SC2324raw.thumb.png.cc34ef49c0381ccbd27caca011be99a9.png422724368_F10.7SC2324smoothedx.thumb.png.97ba2a32f2666342240c41847d675068.png

13475805_F10.7SC2425rawx.thumb.png.858b179510c11357f20a215978c882dc.png2286465_F10.7SC2425smoothedx.thumb.png.c1270164457a338e80e20db705721d23.png

 

It is quite apparent from the graphs that SC23/24, and the beginnings of SC24/25, are dramatically lower in 10.7cm Flux than the earlier cycles.

If the 'Bremen Metric' holds up, and 'Breakout' occurs in or before early 2020, then the SC 24/25 minimum period will have been more 'energetic' (i.e., registering more microwave radio energy), on average, than the SC 23/24 period.  Conversely, if the 'Bremen Metric' breaks down, the SC 24/25 minimum period could eventually be less 'energetic', on average overall, than the SC 23/24 period.  We should have a pretty good idea, either way, within 3-4 months from now.

Edited by theartist

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When I first observed the large spikes in the raw F10.7cm data (plotted above, and repeated below as seen at the LISIRD site), I wondered whether they represented a 'measurement error' that had not been corrected.  However, being a ground-based instrument, one would think the authorities would have eventually taken measures to fix a repeated error systemic to their recording/measurement apparatus.  I then went back through the spaceweatherlive archive and checked a number of those spikes and determined that they were indeed associated with days having elevated solar activity (including flares).  I lack a reasonable explanation for yesterday's boost, and I hope someone more knowledgeable on the matter can weigh in.

1209770415_ScreenShot2019-09-08at6_16_08AM.thumb.png.f778731bd8eed277a4bfb94c0e8e8ea1.png

The following paper gives an overall review of the F10.7cm measurement, in attempt to answer questions: The 10.7 cm solar radio flux (F10.7); K. F. Tapping.  It mentions the possibility of rapidly varying 'radio bursts' occurring on minute timescales.  However, there is also mention of the possibility of radar sources of error in the early days, before relocation of the measurement site.

Edited by theartist

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20 hours ago, theartist said:

We just had a very uncharacteristic boost in the F10.7cm today, per the figure below:

1514260118_F10.7cm2019-09-07.thumb.png.bb9688142fb12b67d82d35b280b6ee90.png (data source).

That was a four-point bump within three hours!...very strange.

I likewise did a double take when I saw that, but as http://www.solen.info/solar noted, “(t)he measurement at 20h UT was erroneous (outside the 3% error range) and was therefore replaced by the measurement at 17h UT).

Usually when there is a spike like that it is a “flare enhanced” reading—and there was certainly no flare enhancement yesterday, LOL!

So, given the 17:00 value of 69.7 and 69.9 for 23:00, I’d just split the baby and call it 69.8 P=).

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Kaimbridge, you might want to take another look:

189131331_9-8-19F10_7cm.thumb.png.a7be4b0bc082e4a10fcad1a95b0156b4.png

I've highlighted, with arrows, activity that was occurring on the sun during the time-windows in which the anomalous(?) F10.7cm readings were recorded:

527728789_9-7-19F10_7cm.thumb.jpg.109704130bc820a28cda822f7a943274.jpg151761803_9-8-19F10_7cm.thumb.jpg.dcfc62f253ecafa43b33430abe0e89ac.jpg

Maybe those readings were legitimate solar radio bursts related to the highlighted activity?

Here is a link to the movie where one can check for themselves:  https://sdo.gsfc.nasa.gov/data/latest48.php?q=0304

Edited by theartist

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17 hours ago, theartist said:

Maybe those readings were legitimate solar radio bursts related to the highlighted activity?

After further inspection, I don't think those events, by themselves, are enough to engender the solar flux boost, since they are not particularly unique to what is happening in the current solar environment.

Edited by theartist

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What a difference in just a couple of weeks:

1756632297_ScreenShot2019-09-10at4_35_31PM.thumb.png.f169d4a8cd4cd48b5b17a544ee32ca96.png2008875871_ScreenShot2019-09-10at4_35_59PM.thumb.png.d15617e28d49289657056aa5940ded7b.png

There are no new sunspots....what has changed.  Whatever has changed, is it a precursor to a longterm trend?

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I noticed as soon as the flux ticked up there were very pronounced jets appearing in the polar region, larger than what I’ve seen lately. Related perhaps? I’m probably wrong.

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22 hours ago, Covert Goat said:

there were very pronounced jets appearing in the polar region

Hi.  I think the gaseous objects I point to in the 304Angstrom images above are prominences.  Are you referring to similar activity with the term "pronounced jets", or something else?  

 

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On 9/10/2019 at 4:39 PM, theartist said:

There are no new sunspots....what has changed.

How quickly I forgot, there WAS a small sunspot region at the first of this month, and although the sunspots quickly disappeared, maybe(?) the sun has not 'relaxed' back to the depths of solar minimum lows (although that does not explain the anomalous spikes, including the one on 7/26/19).

452343237_RecentF10_7cm.thumb.png.4e1ae3d042c1379c7ee8bf0b3461d9d4.png

Edited by theartist

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On 9/11/2019 at 5:14 PM, theartist said:

Hi.  I think the gaseous objects I point to in the 304Angstrom images above are prominences.  Are you referring to similar activity with the term "pronounced jets", or something else?  

 

Ahh that could be the correct terminology. No those aren’t at the same location. It is gone now but when the flux was around 74, it was closer to 90 degrees latitude.

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Interesting.  I wonder if little 'insignificant' stuff like this bump in the microwave energy, apparently apart from typical 'thermal gyroresonance' above active regions, can hold clues to the bigger picture; e.g., does the sun fusion process resonate (like a beating heart)?

The 'bump' I'm referring to is not the 'spikes', but rather, the lack of the average flux not yet returning to the previous lows (although the 'spikes' could be interrelated with that.)

Edited by theartist

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1 hour ago, Covert Goat said:

I wonder if other stars are this dynamic.

Actually, this is not 'dynamic', for our sun, relatively speaking.  When the sun is this quiet during solar minimum, it affords us the opportunity to perform 'microscopic evaluation' of flux response to at least try and pin it on a particular type of activity.  Generally, when the sun is more active, we would not be able to discern which particular phenomenon is moving the flux around here and there, by just a few points.  A few months ago, I could directly see a correlation of radio flux boost corresponding to the advent of a sunspot (in conjunction with its very minor flaring).

Another reason I'm paying close attention to the flux down here is to see when 'bottoming-out' for SC24 occurs.

Regarding other stars, I'm sure they can vary a great deal, depending upon their age.  

I thought that article you referenced on the observed dark spots on other stars was pretty interesting.  However, it wasn't clear whether the darkened areas they were seeing were sunspots, or possibly coronal holes, since the imaging resolution was pretty poor.

---------------------       ---------------------       ---------------------

The moving around of the solar radio flux by a few points, down here at solar minimum, when there doesn't appear to be any discernible activity behind it, is interesting in itself.  Maybe there is an answer (or a scientific paper yet to be written) out there to explain it.

But maybe a reason for elevated F10.7cm flux without sunspots is already being discussed, per the Svalgaard paper I referenced recently over in the thread titled, Article published on Nature.com predicts new Maunder Minimum, wherein we read:

"There is a minimum field strength in visible spots of about 1500 Gauss(0.15 T), and as that 1500 G threshold is approached, magnetic fields appear at the solar surface which do not seem to form dark sunspots or pores.  ...the photospheric flux emergence in such cases may take place in flux tubes with fields too weak, or too small a diameter, to form sunspots..."

1336625336_paperstatementonfluxandspots.thumb.png.3033987dfc2e4688d73f056ce797f5ff.png

And,  "(the) stable relationship between the 10.7 flux and the sunspot number...has steadily deteriorated in the past decade to the point where the sunspot number for a given flux has decreased by about a third."

Edited by theartist

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Thanks for the response. I’ve read that Nature paper and some of the comments being posted on academic sites. Sadly, the situation has devolved into in-fighting about global warming and the discussion about minimum has disappeared.

I keep up on direct imaging of other stars, and recall reading in the paper about Zeta Re that not only was Doppler imaging used but also interferometry, so they were able to discern that there was increased levels of magnetism where the dark spots were.

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"The 10.7cm Solar Flux is currently one of the best indices of solar activity we have. It now forms a consistent, uninterrupted database covering more than 50 years." (link)  

The following statement has held true for the F10.7cm Flux since its inception in 1944:  "The Solar Minimum Nadir in a solar cycle's solar minimum period has always occurred within 3 months of the minimum value of the monthly average of Adjusted F10.7cm."

Up to this point in the current SC 24/25 solar cycle transition, the minimum value of the monthly average of Adjusted F10.7cm occurred 10 11 months ago, back in 2018 December November. Obviously, in order for the above statement to hold true for the current cycle transition, we will have to see the Adjusted F10.7cm proceed to a sustained period of low values we have not yet seen in this cycle. 🤪

So then, just how deep is this solar minimum going to go?😳

Edited by theartist
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Does the flux rise dramatically at the end of minimum or is it gradual? There are a few small active regions but nothing to write home about. I assume this is breaking all current models?

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One of the more concrete things we know regarding solar activity is that the flux and sunspot number have historically mirrored each other very well; this is demonstrated mathematically with either a linear regression, or a polynomial fit (for a little more finesse), per discussion in this paper, "The Solar Flux and Sunspot Number; A Long-Trend Analysis"

Now then, Svaalgard (as pointed out above in his six year old paper) was indicating that the relationship between the two had "steadily deteriorated in the past decade to the point where the sunspot number for a given flux has decreased by about a third."  But the more recent paper from 2018 I just cited points out that there was only a blip in the correlation for both SC24 and SC21. 

Generally, it is observed that the rate of rise in solar flux at the beginning of a solar cycle correlates with the strength of the cycle, i.e., the Waldemeir Effect; strong cycles rise to their maximum faster than weak cycles.

------------------------------       ------------------------------       ------------------------------

On 8/12/2019 at 4:52 AM, theartist said:

the Crossover

Today the Observed Flux and Adjusted Flux were equivalent (proceeding into 'the Crossover' discussed at the beginning of this thread):1831581777_Fluxon10-4.thumb.png.927c771d05e6c79a2dde5f048699c343.png:

 

Edited by theartist
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On 9/10/2019 at 8:16 PM, Covert Goat said:

I noticed as soon as the flux ticked up there were very pronounced jets appearing in the polar region, larger than what I’ve seen lately.

Hmmm....maybe you were seeing polar X-ray jets? These are described in the following:

1048375340_ScreenShot2019-10-04at4_54_58PM.thumb.png.8308fa5596740dd8429ced8bd2c19378.png (source)

 

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Ahh yes that’s definitely it. It was quite large in size, at least 4 🌎. I find the polar regions of the sun very interesting, been wondering if there’s some vortex structure like Saturn (amongst some other issues). Too bad we won’t find out until the ESA/NASA Solar Orbiter arrives at the higher latitudes in 2026. After the dynamics that showed up at Jupiter’s poles when the first Juno pics started flowing back, I think anything could be possible.

I wonder if we will still be in solar minimum then? 😎

Edited by Covert Goat
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