Solar cycle #24

[Jens]

In the first three months of this year, the sun was active most of the time. We've now had a stretch of four days without any spots. Is it just a normal part of the process statistically, or would that be unusual normally?

[flynjack1]

Probably just taking a breather after the flurry of activity. I doubt it is unusual unless it extends out for a month or so.

[George]

A nice storm was discovered today at Solar Stormwatch, though it doesn't seem to be heading our way.

[Jens]

Does anybody know where I can find a chart of spotless days by year? It's pretty easy to find a chart of the most spotless years of the last 50 years or century, but I can't seem to find a list year by year with how many spotless days there were. I'm sort of wondering how many spotless days there are typically in a year at the solar maximum. Would it typically be zero, or even at maximum are there occasional lulls?

[William]

Does anybody know where I can find a chart of spotless days by year? It's pretty easy to find a chart of the most spotless years of the last 50 years or century, but I can't seem to find a list year by year with how many spotless days there were. I'm sort of wondering how many spotless days there are typically in a year at the solar maximum. Would it typically be zero, or even at maximum are there occasional lulls?

Jens,

I could not find a presentation of sunspotless days in the format you are looking for. The sunspot data over the last 150 years is available here:

http://sidc.oma.be/sunspot-data/dailyssn.php

You could answer your question by plotting that data and correlating with the solar cycle minimums and maximums.

Counting the number of sunspots in only one observational parameter. The length of time that the sunspot remains on the surface of the sun before it dissipates , the latitude at which it was formed, and the hemisphere that it was formed is tracked and analyzed, as changes must be connected with solar processes.

The solar 24 sunspots have occurred at lower latitudes than past solar cycles and have a shorter lifetime on the surface of the sun. The shorter sunspot life time is probably due to the linear decrease in the magnetic field strength of new individual sunspots that Livingston and Penn observed.

The current solar magnetic cycle prediction is for a Dalton like solar minimum with a chance of Maunder minimum. That however is only an educated guess based how the sun has been observed to change in the last 150 years.

This is interesting.

http://sidc.oma.be/html/wnosuf.html

This is a link to janssens' sunspot summary that compares solar cycle 24 to other solar cycles.

http://users.telenet.be/j.janssens/S.../Spotless.html

[Atraveller]

13 Day stretch of no spots...

The sun seems to have gone quiet again. But the SDO is getting some amazing shots.

http://www.spaceweather.com/

[Tenshu]

I heard a story that a satelight got taken out by a solar storm recently, does that mean they happen all the time?

[Atraveller]

I heard a story that a satelight got taken out by a solar storm recently, does that mean they happen all the time?

Do take a look at the space weather site linked to in the post above. The sun is an amazing dynamic star. There are geomagnetic storms, solar flares, and coronal mass ejections, all of which can take out delicate electronics, and potentially satellites.

[Jens]

An article in the New Scientist says the sun is still behaving strangely, which is sort of an answer to a question I asked a number of weeks ago. Apparently the start-up is not as rapid as usual.

[flynjack1]

Interesting article, I particularly found the discussion on the effects of UV radiation on the ozone layer of interest. The old Irish curse of may you live in interesting times comes to mind.

[mugaliens]

I found it interesting that TSI (total solar irradiance) dippped to the same level during the previous three solar minima, despite variations in output. During this minima, however, TSI dropped to slightly lower levels. Mike Lockwood at the University of Reading, UK noticed this effect, combined with the significantly prolonged reduction in sunspot number, and reports it lends credence to the correllation between the Maunder Minimum and frigid European temps between 1645 and 1715.

I was also intrigued that ozone production is both increased by increasing UV radiation, while UV radiation absorbtion is similarly increased by additional ozen, thereby revealing a mechanism that magnifies the effect of fluctuations in the UV radiation.

[mantiss]

It's alive!

Auroras spotted as far south as Wisconsin and more on the way, those at higher latitudes should ready their photo gear to record another wave of northern lights.

[William]

It will be interesting to see how quickly cycle 24 ramps up and ramps down. The Maunder minimum cycle was preceded by a rump cycle.

This graph compares the area of the sun that is covered with sunspots and the latitude of the sunspots for past solar cycles. As noted in the graph, solar cycle 24 is was very late, the number of spotless day during the low was the lowest in a 100 years, and the new sunspots appear to be at lower latitudes on than is normal for this period (start of the rise) of solar cycle.

http://solarscience.msfc.nasa.gov/images/bfly.gif

[William]

This graph compares solar cycle 24 to solar cycle 21, 22, and 23. As noted in the graph solar cycle 24 is producing significantly fewer sunspots at this stage in the solar cycle as compared to solar cycle 21, 22, and 23.

http://www.solen.info/solar/cyclcomp.html

[Atraveller]

Looks like solar cycle 24 is finally heating up. Sun spot number is up around 134 today.

And there is another X-flare: http://www.swpc.noaa.gov/rt_plots/xray_5m.html

[William]

There continues to be observational evidence that solar cycle 24 is a rump cycle that precedes either a Maunder minimum or a Dalton minimum.

A significant portion of the sunspots for cycle 24 are spores. Spores are small sunspots that dissapate in a few days. If you look at the sunspot record there were a couple of sunspotless days a few months ago. It is unusual to go from a sunspot count of zero to 135 in a few months.

The solar magnetic field has reversed which normally occurs at the peak of the cycle.

The large sunspots that do appear, are distorted which is the reason for flares.

As noted above Livingston and Penn have observed that each newly produced sunspot has less and less magnetic strength. If the magnetic field decay trend continuous the sun will nolonger be capable of producing sunspots in 2015 based on a linear extapolation of the trend.

Some solar specialists are comparing solar cycle 24 to solar cycle 14. A link to solar cycle 24 is attached below. There are wide swings in sunspot counts in solar cycle 14.

http://www.leif.org/research/SC14.png

[William]

What is currently happening to the sun is not understood.

There has been the longest sunspotless period in a hundred years. There is Livingstons and Penn's observation that the magnetic field strength of newly formed sunspots is less and less. Livingston and Penn note the sun will not be able to produce sunspots by 2015 if the trend is continues.

Mike Lockwood notes the sun has enterred into a Maunder minimum or Dalton minimum 24 times in the last 1000 years. In the same article there is a note that extremely cold winters concide with the minimums and changes to the jet stream which we are currently observing.

http://www.newscientist.com/article/...rue#bx276408B1

The sunspot forecast
Although sunspots are making a belated comeback after the protracted solar minimum, the signs are that all is not well. For decades, William Livingston at the National Solar Observatory in Tucson, Arizona, has been measuring the strength of the magnetic fields which puncture the sun's surface and cause the spots to develop. Last year, he and colleague Matt Penn pointed out that the average strength of sunspot magnetic fields has been sliding dramatically since 1995.

If the trend continues, in just five years the field will have slipped below the threshold magnetic field needed for sunspots to form.

How likely is this to happen? Mike Lockwood at the University of Reading, UK, has scoured historical data to look for similar periods of solar inactivity, which show up as increases in the occurrence of certain isotopes in ice cores and tree rings. He found 24 such instances in the last few thousand years. On two of those occasions, sunspots all but disappeared for decades. Lockwood puts the chance of this happening now at just 8 per cent.

Only on one occasion did the sunspot number bounce back to record levels. In the majority of cases, the sun continued producing spots albeit at significantly depressed levels. It seems that the sunspot bonanza of last century is over.

[George]

I found this conveyor explanation for several of the odd observations interesting.

[orionjim]

I found this conveyor explanation for several of the odd observations interesting.

The thing that is interesting about that article in Nature Magazine is that one of NASA’s main solar scientists, David Hathaway, is in total disagreement with the model being presented.

If you go to Nature’s site and read the comments at the bottom of the page you will see some of the exchange.

http://www.nature.com/nature/journal...ture09786.html

Jim

[astropaz]

Hey all, not sure if the is the right place to ask but could somebody have a look at the current X-Ray flux data here http://www.swpc.noaa.gov/rt_plots/xray_1m.html and maybe explain what is going on?
I have never seen that before so I would think it's just a glitch but could it be a constant release of energy?

[tusenfem]

Seems to me like a shut down, then a data gap and then the red channel recovered again, whereas the blue channel is still only showing background/noise.

[William]

The issue is not only number of sunspots. The current theory of sunspot production requires the sunspots from the past cycle as the seeds for the next sunspot cycle. The magnetic field strength of newly formed sunspots continues to decline. One result of the declining sunspot magnetic field strength is that the sunspot area of new sunspots continues to decline. If appears solar cycle 24 will lead to a Maunder minimum for solar cycle 25.

http://solarscience.msfc.nasa.gov/predict.shtml

Solar Cycle Prediction
Current prediction for the next sunspot cycle maximum gives a smoothed sunspot number maximum of about 62 in July of 2013. We are currently over two years into Cycle 24. The predicted size would make this the smallest sunspot cycle in nearly 200 years.

[mantiss]

The Maunder Minimum lasted 70-some years... any talk of any single cycle being a Maunder Minimum is just a misnomer, I'd say it should be labelled Maunder Minimum-like but...

[William]

The solar large scale polar field is starting to reverse which based on observation of past solar magnetic cycles indicates that the sun has reached the maximum of this solar magnetic cycle.

This is unusual as solar cycle 24 has been both weak and short in duration. In the past short duration solar magnetic cycles are strong powerful cycles. Solar cycle 24 is the weakest cycle in 200 years. There is observational evidence that there was a similar weak short magnetic cycle prior to the Dalton minimum.

Another unusual observation is the area of individual newly formed sunspots has suddenly started to decrease. That observation is consistent with Livingston and Penn’s observation that the magnetic field strength of newly created sunspots is decreasing linearly. L & P note if the trend continues the sun will no longer be capable of creating new sunspots as old sunspots that are transported from the solar poles to the solar tachocline are believed to be the seed that is amplified at the tachocline to form the new sunspots for the next cycle.

http://wattsupwiththat.files.wordpre...05/sosoon1.png

http://wattsupwiththat.files.wordpre...-2008-now1.png

Source
http://wso.stanford.edu/

http://climate.arm.ac.uk/publications/arlt2.pdf

[mikeg64]

Does this indicate that the sunspot cycle has also reached its maximum and that we will now start to observe a decline in sunspot numbers?

[Superluminal]

Does this indicate that the sunspot cycle has also reached its maximum and that we will now start to observe a decline in sunspot numbers?

No, sunspots should be on the increase for the next 2-3 years.

[mikeg64]

OK certainly make sense from
http://www.swpc.noaa.gov/SolarCycle/

But L&P indicate that this maximum will lower than predicted (not necessarily the time to the next maximum)

So next question what determines the lag between the time between sunspot maximum and the maximum of the magnetic cycle?

A simplistic model for understanding this might be by considering a kind of hysteresis phenomena and in analogy with a soft magnetic material a sharp field reversal is not expected..

[William]

It should be noted that the area of the newly formed sunspots and the lifetime of newly formed sunspots continues to decrease. The magnetic field strength of the newly formed sunspots continues to linearly decrease.

The sunspot count includes smaller and smaller sunspots. The NASA prediction ignores and does not take into account or provide an explanation for the linear reduction in the sunspots’ magnetic field strength. It appears we are going to have an opportunity to observe a once in 2400 year event.

http://www.solen.info/solar/


As noted in Livingston and Penn’s paper above if the trend continues the sun will no longer be capable of producing sunspots.

http://www.bautforum.com/showthread....74#post1661374


Comment:
Sunspots are hypothesized to be created at the solar tachocline which is the name for the region in the sun that separates the convection zone and the radiative zone. Magnetic ropes are created at the tachocline and then released where they float up through the turbulent convection zone to form sunspots on the surface of the sun. The magnetic ropes require a field strength of around 2000 gauss to avoid being torn apart as they float up through the turbulent convection zone.

In the 20th century the solar magnetic cycle was at its highest level in 8000 years. There is evidence in the paleo record (analysis of cosmogenic isotopes that are deposited in ocean sediment and on the ice sheets) of a very strong change cyclic change in the solar magnetic cyclic with a periodicity of 1470 years and 2400 years.

[William]

Sunspots May Vanish by 2015

http://www.eike-klima-energie.eu/upl...gston_penn.pdf


http://adsabs.harvard.edu/abs/2004ApJ...605L..81B

….We have examined the long-term trends in the solar variability that can be deduced from some indirect data and from optical records. We analyzed the radiocarbon measurements for the last 4500 years, based on dendrochronology… last 1700 years, based on auroral records, and the Hoyt-Schatten series of group sunspot numbers. Focusing on periodicities near one and two centuries, which most likely have a solar origin, we conclude that the present epoch is at the onset of an upcoming local minimum in the long-term solar variability. There are some clues that the next minimum will be less deep than the Maunder minimum, but ultimately the relative depth between these two minima will be indicative of the amplitude change of the quasi-two-century solar cycle….

http://www.essc.psu.edu/essc_web/sem...0al%202001.pdf

…The evidence comes from a close correlation between inferred changes in production rates of the cosmogenic nuclides carbon-14 and beryllium-10 and centennial to millennial time scale changes in proxies of drift ice measured in deep-sea sediment cores. A solar forcing mechanism therefore may underlie at least the Holocene segment of the North Atlantic’s 1500-year cycle…

Prolonged minima and the 179-yr cycle of the solar inertial motion by R.Fairbridge and J. Shirley

We employ the JPL long ephemeris DE-102 to study the inertial motion of the Sun for the period A.D. 760–2100. Defining solar orbits with reference to the Sun's successive close approaches to the solar system barycenter, occurring at mean intervals of 19.86 yr, we find simple relationships linking the inertial orientation of the solar orbit and the amplitude of the precessional rotation of the orbit with the occurrence of the principal prolonged solar activity minima of the current millenium (the Wolf, Spörer, and Maunder minima). The progression of the inertial orientation parameter is controlled by the 900-yr great inequity of the motion of Jupiter and Saturn, while the precessional rotation parameter is linked with the 179-yr cycle of the solar inertial motion previously identified by Jose (1965). A new prolonged minimum of solar activity may be imminent.

http://www.springerlink.com/content/w57236105034h657/


http://www.ann-geophys.net/20/115/20...0-115-2002.pdf

..Time comparison of the epochs of high and low solar activity with climate alteration led to the conclusion that the cause of the approx. 2400-year cycle, both in the 14C concentration and in climate of the Earth, appears to be of a solar nature (Dergachev and Chistyakov, 1995)…


…The first basic cycle of solar inertial motion, the cycle of 178.7 years, was found by Jose (1965) in a repetition of solar motion characteristics computed between 1653 and 2060, and most important the time derivative of the Sun's angular momentum was found…

Mechanism for the cyclic warming and cooling

http://science.au.dk/en/news-and-eve...ber-skydaekke/


http://scholar.google.com/url?sa=U&q...ng/VanGeel.pdf

"A number of those Holocene climate cooling phases... most likely of a global nature (eg Magney, 1993; van Geel et al, 1996; Alley et al 1997; Stager & Mayewski, 1997) ... the cooling phases seem to be part of a millennial-scale climatic cycle operating independent of the glacial-interglacial cycles (which are) forced (perhaps paced) by orbit variations."

"... we show here evidence that the variation in solar activity is a cause for the millennial scale climate change."

Last 40 kyrs
Figure 2 in paper. (From data last 40 kyrs)... "conclude that solar forcing of climate, as indicated by high BE10 values, coincided with cold phases of Dansgaar-Oeschger events as shown in O16 records"

Recent Solar Event
"Maunder Minimum (1645-1715) "...coincides with one of the coldest phases of the Little Ice Age... (van Geel et al 1998b)

Periodicity
"Mayewski et al (1997) showed a 1450 yr periodicity in C14 ... from tree rings and ...from glaciochemicial series (NaCl & Dust) from the GISP2 ice core ... believed to reflect changes in polar atmospheric circulation.."

[William]

Analysis of three separate solar parameters published in three new papers indicate the sun is moving towards a Maunder minimum.


http://www.space.com/11960-fading-su...lar-cycle.html

The results of the new studies were announced today (June 14) at the annual meeting of the solar physics division of the American Astronomical Society, which is being held this week at New Mexico State University in Las Cruces.

"This is highly unusual and unexpected," said Frank Hill, associate director of the National Solar Observatory's Solar Synoptic Network. "But the fact that three completely different views of the sun point in the same direction is a powerful indicator that the sunspot cycle may be going into hibernation." ....

Hill is the lead author of one of the studies that used data from the Global Oscillation Network Group to look at characteristics of the solar interior. (The group includes six observing stations around the world.) The astronomers examined an east-west zonal wind flow inside the sun, called torsional oscillation. The latitude of this jet stream matches the new sunspot formation in each cycle, and models successfully predicted the late onset of the current Cycle 24.

"We expected to see the start of the zonal flow for Cycle 25 by now, but we see no sign of it," Hill said. "This indicates that the start of Cycle 25 may be delayed to 2021 or 2022, or may not happen at all."

With more than 13 years of sunspot data collected at the McMath-Pierce Telescope at Kitt Peak in Arizona, Matt Penn and William Livingston observed that the average magnetic field strength declined significantly during Cycle 23 and now into Cycle 24. Consequently, sunspot temperatures have risen, they observed.

If the trend continues, the sun's magnetic field strength will drop below a certain threshold and sunspots will largely disappear; the field no longer will be strong enough to overcome such convective forces on the solar surface.

In a separate study, Richard Altrock, manager of the Air Force's coronal research program at NSO's facility in New Mexico, examined the sun's corona and observed a slowdown of the magnetic activity's usual "rush to the poles."

"Cycle 24 started out late and slow and may not be strong enough to create a rush to the poles, indicating we'll see a very weak solar maximum in 2013, if at all," Altrock said. "If the rush to the poles fails to complete, this creates a tremendous dilemma for the theorists, as it would mean that Cycle 23's magnetic field will not completely disappear from the polar regions. … No one knows what the sun will do in that case."