NOAA Predicts Solar Cycle 24

NOAA via spaceweather.com ^ | May 8, 2009 | NOAA Press release

[ETL]

“Probable” spots don’t count in the official record. The last observed spot was Cycle 23.

Sunspots are dark because they are somewhat cooler than the surrounding solar surface. Field lines are so tightly bundled in these regions that they suppress the local heat energy. However, even though the lines may not always be bundled tight enough to cool these areas sufficiently to produce dark (visible) spots, they still tell us what's going on with the underlying magnetic field, most importantly, the polarity of the 'spot regions'. Sunspots are the circular cross-sections of bundled magnetic field lines which poke out of the sun's surface towards us. But the same phenomenon can be taking place without dark visible spots appearing (when the lines aren't so tightly bundled).

[PreciousLiberty]

All true, and all irrelevant to my point. :-)

[PreciousLiberty]

“Budget season, is it?”

No doubt, especially with the Dems trying to do some show budget cutting (1.5% LOL).

Of course, it’s not at all clear what mitigation can happen on the ground once the forecast is made... ;-)

It is important information for satellites, which can take measures before the storm hits.

[ETL]

all irrelevant to my point.

Not at all. The start of a new solar cycle is based on a reversal of the polarity of the paired circular cross-sections of magnetic field lines. Whether the cross-sections appear dark (as in 'sunspot') has nothing to do with it. Magnetic field lines stream out of one spot and loop back into the other. Therefore there is a 'north spot' and a 'south spot' for each x-section pair. Whether the x-sections are visible as 'sunspots' depends only the *temperature* of the x-sections. The cooler they are (in comparison to the hotter surrounding surface), the darker they are. And that depends on how intensely bundled the poking out, or poking in, field lines are.

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

[cliff630]

A question, ETL.

The sun rotates, but because of the varying behavior
of sunspots, could the axis of the sun's rotation
in turn be rotating. This would be quite weird if
earth behavied similarily but the sun is just a great
big ball of fire.

[ETL]

The sun rotates, but because of the varying behavior of sunspots, could the axis of the sun's rotation in turn be rotating. This would be quite weird if earth behaved similarly...

I doubt if the inclination of the Sun's rotational axis is being influenced by its magnetic activity. The behavior of sunspots is very systematic and follows a steady pattern. The following "Butterfly Diagram" illustrates it very well:

The top diagram ("Butterfly Pattern") shows how regular/consistent a pattern it is. EQ = solar equator. 90 north and south, the Sun's poles.

Enlarged version here:
http://upload.wikimedia.org/wikipedia/commons/1/1e/800px-Sunspot_butterfly_with_graph.gif

http://en.wikipedia.org/wiki/Sunspot
____________________________________________

In regards to the Earth, both its rotational axis and the position of its magnetic poles vary over time.

[ETL]

The sun rotates, but because of the varying behavior of sunspots, could the axis of the sun's rotation in turn be rotating.

Sorry. I think I misread your question. Are you asking if the Sun's rotational axis is, itself, spinning?

[PreciousLiberty]

“Not at all.”

Yes. The point to which I was referring was the latest observation of a Cycle 23 spot. Nothing you posted had anything to do with it. The “dying” active area that came into view was a Cycle 24 area, but had no spots.

As to when Cycle 24 “officially” starts, it has nothing to do with when the _first_ Cycle 24 spot appears, it has to do with when the true minimum is reached. Clearly, it wasn’t last December either. As I said in an earlier post, we’ll only know after the fact...the earliest it could be at this point is about now. Keep an eye out for higher sunspot numbers, including more than one group at once, that will be a good indication that the minimum is ending. That is, of course, unless we’re entering the relatively uncharted territory of a Minimum, where the eleven year cycle goes out the window altogether.

[ETL]

The “dying” active area that came into view was a Cycle 24 area, but had no spots.

I've already explained that the only thing that separates 'sunspots' from other magnetic field line cross-sections is temperature. So it really doesn't matter if we actually see a dark spot there or not. The magnetic reversal shows up on the magnetogram. As for when a new cycle officially begins, it seems it all depends on what the meaning of 'is' is. In this case, does it begin as the NASA expert I linked to described:

Solar Cycle 24 Begins

"On January 4, 2008, a reversed-polarity sunspot appeared—and this signals the start of Solar Cycle 24," says David Hathaway of the Marshall Space Flight Center.

"New solar cycles always begin with a high-latitude, reversed polarity sunspot," explains Hathaway. "Reversed polarity" means a sunspot with opposite magnetic polarity compared to sunspots from the previous solar cycle. "High-latitude" refers to the sun's grid of latitude and longitude. Old cycle spots congregate near the sun's equator. New cycle spots appear higher, around 25 or 30 degrees latitude.

The sunspot that appeared on January 4th fits both these criteria. It was high latitude (30 degrees N) and magnetically reversed. NOAA named the spot AR10981, or "sunspot 981" for short.

http://science.nasa.gov/headlines/y2008/10jan_solarcycle24.htm
__________________________________________

OR, does it begin the way YOU described?

[ETL]

In other words, take the time when there were virtually NO sunspots at all for a 60-70 year stretch (the Maunder Minimum/Little Ice Age, apprx 1645 to 1715). Are you saying there were no new solar cycles during this entire period?

[ETL]

>Are you saying there were no new solar cycles during this entire period?

Or that the Sun’s magnetic field didn’t flip even once during this 60-70 year period? On average it reverses (flips) every 22 years. There are two 11-year solar cycles per full magnetic field reversal.

[cliff630]

I'll try again. I could show you very easily with
my earth globe on a pedestal. There is a circular rim
which is stationary about the equator. Now I can
rotate the globe about the North/South axis.
Imagine, if you will, my globe has the ability to
rotate. Then while it is rotating, I am able to
rotate the spinning globe.

The sun is rotating but the axis about which the sun
itself is rotating is itself rotating. Complete
wild speculation on my part.

If there were a sun spot on the sun, it should appear
on the same latitude, but diappearing as the sun
rotates. If in addition, the sun were also spinning
the spot would appear at differnt latitudes.

Of course, I have no clue of these spinning and
rotating velocities. The point is, if there are
two spots, an observer might think there is but one.

This 11 year cycle of spots is an accelerated version
of our ice ages.

Although with Fourier Series we can find many cycles,
the perturbations are a problem. You've probably
heard of the 12/12/12 apocalypse. That's when all
the planets are lined up. Also on 8/27/09 Mars
will be at its brightest in many thousands of years.
Something to do with Jupiter. Maybe a mirror effect. >

[PreciousLiberty]

"I've already explained that the only thing that separates 'sunspots' from other magnetic field line cross-sections is temperature."

Indeed. However, the interesting point of all this is comparing it to old, historical data taken when there was no way to detect the "invisible" sunspots. Therefore, the invisible ones are not relevant and of no interest - except that sunspot core temperatures appear to be rising, and having all of them get too warm to be seen is an interesting explanation for their scarcity during the Minimums.

http://wattsupwiththat.com/2008/06/02/livingston-and-penn-paper-sunspots-may-vanish-by-2015/

"In this case, does it begin as the NASA expert I linked to described OR, does it begin the way YOU described?"

Yeah, Hathaway was a big cheerleader for an early, short, intense Cycle 24 when it was still plausible. He didn't use very precise language in that article.

Check out this page at NOAA:

http://www.swpc.noaa.gov/SolarCycle/SC24/Statement_01.html

This is a statement from March, 2007 regarding the expected onset of Cycle 24. The pertinent section reads:

"The Solar Cycle 24 Prediction Panel anticipates the solar minimum marking the onset of Cycle 24 will occur in March, 2008 (±6 months). The panel reached this conclusion due to the absence of expected signatures of minimum-like conditions on the Sun at the time of the panel meeting in March, 2007: there have been no high-latitude sunspots observed with the expected Cycle 24 polarity; 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; and activity measures, such as cosmic ray flux, radio flux, and sunspot number, have not yet reached typical solar minimum values."

My emphasis. In other words, solar minimum must be reached before Cycle 24 officially starts, regardless of the presence of Cycle 24 spots. Solar minimum is generally defined to be the low point on a monthly-averaged sunspot number chart. Usually it'll be followed by a rapid increase in sunspot numbers if the new cycle kicks in normally.

If you look at the first graph at:

http://www.swpc.noaa.gov/SolarCycle/index.html

you'll see that so far in 2009 we're right on the bottom of the graph with no uptick. Until there's a significant upward trend on that graph, Cycle 24 will be on hold, in other words we'll still be "in" the minimum (and the hapless panel will still be trying to guess the real onset of Cycle 24). Also note this language on that page:

"Minimum will now occur no earlier than August, 2008. For every month beyond March 2008 that minimum slips, it is necessary to shift the prediction curves by the same amount. SWPC commenced doing so in mid-February and will continue to do so, unless or until the prediction panel sets a new predicted date for the time of solar minimum."

'Shifting the prediction curve' is synonymous with 'shifting Cycle 24' - based strictly on the location of the minimum. I believe it won't be set any earlier than 4/2009, and unless something changes it might be a lot later than that.

I hope this (finally) cleared things up. :-)

[PreciousLiberty]

Second active area now in view - no sunspots.

Now to day 10 in the current spotless streak.

[PreciousLiberty]

A few more things, this will be my last post on the thread unless there's a response:

This is the link for the last visible spot, of the Cycle 23 variety:

http://www.spaceweather.com/archive.php?view=1&day=30&month=04&year=2009

The article I linked at the top included the language:

"Solar Cycle 24 will be the weakest cycle since number 16, which peaked at 78 daily sunspots in 1928"

I'm not sure what "78 daily sunspots" means, but I'm sure it's meant to read "78 sunspot number". The "sunspot number" is calculated as:

sunspot_number = 10 * sunspot_group_count + sunspot_total

So, for example, if there were two sunspot groups, one with three spots, and one with four, the "sunspot number" for the day would be 2*10+7 for a total of 27.

Here's the latest white light, sunspot viewing image from Culgoora, this may change over time but right now it's a blank disc.

Hope it was of some interest...

[PreciousLiberty]

"In other words, take the time when there were virtually NO sunspots at all for a 60-70 year stretch (the Maunder Minimum/Little Ice Age, apprx 1645 to 1715). Are you saying there were no new solar cycles during this entire period?"

I'm going to break my promise of no more posts here, since I didn't respond to this before, plus I thought you'd get a laugh out of today's caption under the spaceweather solar pic.

No, I'm not saying there were no new solar cycles, but it's not at all clear what the periodicity was. Note that this current cycle is weak, and longer than normal, which is a well known relationship. How much longer would it be if it were twice as weak? Of course we don't know how weak the cycles became during the Minimums.

As I noted in #34, there are observations that indicate sunspot core temperatures are warming, at the same time magnetic fluxes are weakening, independent of the 11 year cycle. It could of course stop tomorrow, but the data looked very consistent over the last thirty years or so. We'll know by 2015. ;-)

So, it seems an entirely reasonable hypothesis that core temperatures may rise enough (coupled with a sequence of very weak cycles) that almost all of the spots become of the "invisible" variety, even at solar maximum. That would account for multiple decades of almost no sunspots, even though the cycles could still be going on at a reduced rate and intensity.

Finally, I thought this was funny at spaceweather.com today. Reminiscent of your comments regarding the dead Cycle 24 areas, they replaced the normal visible light solar disc with a magnetogram, with this caption:

'Today's image is a magnetic map of the sun. Two active regions are circled. Their polarity identifies them as members of new Solar Cycle 24, but they lack the dark cores required of true sunspots. So, in spite of these lively magnetic imprints, we must still say "the sun is blank--no sunspots."'

LOL! Pining for sunspots at NASA...

[ETL]

Finally, I thought this was funny at spaceweather.com today. Reminiscent of your comments regarding the dead Cycle 24 areas

Wow! That IS a weird coincidence! I've never seen that issue being raised before. I just reasoned it out myself. Clearly, whether these regions show up as visible 'spots' or not depends only on their temperature. In any case, they DO tell us what is happening with the underlying magnetic field lines. Just as I thought. Thanks for the note.

"Today's image is a magnetic map of the sun. Two active regions are circled. Their polarity identifies them as members of new Solar Cycle 24, but they lack the dark cores required of true sunspots. So, in spite of these lively magnetic imprints, we must still say "the sun is blank--no sunspots." Credit: SOHO/MDI"

Enlarged view (white on left, black on right, upper latitude/northern solar hemisphere = new solar cycle 24 'spots'/regions):

http://spaceweather.com/archive.php?view=1&day=12&month=05&year=2009
_______________________________________________

Realtime and archival images of the Sun from NASA/SOHO (Solar and Heliospheric Observatory).

[current images in various other electromagnetic frequencies. Also a current magnetogram. These images update every 15 minutes or so (I think?).]

http://sohowww.nascom.nasa.gov/data/realtime-images.html

[Straight Vermonter]

The most recent sunspots were from Cycle 23, and as long as that keeps happening Cycle 24 won't officially start.

I'm no expert but I believe the two cycles usually overlap. The spots from the new cycle start in the polar region and move closer to the equator as the cycle matures.

[ETL]

I thought this was funny at spaceweather.com today. Reminiscent of your comments regarding the dead Cycle 24 areas

They're actually not 'dead'. If you observe the current image below you'll see some light patches in that area. These areas are known as 'falculae'. They are actually *hotter* than the surrounding solar surface and therefore show up as lighter in color. They usually accompany sunspots, or in this case potential sunspot regions.

Enlarged version:
http://sohowww.nascom.nasa.gov/data/realtime/mdi_igr/1024/latest.html
______________________________________________-

From NASA's Solar and Heliospheric Observatory's "Not So Frequently Asked Questions" section:

Q-Does the number of sunspots have any effect on the climate here on Earth?

A-Sunspots are slightly cooler areas on the surface of the Sun, due to the intense magnetic fields, so they radiate a little less energy than the surroundings. However, there are usually nearby areas associated with the sunspots that are a little hotter (called falculae), and they more than compensate. The result is that there is a little bit more radiation coming from the Sun when it has more sunspots, but the effect is so small that it has very little impact on the weather and climate on Earth.

However, there are more important indirect effects: sunspots are associated with what we call "active regions", with large magnetic structures containing very hot material (being held in place by the magnetism). This causes more ultraviolet (or UV) radiation (the rays that give you a suntan or sunburn), and extreme ultraviolet radiation (EUV). These types of radiation have an impact on the chemistry of the upper atmosphere (e.g. producing ozone). Since some of these products act as greenhouse gases, the number of sunspots (through association with active regions) may influence the climate in this way.

Many active regions produce giant outflows of material that are called Coronal Mass Ejections. These ejections drag with them some of the more intense magnetic fields that are found in the active regions. The magnetic fields act as a shield for high-energy particles coming from various sources in our galaxy (outside the solar system). These "cosmic rays" (CRs) cause ionization of molecules in the atmosphere, and thereby can cause clouds to form (because the ionized molecules or dust particle can act as "seeds" for drop formation).

If clouds are formed very high in the atmosphere, the net result is a heating of the Earth - it acts as a "blanket" that keeps warmth in.

If clouds are formed lower down in the atmosphere, they reflect sunlight better than they keep heat inside, so the net result is cooling. Which processes are dominant is still a matter of research.

http://sohowww.nascom.nasa.gov/classroom/notsofaq.html#SUNSPOT_CLIMATE
____________________________________________________

NASA graph of sunspot activity over the past 400 years [note the profound lack of sunspot activity during the "Little Ice Age" period (apprx 1650-1720), AND the sharp INCREASE particularly during the past 60 years:

http://science.nasa.gov/ssl/pad/solar/images/ssn_yearly.jpg