I read that the Sun's brightness increased by 0.036 percent from 1986 to 1996. Can this be a...

Scientific American ^ | December 22, 1997 | Anne M. Waple

[AFPhys]

The reporter and scientist who wrote that article jumped the gun. They were wrong. That was INDEED a cycle 24 spot, but that is not how the solar cycle is reckoned.

[ETL]

I think what your link is referring to is the *peak* (or ‘maximum’) of solar cycle 24, not it’s beginning. The peak of SC-24 is due in 2011 or 2012, possibly later because of this unusually long and deep minimum period we are in.

[AFPhys]

The solar cycle is reckoned to have begun when the minimum is established. There have been cycles that has not be definitely determined for 2-3 years after the minimum. In fact, I believe they adjusted the start date of cycle 23 some 2 yrs afterward.

Here are two sources that definitively show that cycle23 is still being added to:

http://en.wikipedia.org/wiki/List_of_solar_cycles

and here is a very good solar scientist - see the table at the bottom of the page
http://www.solen.info/solar/

[ETL]

“Even more significant is the fact that four of the five sunspot groups belonged to Solar Cycle 24, the long-awaited next installment of the sun’s 11-year solar cycle. “October was the first time we’ve seen sunspots from new Solar Cycle 24 outnumbering spots from old Solar Cycle 23. It’s a good sign that the new cycle is taking off.”

Old Solar Cycle 23 peaked in 2000 and has since decayed to low levels. Meanwhile, new Solar Cycle 24 has struggled to get started. 2008 is a year of overlap with both cycles weakly active at the same time. From January to September, the sun produced a total of 22 sunspot groups; 82% of them belonged to old Cycle 23. October added five more; but this time 80% belonged to Cycle 24. The tables have turned.”

http://science.nasa.gov/headlines/y2008/07nov_signsoflife.htm
_____________________________________

Sun Shows Signs Of Life: Long-Awaited Solar Cycle 24 Starting To Take Off

ScienceDaily (Nov. 12, 2008) — After two-plus years of few sunspots, even fewer solar flares, and a generally eerie calm, the sun is finally showing signs of life.

http://www.sciencedaily.com/releases/2008/11/081111230341.htm

_____________________________________

http://www.solarcycle24.com/index2.htm

[AFPhys]

That scientist, Hathaway, who in Oct&Nov was saying that “we're picking up now” is the one who jumped the gun in January. The committee of which he is a kingpin initially predicted that the minimum was going to be Jan 2008, so he was overly excited when the first C24 spots appeared then. Since that time, he has been hoping against hope that his prediction will not be any more months wrong.

Here was a prediction of his, from 2003:
“Nothing’s wrong,” reassures Hathaway. “but sunspot counts averaged over many weeks are still declining as predicted. We're still on course for a solar minimum in 2006.
http://www.nasa.gov/vision/universe/solarsystem/12nov_haywire_prt.htm

He is heavily invested in his predictions of another HUGE solar cycle24 (graph on bottom of page):
http://science.nasa.gov/headlines/y2006/21dec_cycle24.htm

NO ONE still thinks this is at all possible. He is one of the big movers behind the NOAA prediction here: http://www.swpc.noaa.gov/SolarCycle/SC24/index.html. He has major egg on his face, and so every blip up in activity makes him get excited. Meanwhile, on the other side of the ledger, the solar scientists who were looking at solar dynamics have been calling for a low activity and long cycle 24.

Look at what happened to the months since his Oct/Nov excitement: we're even lower in activity than we were in the months before that where he was so sure that was the bottom. Again, I refer to the Solar-Terrestial Activity Report:
http://www.solen.info/solar/

Hathaway may have been one of NASA’s top predictors, but it is now clear that his algorithms are not working, but for over a dozen years, he was numero uno. It is not good to look anything he says now as anything like having a scientific detachment.

At least he recognizes that Jan2008 was NOT the Start of C24
“Decaying solar cycle 23 (the one we are experiencing now) has so far lasted 142 months” which means that as of Nov, he was saying that the C23 would end no sooner than Mar08. http://science.nasa.gov/headlines/y2008/11jul_solarcycleupdate.htm It appears he likes the 13mo moving average for the min. Right now, that lies at 1.3, well below the 13mo avg in Nov08 of 5.7.

Anyway, I'm not going to say much more about this.

Yes, the first Cycle 24 spot was in Jan08, but that did not mark the start of Cycle24, as was erroneously reported in that article. Somewhere I have seen that article officially repudiated, but I haven't seen that in digging up all the stuff I've presented here.

I may make one more attempt to specifically locate that article, and if so, I'll refer you to it, but other than that, I won't be making another comment about this.

Bottom Line: Hathaway was predicting a 10yr cycle 23, and it is now over 12.5 yr. This has VERY big implications for weather, as I've written before. He was also predicting a very strong cycle24. Though he is a kingpin on the "prediction committee", the chairman of that committee is now not consulting with him or anyone, probably because their guesses have been useless.

Two bottom line before and after graphs.

Mar.2007 predictions

Current (Jan08 predictions adjusted by Chairman)

[ETL]

Solar cycle transitions are determined by magnetic polarity reversals, not the presence or absence of sunspots.

[ETL]

"Horace W. Babcock proposed in 1961 a qualitative model for the dynamics of the solar outer layers:

* The start of the 22-year cycle begins with a well-established dipole field component aligned along the solar rotational axis. The field lines tend to be held by the highly conductive solar plasma of the solar surface.

* The solar surface plasma rotation rate is different at different latitudes, and the rotation rate is 20 percent faster at the equator than at the poles (one rotation every 27 days). Consequently, the magnetic field lines are wrapped by 20 percent every 27 days.

* After many rotations, the field lines become highly twisted and bundled, increasing their intensity, and the resulting buoyancy lifts the bundle to the solar surface, forming a bipolar field that appears as two spots, being kinks in the field lines.

* The sunspots result from the strong local magnetic fields in the solar surface that exclude the light-emitting solar plasma and appear as darkened spots on the solar surface.

* The leading spot of the bipolar field has the same polarity as the solar hemisphere, and the trailing spot is of opposite polarity. The leading spot of the bipolar field tends to migrate towards the equator, while the trailing spot of opposite polarity migrates towards the solar pole of the respective hemisphere with a resultant reduction of the solar dipole moment. This process of sunspot formation and migration continues until the solar dipole field reverses (after about 11 years).

* The solar dipole field, through similar processes, reverses again at the end of the 22-year cycle.

* The magnetic field of the spot at the equator sometimes weakens, allowing an influx of coronal plasma that increases the internal pressure and forms a magnetic bubble which may burst and produce an ejection of coronal mass, leaving a coronal hole with open field lines. Such a coronal mass ejections are a source of the high-speed solar wind.

* The fluctuations in the bundled fields convert magnetic field energy into plasma heating, producing emission of electromagnetic radiation as intense ultraviolet (UV) and X-rays."

http://en.wikipedia.org/wiki/Babcock_Model
_________________________________________________

"Different parts of the Sun rotate at different speeds. The Sun's equator spins fastest, and the poles spin more slowly. This causes the Sun's magnetic field to get all tangled up over time. Loops in the tangled magnetic field poke through the Sun's surface sometimes. When they do, they make sunspots."
Windows to the Universe original artwork.

http://www.windows.ucar.edu/tour/link=/sun/Solar_interior/Sun_layers/differential_rotation.html

[AFPhys]

Like the one mentioned here by Hathaway?

http://news.softpedia.com/news/Backward-Sunspot-Could-Fortell-Enormous-Solar-Cycle-33025.shtml

I’m sorry. You are right in all that you have said except that Cycle 24 has officially begun. We don’t know yet when the start of C24 is. Explore these two solar experts, and others if you like.:
http://users.telenet.be/j.janssens/Engwelcome.html
http://www.leif.org/research/

As well as Jan Alvestad’s Solar-Terrestial page I linked earlier. Solar minimum which IS the start of Cycle24 has not yet been determined.

[ETL]

Solar minimum which IS the start of Cycle24 has not yet been determined.

Could you please link to a credible source where it is clearly stated that a new solar cycle is defined as being the point of solar minimum? (as opposed to the first appearance of reversely polarized upper-latitude sunspot pairs)

From March of 2008...

"New solar cycles always begin with a high-latitude, reversed polarity sunspot. High latitude refers to the Sun's grid of latitude and longitude; old sunspots congregate near the Sun's equator and new sunspots appear higher, at around 25-30 degrees latitude. Reversed polarity means a sunspot with opposite magnetic polarity compared to sunspots from the previous solar cycle, such as the one detected on the 4 January this year. However, Solar Cycle 23 has not yet ended, and it may run concurrently with the new cycle for up to a year while sunspots from the old cycle become less numerous."

http://www.astronomynow.com/news/080304solarcycle/

_____________________________________________________

"The physical basis of the solar cycle was elucidated in the early twentieth century by George Ellery Hale and collaborators, who in 1908 showed that sunspots were strongly magnetized (this was the first detection of magnetic fields outside the Earth), and in 1919 went on to show that the magnetic polarity of sunspot pairs:

* Is always the same in a given solar hemisphere throughout a given sunspot cycle;

* Is opposite across hemispheres throughout a cycle;

* Reverses itself in both hemispheres from one sunspot cycle to the next.

Hale's observations revealed that the solar cycle is a magnetic cycle with an average duration of 22 years. However, because very nearly all manifestations of the solar cycle are insensitive to magnetic polarity, it remains common usage to speak of the "11-year solar cycle". ..."

http://en.wikipedia.org/wiki/Solar_cycle

[lepton]

As an aside, the correlations are based upon adjusted climate figures. Steve McIntyre, while not condoning the solar theories, noted that fixing the known-to-be-false bucket adjustments to sea surface temperatures changes the simple correlations to around .8.

[AFPhys]

Could you please link to a credible source where it is clearly stated that a new solar cycle is defined as being the point of solar minimum? (as opposed to the first appearance of reversely polarized upper-latitude sunspot pairs)
-—<>-—<>-—<>-—<>-—<>-—

EVERY credible source says that the solar cycle start is defined as the point of solar minimum. The REASON is due to such phenomena as double humped maximums (which have so far not been true in minimums) and such silly puny spots from other cycles such as the one I linked in post#48, which people such as Hathaway love to highlight when they support their pet theories. Hathaway, is OK, don't get me wrong, but he has been REALLY wrong this last decade and has gotten really obsessive about trying to keep face. You really have to disregard what he says. I'll link his predictions later on.

There would be NO WAY to determine SS Cycles historically since Magnetometer readings are only a couple decades old. In addition, do you call that post#48 spot as truly existing? Far too much room for dispute. It is bad enough now that we are calling so many of these “microspots” sunspots. Many of those would never have been seen as few as 2 decades ago! Each such spot bumps the “monthly count” up by 0.3 each day it is “seen”! Far too much latitude for error when comparing with history. We have to attempt to remain consistent. I've already had an exchange of notes with the author of SpaceWeather.com due to counting of Microspots. I see that SIDC REMOVED one of theirs, finally, from their count last month.

Anyway - to your question:

Here are “credible sources” according to SIDC:
http://sidc.oma.be/educational/classification.php#Gloss

OULU: http://www.oulu.fi/~spaceweb/textbook/cycle.html
“It has been agreed that a cycle starts from an activity minimum.”

IPS: http://www.ips.gov.au/Educational/2/3/4
“The arrival (or non-arrival) of new cycle sunspots can tell us about when the solar cycle will end - called solar minimum. For past solar cycles, the first sunspots of Cycle 20 were seen 13 months prior to solar minimum; for Cycle 21 it was 19 months; and for Cycle 22 the first spots occurred 18 months before minimum. So, when finally we see the first Cycle 23 region then we will know that minimum is 13-19 months away.”

Stanford: http://solar-center.stanford.edu/gloss.html
“Solar Minimum: The month(s) during the solar cycle when the 12-month mean of monthly average sunspot numbers reaches a minimum.”

Jan Alvestad (foremost expert in radio/solar phenomena) https://www.arrl.org/arrlletter/98/980320/
“...the best and most objective way to plot the month-by-month cycle progress comparisons is to always start with the minimum between cycles. This is because it is difficult with so few cycles to develop a general definition.”

http://www.solen.info/solar/cyclcomp.html
“Please note that the start dates for each cycle is calculated using the 13-month smoothed monthly mean sunspot number. One advantage of using this statistical (numerical) approach is that the start month of a solar cycle is the same as the month of the solar minimum. It is possible to use other criteria to separate solar minimum and the start of a solar sunspot cycle, however, which criteria to use and how much importance each is given, unfortunately leaves room for individual opinion.”

The major dispute right now is whether to use a 12 month or 13 month average for the minimum. The average is centered on the month, which some authors don't seem to understand, and so they “call” the minimum 6 months late.

I hope this answers your queries of me sufficiently. If it doesn't, frankly, you're on your own from here out.

Finally, here's Hathaway's floating “predictions” - - - and note that right now, they are automatically pushing that prediction out by a month for each month that we're not yet at minimum. Right now, given there has been one microspot in April, it is clear we STILL are not sure when min will be - and we're up to Oct-Nov08 as of now.

[AFPhys]

Sorry: I didn’t find the chart I wa looking for. I’ll get it later today,

[MayflowerMadam]

We’re DOOOOOOMED!

[AFPhys]

I just ran across Hathaway's predictions. Though I first saw this animation on SolarCycle24.com, it has now found a home on Wiki, so I'll put that link here:

Dr. David Hathaway's Predictions for Solar Cycle 24:

[AFPhys]

I just note that the graphs and pages that I linked to in this earlier post have been changed. My fault, probably, linking to changeable graphics. The result is that the predictions Hathaway made in the years preceding that post are not clear from my writing.

Bottom line is that Hathaway and NASA had been predicting a SC24 larger than SC23 - I believe with sunspot number exceeding 160. That data is available somewhere: I believe via papers by Svalgaard. As of today, the sunspot number appears to have peaked at numbers below 70, as some Russian and Finish scientists argued would occur.